Language：English   Publishing type：Research paper (scientific journal)   Publisher：Macromolecular Rapid Communications  

Developing nanovehicles for delivering antibiotics is a promising approach to overcome the issue of antibiotic resistance. This study aims to utilize a polyion complex (PICs) system for developing novel nanovehicles for polymyxin-type antibiotics, which are known as last resort drugs. The formation of antibiotic-based PIC nanostructures is investigated using colistimethate sodium (CMS), an anionic cyclic short peptide, and a series of block catiomers bearing different amounts of guanidinium moieties on their side chains. In addition, only the modified catiomer, and not the unmodified catiomer, self-assembles with CMS, implying the importance of the guanidine moieties for enhancing the interaction between the catiomer and CMS via the formation of multivalent hydrogen bonding. Moreover, micellar and vesicular PIC nanostructures are selectively formed depending on the ratio of the guanidine residues. Size-exclusion chromatography reveals that the encapsulation efficiency of CMS is dependent on the guanidinium modification ratio. The antimicrobial activity of the PIC nanostructures is also confirmed, indicating that the complexation of CMS in the PICs and further release from the PICs successfully occurs.

DOI： 10.1002/marc.202200316

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Language：English   Publishing type：Research paper (scientific journal)  

The formation and dynamic behavior of polyion complex-based vesicles (PICsomes) were examined under charge-balance disrupting conditions, using homo-catiomer and pegylated-aniomer. Under catiomer-rich conditions, an unusual increase in the PICsome size was observed, which was primarily attributed to Ostwald ripening. This growth was triggered by the addition of a homo-catiomer to switch the composition of the PIC membrane. The results provide insight into the design of smart PIC-based systems for functional nanocapsules.

DOI： 10.1246/cl.210037

Language：English   Publishing type：Research paper (scientific journal)  

For the simultaneous delivery of antisense oligonucleotides and their effector enzymes into cells, nanosized vesicular polyion complexes (PICs) were fabricated from oppositely charged polyion pairs of oligonucleotides and poly(ethylene glycol) (PEG)-b-polypeptides. First, the polyion component structures were carefully designed to facilitate a multimolecular (or secondary) association of unit PICs for noncovalent (or chemical cross-linking-free) stabilization of vesicular PICs. Chemically modified, single-stranded oligonucleotides (SSOs) dramatically stabilized the multimolecular associates under physiological conditions, compared to control SSOs without chemical modifications and duplex oligonucleotides. In addition, a high degree of guanidino groups in the polypeptide segment was also crucial for the high stability of multimolecular associates. Dynamic light scattering and transmission electron microscopy revealed the stabilized multimolecular associates to have a 100 nm sized vesicular architecture with a narrow size distribution. The loading number of SSOs per nanovesicle was determined to be ∼2500 using fluorescence correlation spectroscopic analyses with fluorescently labeled SSOs. Furthermore, the nanovesicle stably encapsulated ribonuclease H (RNase H) as an effector enzyme at ∼10 per nanovesicle through simple vortex-mixing with preformed nanovesicles. Ultimately, the RNase H-encapsulated nanovesicle efficiently delivered SSOs with RNase H into cultured cancer cells, thereby eliciting the significantly higher gene knockdown compared with empty nanovesicles (without RNase H) or a mixture of nanovesicles with RNase H without encapsulation. These results demonstrate the great potential of noncovalently stabilized nanovesicles for the codelivery of two varying bio-macromolecule payloads for ensuring their cooperative biological activity.

DOI： 10.1021/acs.biomac.0c01192

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1039/d0cc01750g

Language：Japanese  

Language：Japanese  

DOI： 10.5363/tits.25.4_31

Language：Japanese  

最近の若手アカデミーのシチズンサイエンスに関わる活動や国際会議における議論の内容を交えながら、社会における科学者のあり方について、次世代を担う若手・中堅科学者の立場から論考を行った。

Language：Japanese  

DOI： 10.5363/tits.24.3_52

Language：Japanese  

DOI： 10.5363/tits.23.8_16

Language：English   Publishing type：Research paper (scientific journal)  

Polyion complex vesicles (PICsomes) are characterized by their unique three-layered semipermeable nanomembrane structures, in which a unilamellar PIC layer is sandwiched by poly(ethylene glycol) layers, and have gathered much attention as nano-scaled drug vehicles. Herein, the crosslinking degree of the nanomembrane in the PICsome was controlled systematically for the first time. Permeability of the PICsome nanomembrane was evaluated through a kinetic study of the release of macromolecular cargoes from the PICsome. The degree of crosslinking in the nanomembrane successfully regulated the release behavior. Moreover, the shape and size of the macromolecular solutes were found to be critical factors determining their transport from the inner aqueous phase of the PICsome to the external environment. The results indicate that the unique three-layered structure of PICsome membranes plays a key role in modulating solute transport. These findings will provide a rational strategy for the development of nanomembrane-based controlled-release systems. (C) 2017 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2017.10.062

Language：English   Publishing type：Research paper (scientific journal)  

Polyion complex vesicles (PlCsomes) are polymeric hollow capsules composed of a unique semipermeable membrane, which may represent a versatile platform for constructing drug-loaded nanoformulation. However, it is difficult to retain water-soluble low-molecular weight compounds (LMWCs) in the inner space of PlCsome because of the high permeability of PIC membrane for LMWCs. Herein, we selected mesoporous silica nanoparticle (MSN) as a drug-retaining nanomatrix, and we demonstrated successful encapsulation of MSN into the PlCsome to obtain MSN@PlCsome. The efficacy of MSN loading, a ratio of the amount of MSN encapsulated in the PICsome to the amount of feed MSN, was at most 83%, and the diameter of resulting product was approximately 100 nm. The obtained MSN@PlCsome was stably dispersed under the physiological condition, and showed considerable longevity in blood circulation of mice. Furthermore, the surface of MSN in MSN@PlCsome can be modified without any deterioration of the vesicle structure, obtaining amino-functionalized and sulfonate-functionalized MSN@PlCsomes (A-MSN@PlCsome and S-MSN@PICsome, respectively). Both surface-modified MSN@PlCsomes were successfully loaded with charged water-soluble low-molecular-weight compounds (LMWCs). Particularly, S-MSN@PICsome kept 8 wt % gemcitabine (GEM) per S-MSN, and released it in a sustained manner. GEM-loaded S-MSN@PlCsome demonstrated marked cytotoxicity against cultured tumor cells, and achieved significant in vivo efficacy to suppress the growth of subcutaneously implanted lung tumor via intravenous administration.

DOI： 10.1021/acsbiomaterials.6b00562

Language：English   Publishing type：Research paper (scientific journal)  

Submicrometer-scaled (sub-) self-assembled materials have been developed based on polyion complex (PIC) formation, in particular for biomedical-applications. However, sufficient stability under physiological conditions is required for their practical use. In this study, PIC formation behavior is examined using a block aniomer, poly(ethylene glycol)-b-poly(aspartic acid), and homocatiomers, poly(l-lysine) (LPK) and dendritic poly(l-lysine) (DPK) with different generations, to elucidate the contribution of the dendritic architecture to stability enhancement. LPK-based PIC shows a sub-vesicular structure only at 25 degrees C in the absence of NaCl; in contrast, DPK-based PIC forms a sub-structure under physiological salt concentration and temperature conditions, even when the number of charges of a single molecule is much smaller than that of LPK. Moreover, the formation of sub-vesicular and -spherical micellar structures is dependent on DPK generation. Thus, the molecular backbone architecture of the PIC component plays an important role not only in expanding the preparation conditions and enhancing stability, but also in controlling the self-assembled structures, mainly due to the spatially restricted structures of dendrimers.

DOI： 10.1002/marc.201600171

Language：English   Publishing type：Research paper (scientific journal)  

In atherosclerotic lesions, the endothelial barrier against the bloodstream can become compromised, resulting in the exposure of the extracellular matrix (ECM) and intimal cells beneath. In theory, this allows adequately sized nanocarriers in circulation to infiltrate into the intimal lesion intravascularly. We sought to evaluate this possibility using rat carotid arteries with induced neointima. Cy5-labeled polyethylene glycol-conjugated polyion complex (PIC) micelles and vesicles, with diameters of 40, 100, or 200 nm (PICs-40, PICs-100, and PICs-200, respectively) were intravenously administered to rats after injury to the carotid artery using a balloon catheter. High accumulation and long retention of PICs-40 in the induced neointima was confirmed by in vivo imaging, while the accumulation of PICs-100 and PICs-200 was limited, indicating that the size of nanocarriers is a crucial factor for efficient delivery. Furthermore, epirubicin-incorporated polymeric micelles with a diameter similar to that of PICs-40 showed significant curative effects in rats with induced neointima, in terms of lesion size and cell number. Specific and effective drug delivery to pre-existing neointimal lesions was demonstrated with adequate size control of the nanocarriers. We consider that this nanocarrier-based drug delivery system could be utilized for the treatment of atherosclerosis.

DOI： 10.1021/acs.molpharmaceut.6b00219

Language：English   Publishing type：Research paper (scientific journal)  

The design and construction of nanoreactors are important for biomedical applications of enzymes, but lipid-and polymeric-vesicle-based nanoreactors have some practical limitations. We have succeeded in preparing enzyme-loaded polyion complex vesicles (PICsomes) through a facile protein-loading method. The preservation of enzyme activity was confirmed even after cross-linking of the PICsomes. The crosslinked beta-galactosidase-loaded PICsomes (beta-gal@PICsomes) selectively accumulated in the tumor tissue of mice. Moreover, a model prodrug, HMDER-beta Gal, was successfully converted into a highly fluorescent product, HMDER, at the tumor site, even 4 days after administration of the beta-gal@PICsomes. Intravital confocal microscopy showed continuous production of HMDER and its distribution throughout the tumor tissues. Thus, enzyme-loaded PICsomes are useful for prodrug activation at the tumor site and could be a versatile platform for enzyme delivery in enzyme prodrug therapy.

DOI： 10.1002/anie.201508339

Language：English   Publishing type：Research paper (scientific journal)  

Recently, nanomaterials constructed by molecular self-assembly have gathered much attention to develop nano-devices incorporated with many types of drugs. Particularly, hollow capsules are one of promising materials, and recently, we have developed polyion complex vesicles, PICsomes, as novel polymeric vesicles. The most advantageous feature of PICsomes is its simple preparation process: Typically, they can be prepared by simple mixing of oppositely charged block copolymers consisting of poly(ethylene glycol) (PEG) and charged poly(amino acid)s in an aqueous medium. Moreover, many other unique properties of PICsomes have been reported, such as facile tuning of vesicle sizes ranging from 100-400 nm while keeping monodispersed size distribution, semipermeable vesicle membrane, facile loading of various water-dispersed materials, long blood circulation after crosslinking, excellent tumor accumulation based on the enhanced permeability and retention (EPR) effect, and so on. The present review article describes basic design and synthetic strategy of PICsomes, fundamental properties of PICsomes, and recent applications of PICsomes to drug delivery system.

DOI： 10.2745/dds.31.308

Language：English   Publishing type：Research paper (scientific journal)  

Polyion complex (PIC) formation is an attractive method for obtaining molecular assemblies owing to their facile fabrication process in aqueous media, but more insights are required in order to control the higher-dimensional structures of polypeptide-based PICs. Herein, the PIC formation behavior of oppositely charged homochiral polypeptides, poly-L-lysine and poly(ethylene glycol)-b-poly(L-glutamate) (PEG-PLG), and their secondary structures are carefully studied in water. PIC formation takes place in a polymer concentration-dependent manner, and clear beta-sheet formation is observed at polymer concentrations >= 0.3 mg mL(-1). The results also confirm that multimolecular aggregation is a prerequisite for beta-sheet formation, which indicates that the inner hydrophobic environment of PICs is favorable for beta-sheet formation. Furthermore, the PEG weight fraction, stereoregularity of the polypeptide, and ionic strength of the solutions are found to be key factors for generating a secondary structure, presumably because these factors can contribute to the tuning of the inner environment of PICs. This method of producing water-soluble nanoassemblies from oppositely charged polypeptides may expedite self-assembly studies in biological systems and be incorporated into various molecular systems to exploit protein-mimicking features.

DOI： 10.1002/marc.201500368

Language：English   Publishing type：Research paper (other academic)  

Microchannel-assisted preparation of polyion complex vesicles and real-time observation of their dynamic responses to external electric fields

Language：Japanese  

Development of SPIO-loaded Unilamellar Polyion Complex Vesicles (SPIO-Cy5-PICsomes) as a High Relaxivity Contrast Agent for Early-stage Tumor Detection

Language：English   Publishing type：Research paper (scientific journal)  

Integrating catalytic functions into polymeric vesicles through enzyme entrapment is appealing for bioreactor fabrication, yet there are critical issues regarding the regulation of solute transport through membranes and enzyme loading without denaturation. Polyion complex vesicles (PICsomes) with semipermeable membranes and the propensity to form in water can overcome these issues; however, cross-linking is required for sufficient physiological stability. Herein, we report the first successful fabrication of non-cross-linked PICsomes with sufficient stability at physiological salinity and temperature by tuning the hydrophobicity of the aliphatic side chains in the pendant group of the constituent polyelectrolytes. Dynamic light scattering and transmission electron microscopy revealed that the intervesicular fusion and disintegration of the PICsomes was prevented and a narrow distribution was maintained at physiological salinity and temperatures. Furthermore, their application as enzymatic nanoreactors was verified even in the presence of proteases. As such, the potential utility of the PICsomes in biomedical fields was established.

DOI： 10.1021/bm500127g

Language：English  

Nano-scaled devices are a promising platform for specific detection of pathological targets, facilitating the analysis of biological tissues in real-time, while improving the diagnostic approaches and the efficacy of therapies. Herein, we review nanodevice approaches, including liposomes, nanoparticles and polymeric nanoassemblies, such as polymeric micelles and vesicles, which can precisely control their structure and functions for specifically interacting with cells and tissues. These systems have been successfully used for the selective delivery of reporter and therapeutic agents to specific tissues with controlled cellular and subcellular targeting of biomolecules and programmed operation inside the body, suggesting a high potential for developing the analysis for nano-pathophysiology. (C) 2014 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.addr.2014.06.003

Language：English   Publishing type：Research paper (scientific journal)  

Polyion complexes (PICs) are attractive as eco-friendly materials, because they offer simple and fast preparation methods to exert various functionalities in aqueous medium. However, control of nanoarchitectures in PIC materials has not been fully realized, except for the case of micelles and unilamellar vesicles formed from block ionomers. Here, the procedure to control PIC nanoarchitectures with various morphologies was established for the first time by careful tuning in the composition of PICs made from PEG-based block-ionomers with a varying amount of homoionomers as additive to modulate the PEG weight fraction (f(PEG)) in the obtained PICs. Accordingly, the variation in f(PEG) from 12.1% to 6.5% induced vigorous transition in the microphase separated structures of PICs basically from micelle to lamella via cylindrical network. Notably, uniformed lamella with alternative layers of PEG and PIG domains was found at elevated temperature (70 degrees C), which, by lowering temperature, reversibly transformed to cylindrical P1C network apparently with connected aqueous channel in mesoscopic scale.

DOI： 10.1021/ma500314d

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/ma500314d

Language：English  

DOI： 10.1016/j.jconrel.2014.01.021

Language：English   Publishing type：Research paper (scientific journal)  

Much attention has been devoted to precise control of the size and morphology in nanosized molecular assemblies for a wide range of materials applications. Recently, we reported observing submicron/nanosized polyion complex vesicles (Nano-PICsomes) with a narrow size distribution, synthesized using specific types of homocatiomers and polyethylene glycol (PEG)-based block aniomers. However, only one example of Nano-PICsomes has been reported to date. Here, the role of the chemical composition of PEG-based block aniomers and the chemical structures of the side chains of homocatiomers were carefully examined to better understand the formation of Nano-PICsomes. Transmission electron microscopy and dynamic light scattering analyses of Nano-PICsomes revealed that a longer length of ionic segments in the block aniomers or a PEG weight fraction (f(PEG)) <10&#37;, is required for the selective formation of Nano-PICsomes, whereas polymer combinations with f(PEG) >10&#37; produced spherical micelles. In addition, the homocatiomers containing longer aliphatic side chains (e. g., five or six carbon atoms) favored the formation of Nano-PICsomes, whereas those containing shorter aliphatic side chains produced irregularly shaped PIC micelles. Accordingly, f(PEG) and the length of the side chain were found to be the key factors that control the morphologies of Nano-PICsomes. Insights gained from this study can broaden the spectrum of the design of Nano-PICsomes for use in a diverse range of material applications.

DOI： 10.1038/pj.2013.82

Language：English   Publishing type：Research paper (scientific journal)  

Polymer vesicles formed by a pair of oppositely charged poly(ethylene glycol) (PEG)-based block aniomer and homocatiomer, termed "PICsomes", have tunable size, and are characterized by unique semipermeable property due to the flexible and tunable hydrophilicity of polyion complex (PIC) membranes. The PICsomes can encapsulate a variety of molecules in an inner aqueous phase just by a simple vortex mixing of solution, expecting their utility as nanocontainers of substances with biomedical interests. Here, we report on a new functionality of the PICsomes: photoinduced release of photoactive agents for intracellular drug delivery. A potent photosensitizer, Al(III) phthalocyanine chloride disulfonic acid (AlPcS2a), was efficiently incorporated into the PICsomes (11&#37;(w/w)), and its quick release was induced by photoirracliation possibly due to the photochemical damage of the PIG membranes. The combination of a high-resolution fluorescent confocal microscopy and a lysosome membrane-specific staining method revealed that such photoinduced release of AlPcS2a occurred even in the lysosomes of living cells after endocytic internalization. Simultaneously, the released AlPcS2a photochemically affected the integrity of the lysosomal membranes, leading to the translocation of AlPcS2a and PICsomes themselves to the cytoplasm. Consequently, the AlPcS2a-encapsulated PICsomes (AIPcS2a-PICsomes) exhibited appreciably stronger photocytotoxicity compared with free AlPcS2a alone. Thus, the AlPcS2a-PICsomes have promising feasibility for the photodynamic therapy or the photoinduced cytoplasmic delivery of therapeutic molecules.

DOI： 10.1021/ja406992w

Language：English   Publishing type：Research paper (scientific journal)  

Polyion complex (PIC) formation is one of the most powerful techniques for obtaining molecular self-assemblies in aqueous media. The simple preparation process based on multiple electrostatic interactions is quite attractive for material syntheses, as well as biomedical applications. Therefore, it is desirable to control PIC architectures at the nanoscale in order to expand the scope of PIC materials. In this review article, recent progress on PIC vesicles (PICsomes) is summarized. PICsomes were first developed by my research group, and we recently succeeded in controlling the sizes and structural uniformity of the vesicles. Furthermore, the characteristic dynamic nature of PICs was revealed: PICs were found to exhibit reversible association/dissociation and structural transformation. We demonstrated that crosslinking the PIC layers of PICsomes is a powerful method for tuning properties such as stability and permeability. Finally, the potential utility of PICsomes for drug delivery nanocarriers was examined, and their future biomedical application is discussed.

DOI： 10.1038/pj.2013.33

Language：English   Publishing type：Research paper (scientific journal)  

Size controllable polyion complex vesicles (PICsomes), composed of biocompatible poly(ethylene glycol) (PEG) and poly(amino acid) s, have an extremely prolonged lifetime in the bloodstream that enables them to accumulate effectively in tumors via the enhanced permeability and retention (EPR) effect. The purpose of this study was to use PICsomes to synthesize a highly sensitive MRI contrast agent for more precise tumor detection. We synthesized SPIO-Cy5-PICsomes (superparamagnetic iron oxide nanoparticle-loaded Cy5-cross-linked Nano-PICsomes) and characterized them using dynamic light scattering and transmission electron microscopy in vitro and evaluated their ability to detect subcutaneously grafted tumors in vivo with MRI. The transverse relaxivity (r(2)) of the SPIO-Cy5-PICsomes (r(2) = 663 +/- 28 mM(-1) s(-1)) was 2.54 times higher than that of bare clinically-used SPIO. In in vivo MRI experiments on mice subcutaneously grafted with colon-26 tumor cells, the tumor signal was significantly altered at 3 h after SPIO-Cy5-PICsome administration and persisted for at least 24 h. Small and early-stage in vivo tumors (3 days after grafting, approximately 4 mm(3)) were also clearly detected with MRI. SPIO-loaded PICsomes are sensitive MRI contrast agents that can act as a powerful nanocarrier to detect small tumors for early diagnosis. (C) 2013 Elsevier B. V. All rights reserved.

DOI： 10.1016/j.jconrel.2013.03.016

Language：English   Publishing type：Research paper (international conference proceedings)  

Characterization of nanoparticle permeability on a membrane-integrated microfluidic device

Language：English   Publishing type：Research paper (scientific journal)  

Although hollow microscopic capsules have a variety of potential biomedical applications, reports of organic-solvent-free methods for their preparation are rather limited. Herein, a novel approach is demonstrated for organic-solvent-free preparation of giant unilamellar vesicles utilizing the unique response of polyion complexes (PICs) to changes in additive salt concentration. A microfluidic device consisting of a main channel bearing side pockets that work as microscale reaction chambers is designed for facilitating the preparation process under an optical microscope. With this device, real-time observation of morphological transformation of individual PIC microparticles is carried out during rapid reduction of the additive salt concentration and direct formation of giant vesicles from PIC microparticles is shown. There is a quasilinear relationship between the surface areas of the formed vesicles and the volumes of the PIC microparticles, and the thickness of the vesicle membrane estimated by the relationship is indicative of the formation of a uniform unilamellar structure of the PIC membrane. Furthermore, detailed properties of the formed PIC vesicles with regard to salt response, loading of guest molecules, and permeability of the PIC membrane with/without modification of the PIC membrane by cross-linking are investigated using the microfluidic chamber. Thus, the usefulness of the microfluidic chamber for visualization and investigation of dynamic responses of microscale soft materials during changes in surrounding conditions is also demonstrated.

DOI： 10.1039/c3sm00089c

Language：English   Publishing type：Research paper (scientific journal)  

Understanding the dynamic behavior of molecular self-assemblies with higher-dimensional structures remains a key challenge to obtaining well-controlled and monodispersed structures. Nonetheless, there exist few systems capable of realizing the mechanism of supramolecular polymerization at higher dimensions. Herein, we report the unique self-assembling behavior of polyion complexes (PICs) consisting of poly(ethylene glycol)-polyelectrolyte block copolymer as an example of two-dimensional supramolecular living polymerization. Monodispersed and submicrometer unilamellar PIC vesicles (nano-PICsomes) displayed time-dependent growth while maintaining a narrow size distribution and a unilamellar structure. Detailed analysis of the system revealed that vesicle growth proceeded through the consumption of unit PICs (uPICs) composed of a single polycation/polyanion pair and was able to restart upon the further addition of isolated uPICs. Interestingly, the resulting vesicles underwent dissociation into uPICs in response to mechanical stress. These results clearly frame the growth as a two-dimensional supramolecular living polymerization of uPICs.

DOI： 10.1021/ja3096587

Language：English   Publishing type：Research paper (scientific journal)  

Spontaneous formation of polymeric metallosomes with uniform size (similar to 100 nm) was found to occur in aqueous medium through the reaction of an anticancer agent, (1,2-diaminocyclohexane)platinum(II) (DACHPt), with a Y-shaped block copolymer of omega-cholesteroyl-poly(L-glutamic acid) and two-armed poly(ethylene glycol) (PEGasus-PLGA-Chole). Circular dichroism spectrum measurements revealed that the PLGA segment forms an alpha-helix structure within the metallosomes, suggesting that secondary-structure formation of metallocomplexed PLGA segment may drive the self-assembly of the system into vesicular structure. These metallosomes can encapsulate water-soluble fluorescent macromolecules into their inner aqueous phase and eventually deliver them selectively into tumor tissues in mice, owing to the prolonged blood circulation. Accordingly, fluorescent imaging of the tumor was successfully demonstrated along with an appreciable antitumor activity by DACHPt moieties retained in the vesicular wall of the metallosomes, indicating the potential of metallosomes as multifunctional drug carriers.

DOI： 10.1021/ja304615y

Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

DOI： 10.20665/kakyoshi.59.11_550

Language：English   Publishing type：Research paper (scientific journal)  

Selective disposition of nanocarriers into target tissue is an essential issue in drug delivery. Critical size of nanocarriers (∼150 nm) discriminating the permeability into normal and tumor tissues was determined by the use of size-tunable, polyion complex hollow vesicles (PICsome) as a ruler.

DOI： 10.1039/c1cc11465d

Language：English   Publishing type：Research paper (scientific journal)  

Fabrication of monodispersed, submicrometer-sized vesicles (nanosomes) that form through self-assembly possessing a thin and permeable membrane remains a significant challenge. Conventional fabrication of nanosomes through self-assembly of amphiphilic molecules often requires cumbersome processes using organic solvents combined with physical procedures (e.g., sonication, thermal treatment, and membrane filtration) to obtain unilamellar structures with a controlled size distribution. Herein, we report the first example of spontaneously formed submicrometer-sized unilamellar polyion complex vesicles (Nano-PICsomes) via self-assembly of a pair of oppositely charged PEG block aniomer and homocatiomer in an aqueous medium. Detailed dynamic light scattering and transmission electron microscopic analysis revealed that vesicle sizes can be controlled in the range of 100-400 nm with a narrow size distribution, simply by changing the total polymer concentration. Also, each Nano-PICsome was composed of a uniform single PIC membrane, the thickness of which is around 10-15 nm, regardless of its size. Fluorescence correlation spectroscopy measurement verified that Nano-PICsomes were able to encapsulate water-soluble fluorescent macromolecules in the inner water phase and release them slowly into the exterior. Moreover, cross-linking of the vesicle membrane allows tuning of permeability, enhancement in stability under physiological conditions, and preservation of size and structure even after freeze-drying and centrifugation treatment. Finally, Nano-PICsomes showed a long circulation time in the bloodstream of mice. Precise control of the particle size and structure of hollow capsules through simple aqueous self-assembly and easy modification of their properties by cross-linking is quite novel and fascinating in terms of ecological, low-cost, and low-energy fabrication processes as well as the potential utility in the biomedical arena.

DOI： 10.1021/ja908350e

Language：English   Publishing type：Research paper (scientific journal)  

Water pump: Polyion complex (PIC) vesicles are spontaneously formed from PIC microdroplets, which are formed by mixing cationic and anionic polymers (see picture). The formation process can be reversibly controlled by local heating with a focused infrared laser that triggers microphase separation and subsequent water influx. The size of the resulting giant unilamellar vesicles is determined by the initial size of the PIC droplets.

DOI： 10.1002/anie.200900721

Language：English   Publishing type：Research paper (scientific journal)  

In this communication, a novel "self-templating" strategy was used to prepare uniform and biocompatible nanocapsules by the addition of a reduction agent (i.e., DTT) into a solution of highly monodispersed PICmicelles bearing a heterodetachable PEG Corona. PEG chains were released from PICmicelle shells following disulfide reduction which leads a spontaneous and drastic morphology evolution from micelles to vesicles induced by the decrease of the PEG weight fraction. Formation of uniform nanocapsules with controllable capsule size was achieved by careful control of the micelle composition and molecular weight of homo-P[Asp(DET)].

DOI： 10.1021/ja808419b

Language：English   Publishing type：Research paper (scientific journal)  

The acidic pH-sensitivity of polyion complex vesicles (PICsomes) was investigated, using dynamic light scattering (DLS) and confocal laser scanning microscopy (CLSM). PICsomes showed pH-dependent and reversible structural transition, and also underwent a change in permeability by sensing acidic pH. Increased membrane permeability at the pH corresponding to cellular endosomes may be useful for future applications of PICsomes as a delivery vehicle of biologically active compounds to intracellular compartment.

DOI： 10.1039/b815884c

Language：English   Publishing type：Research paper (scientific journal)  

(Figure Presented) Take your PIC: Biologically active polyion complex vesicles (PICsomes) with encapsulated myoglobin (Mb) can be prepared by the self-assembly of a pair of oppositely charged block ionomers with polyethylene glycol (PEG) segments (see picture; metMb: metmyoglobin). The loaded Mb maintains reversible oxygenation even in the presence of trypsin.

DOI： 10.1002/anie.200701776

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/ja057993r

Language：English   Publishing type：Research paper (scientific journal)  

Rewritable phosphorescent paper by the control of competing kinetic and thermodynamic self-assembling events

DOI： 10.1038/nmat1401

Language：English   Publishing type：Research paper (scientific journal)  

Phosphorescent organogels via "metallophilic" interactions for reversible RGB-color switching
A trinuclear Au(l) pyrazolate complex bearing long alkyl chains (1) in hexane self-assembles via a Au(l)-Au(I) metallophilic interaction, to form a red-luminescent organogel (lambda(em) = 640 nm, lambda(ext) = 284 nm). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis of an air-dried gel with 1 show the presence of heavily entangled fibers, each consisting of a rectangularly packed columnar assembly of 1. Doping of the organogel with a small amount of Ag(+) results in a blue luminescence (lambda(em) = 458 rim, lambda(ext) = 370 nm) without disruption of the gel, while removal of doped Ag+ with cetyltrimethylammonium chloride results in complete recovery of the original red-luminescent gel. Upon heating, these organogels undergo gel-to-sol transition due to the destabilization of the metallophilic interactions, where the red luminescence of the nondoped system becomes hardly visible, while the blue luminescence of the Ag(+)-doped system turns green (lambda(em) = 501 nm, lambda(ext) = 370 nm). On cooling, these solutions undergo gelation and synchronously recover the original luminescences. The observed RGB (red-green-blue) luminescences are all long-lived (3-6 mus) and assigned to electronic transitions from triplet-excited states.

DOI： 10.1021/ja0441007

Language：English   Publisher：Anticancer Research  

Background/Aim: Chimeric antigen receptor T‑cell therapy has shown efficacy against chemoresistant B‑cell leukemia and lymphoma but is limited in solid tumors. This study proposes using inflammation‑triggering engineered macrophages (MacTriggers) to target chemoresistant tumors. Intravenous MacTriggers infiltrate tumors, inducing inflammation via tumor necrosis factor‑alpha (TNF‑α), converting the immunosuppressive microenvironment into an immuno‑active state, and enhancing anti‑tumor immune responses. Materials and Methods: DOX‑resistant murine colon cancer cells (DOX‑Resi) were established by repeated in vivo exposure to DOX. IC50 values and mRNA expression of Abcb1a (encoding P‑gp) in WT or DOX‑Resi cells were evaluated by qPCR. MacTriggers were engineered to release TNF‑α upon sensing tumor‑associated arginase 1 (Arg1) activity. BALB/c mice with subcutaneous DOX‑Resi tumors received intravenous MacTriggers or DOX. Tumor growth, histological changes, and side effects, including cardiotoxicity, were assessed via tumor volume monitoring, immunohistochemistry, and serum cardiac troponin‑I measurement. Results: DOX‑Resi cells had an IC50 value approximately 2.5 times higher than WT cells, with significantly higher Abcb1a expression. MacTriggers significantly suppressed DOX‑Resi tumor growth, while DOX showed limited efficacy. MacTrigger administration did not cause severe side effects, unlike DOX, which induced cardiotoxicity. Conclusion: MacTriggers offer a novel, effective, and safer therapeutic approach for chemoresistant solid tumors, addressing chemotherapy limitations and improving outcomes in drug‑resistant cancers.

DOI： 10.21873/anticanres.17525

Scopus

PubMed

Language：English   Publisher：Analytical Sciences  

Liquid–liquid phase separation leads to the formation of liquid droplets (LqDs) such as P granules in Caenorhabditis elegans (C. elegans). In this study, we demonstrate the label-free visualization of LqDs using multimodal nonlinear optical imaging both in vitro and in vivo. In vitro measurements with polymerized adenine [poly(A)], we found significantly higher poly(A) concentrations in LqDs compared to surrounding solutions, with the limit of detection (LoD) of 32 mg/mL. In vivo measurements, we performed label-free imaging of C. elegans. Despite efforts to detect P granules within P lineage cells in both wild-type C. elegans and green fluorescent protein (GFP)-tagged strains, no clear RNA-specific signals were observed. This indicates that the RNA concentration in P granules is lower than anticipated and falls below our in vitro LoD. These results underscore the challenges of label-free RNA detection in P granules.

DOI： 10.1007/s44211-025-00747-3

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Publisher：Scientometrics  

Researchers play a pivotal role as key actors in science communication. Therefore, it is imperative for academic institutions to support their activities. However, there are many uncertainties regarding activities by researcher and institutional support. Notably, researchers’ awareness and experience of these activities need to be clarified. Therefore, we conducted a questionnaire survey on researchers at Kyushu University in Japan to assess their awareness of and willingness to participate in science communication activities. The survey was conducted between 2021 and 2022. We sent a questionnaire to 2,336 researchers and received responses from 577 (24.7%). The survey revealed that the awareness of science communication was not very high (43%). Remarkably, awareness among medical, dental, and pharmaceutical researchers was relatively low. However, all field researchers recognized the importance of the activities and had a strong willingness to participate if given the opportunity. Furthermore, the results show that researchers in the humanities and social sciences had a relatively high awareness of promoting science communication in Japanese Science, Technology, and Innovation policy. Researchers over 40 years of age had more experience than researchers aged 20–39 years. Barriers such as time constraints and lack of regulation of personnel evaluation were reaffirmed.

DOI： 10.1007/s11192-025-05251-z

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Purpose: Inhibitors of the calciprotein particle (CPP) maturation have been developed so far as therapeutics for vascular calcification. However, the short blood half-life limited their application. Here we designed the conjugate of a CPP maturation inhibitor, alendronate (ALN) with human serum albumin (HSA) to utilize the long blood retention nature of HSA. Method: The HSA-ALN conjugates with different modification numbers of ALN per HSA were prepared. The inhibitory effect of the conjugates on the CPP maturation was evaluated using a reported cell-free system as a time of conversion from CPPI to CPPII. The CPP binding of fluorescent-labeled conjugates was carried out using flow cytometry. The plasma half-life of the conjugates was evaluated in mice after intravenous injection. Results: We found that the HSA-ALN conjugates bound to CPP via the specific interaction between ALN and calcium phosphate of CPP. As a result, the conjugates showed a much higher inhibition effect of CPP maturation than those of free ALN and intact HSA. A modification ratio of two ALN molecules per HSA was found to be significant enough to inhibit the CPP maturation. Such a small modification ratio minimized the impact on the long blood retention nature of HSA. Conclusion: This study showed that HSA-ALN conjugates not only have superior CPP growth inhibition effects but also possess significantly higher blood half-lives compared to those of free ALN. These findings suggest that HSA-ALN conjugates are promising therapeutics for vascular calcification associated with the deposition of CPP.

DOI： 10.1007/s12247-024-09910-1

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Language：English   Publisher：ACS Medicinal Chemistry Letters  

We proposed a novel ligand for the interaction with human serum albumin (HSA) to extend the blood half-life of small molecular weight therapeutics. The ligand features an alkyl chain and an activated disulfide to allow binding to the hydrophobic pockets of HSA and the formation of disulfide to Cys34 of HSA, thereby minimizing the initial renal clearance. The dual nature of the ligand-HSA bonding was expected to give the ligand long blood retention. After 1 min of mixing with HSA, the ligand showed higher binding (1.7 times) than that of a control ligand (containing only activated disulfide). After intravenous injection to mice, the ligand half-lives were 1.6 and 9.2 times longer than those of control ligands with the active disulfide alone and with the alkyl chain alone, respectively. The proposed ligand has the potential to act as a platform for extending the half-life of small therapeutics in vivo.

DOI： 10.1021/acsmedchemlett.4c00503

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Background: We have previously reported engineered macrophages (MacTriggers) that can accelerate the release of tumor necrosis factor-α in response to M2 polarization. MacTriggers are characterized by two original characteristics of macrophages: (1) migration to tumors; and (2) polarization to the M2 phenotype in tumors. Intravenously administered MacTriggers efficiently accumulated in the tumors and induced tumor-specific inflammation. This study reports a novel methodology for enhancing the anti-tumor effects of immune checkpoint inhibitors (ICIs). Results: In this study, we newly found that the intravenously administered MacTriggers in BALB/c mouse models upregulated the expression levels of immune checkpoint proteins, such as programmed cell death (PD)-1 in CD8+ T cells and PD-ligand 1 (PD-L1) in cancer cells and macrophages. Consequently, in two ICI-resistant tumor-inoculated mouse models, the combined administration of MacTrigger and anti-PD-1 antibody (aPD-1) synergistically inhibited tumor growth, whereas monotherapy with aPD-1 did not exhibit anti-tumor effects. This synergistic effect was mainly from aPD-1 enhancing the tumor-attacking ability of CD8+ T cells, which could infiltrate into the tumors following MacTrigger treatment. Importantly, no side effects were observed in normal tissues, particularly in the liver and spleen, indicating that the MacTriggers did not enhance the aPD-1 reactivity in normal tissues. This specificity was from the MacTriggers not polarizing to the M2 phenotype in normal tissues, thereby avoiding inflammation and increased PD-1/PD-L1 expression. MacTriggers could enhance aPD-1 reactivity only in tumors following tumor-specific inflammation induction. Conclusions: Our findings suggest that the MacTrigger and aPD-1 combination therapy is a novel approach for potentially overcoming the current low ICI response rates while avoiding side effects.

DOI： 10.3390/cancers16223787

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Pharmaceutics  

Background: Acrylamide polymers with zwitterionic carboxybetaine (CB) side groups have attracted attention as stealth polymers that do not induce antibodies when conjugated to proteins. However, they induce antibodies when modified onto liposomes. We hypothesized that antibodies are produced against polymer backbones rather than CB side groups. Objectives: In this study, we designed and synthesized a polymer employing CB in its main chain, poly(N-acetic acid-N-methyl-propyleneimine) (PAMPI), and evaluated the blood retention of PAMPI-modified liposomes in mice. Results: The non-fouling nature of PAMPI-modified liposomes estimated from serum protein adsorption was found to be not inferior to PCB- and PEG-modified liposomes. However, to our surprise, the PAMPI-modified liposomes showed an instantaneous clearance less than 1 h post-injection, comparable to the naked liposomes. Conclusions: The extent of the blood retention of polymer-modified liposomes cannot be predicted by their susceptibility to serum protein adsorption and semi-flexible conformation.

DOI： 10.3390/pharmaceutics16101271

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Language：English   Publisher：(公社)日本分析化学会  

イリノテカン(CPT-11)の代謝物であるSN-38のα-ラムノース(Rham)結合プロドラッグ(Rham-SN-38)について検討した。Rham-SN-38の酵素反応を調べ、細胞毒性について検討した。α-ラムノシダーゼ(Rdase)を介したSN-38の放出は2時間以内に完了し、kcat/Km値はCPT-11の約5.0×104倍であった。Rham-SN-38が3種類の癌細胞と1種類の正常細胞に及ぼす50%阻害濃度(IC50)は4.5×103nMを超え、Rdase添加により細胞毒性が増加し、IC50値は遊離SN-38と同等であった。Rdaseの有無による細胞毒性の差の指標であるQIC50値は、約1.0×102倍を超えていた。以上より、Rham-SN-38は癌治療のプロドラッグとして有用であると考えられた。

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

We report that novel protein-based Fc-binding antibody recruiting molecules (Fc-ARMs) with HER2-specific affibodies induce ADCC, but are less effective than conventional IgG-mediated ADCC and require further affinity improvement.

DOI： 10.1039/d4ra03391d

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

This study introduces the α-rhamnose (Rham)-conjugated prodrug of SN-38 (Rham-SN-38) as a promising alternative to irinotecan. α-rhamnosidase, responsible for SN-38 release from Rham-SN-38, does not express in human cells, minimizing individual variability and side effects. The injection of the α-rhamnosidase into the tumor tissues makes it possible, for the first time, to activate the Rham-SN-38. Furthermore, α-rhamnosidase demonstrates significantly higher activity than carboxylesterase, the specific enzyme activating irinotecan. SN-38 release mediated by α-rhamnosidase completes within 2 h, with a kcat/Km value approximately 5.0 × 104-fold higher than that of irinotecan. The 50% inhibition concentration (IC50) of Rham-SN-38 against three types of cancer cells and one normal cell exceeds 4.5 × 103 nM. The addition of α-rhamnosidase significantly increases cytotoxicity, with IC50 comparable to free SN-38. The QIC50, an index reflecting the difference in cytotoxicity with and without α-rhamnosidase, exceeds approximately 1.0 × 102-fold. Rham-SN-38, synthesized in this study, demonstrates significant potential as a prodrug for cancer therapy. Graphical abstract: (Figure presented.)

DOI： 10.1007/s44211-024-00593-9

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press (OUP)  

Abstract

Polyion complex vesicles (PICsomes) possess several features that render them as suitable for drug delivery systems. However, retaining water-soluble low-molecular-weight compounds (WLMWCs) remains challenging because of the high permeability of their vesicular membranes. Herein, we propose a new approach for prolonged retention and sustained release of WLMWCs from PICsomes by loading hydroxypropyl methylcellulose to increase the viscosity of the inner aqueous phase. The PICsomes retained 2% to 4% of the WLMWCs, and 100% of the WLMWCs were released within 96 h according to first-order kinetics.

DOI： 10.1093/chemle/upae070

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Publishing type：Research paper (scientific journal)   Publisher：MYU K.K.  

Human orthogonal enzymes (HOEs) do not show the same activities as the endogenous enzymes of human cells and thus are useful as amplification enzymes to detect antigen proteins in biological samples. Here, we evaluate a new HOE from Escherichia coli, α-sulfoquinovosidase (α-SQase). We confirmed that the activity of α-SQase did not exist in examined human cell lines, and thus it was applicable to live-cell enzyme-linked immunosorbent assay (ELISA) in which the antigen membrane protein on cells was detected without inactivating endogenous enzymes, a pretreatment required for cell ELISA using conventional amplification enzymes. Here, we also developed a fluorescent substrate for α-SQase whose active residue is located at the end of the narrow, deep pocket of the substrate recognition site. The designed methylumbelliferyl substrate with a hydroxyl benzyl alcohol linker showed a similar reactivity to the p-nitrophenol substrate, a good substrate for α-SQase.

DOI： 10.18494/SAM4816

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Language：Japanese   Publisher：THE MEMBRANE SOCIETY OF JAPAN  

Electrostatic interactions play an important role in various biological events. This article focuses on polyion complex (PIC) materials, which are formed by utilizing electrostatic interactions, and overviews the development of their functions as biomaterials and the new strategies for biomacromolecular assembly formation based on the rational control of electrostatic interactions. Particularly, PIC vesicles (PICsomes), which are membrane–based architectures, and coacervates, which are artificial biomolecular condensates, are highlighted. The utilization of their dynamic properties is discussed, as well as a novel method for preparing hierarchical structures utilizing self-assembled membranes for compartmentalization.

DOI： 10.5360/membrane.49.337

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Language：Japanese   Publisher：Japan Science Support Foundation  

DOI： 10.5363/tits.28.5_62

CiNii Research

Language：English   Publisher：(公社)日本分析化学会  

ポリプロピレンイミン(PPI)のトランスフェクション(TF)能を、標準的TF試薬であるポリエチレンイミン(PEI)と比較した。この検討により、PPIはPEIよりもエンドソームpHに対する応答性が良く、PPIのエンドソームエスケープ能が有望であることが示された。PPIはPEIに比べてプラスミドDNAの縮合能が高く、疎水性の高さに起因すると考えられた。PPIの細胞毒性はPEIより幾分高いものの、細胞株によってはPPIのTF効率がPEIと同等か、PEIよりも高かった。これらの結果から、PPIは細胞の種類によってPEIより効率の良い代替的TF試薬になりうると考えられた。

Language：English   Publisher：Royal Society of Chemistry (RSC)  

This study presents a simple strategy for the sequestration of globular proteins as clients into synthetic polypeptide-based complex coacervates as a scaffold, thereby recapitulating the scaffold-client interaction found in biological condensates. Considering the low net charges of scaffold proteins participating in biological condensates, the linear charge density (σ) on the polyanion, polyethylene glycol-b-poly(aspartic acids), was reduced by introducing hydroxypropyl or butyl moieties as a charge-neutral pendant group. Complex coacervate prepared from the series of reduced-σ polyanions and the polycation, homo-poly-L-lysine, could act as a scaffold that sequestered various globular proteins with high encapsulation efficiency (>80%), which sometimes involved further agglomerations in the coacervates. The sequestration of proteins was basically driven by electrostatic interaction, and therefore depended on the ionic strength and charges of the proteins. However, based on the results of polymer partitioning in the coacervate in the presence or absence of proteins, charge ratios between cationic and anionic polymers were maintained at the charge ratio of unity. Therefore, the origin of the electrostatic interaction with proteins is considered to be dynamic frustrated charges in the complex coacervates created by non-neutralized charges on polymer chains. Furthermore, fluorescence recovery after photobleaching (FRAP) measurements showed that the interaction of side-chains and proteins changed the dynamic property of coacervates. It also suggested that the physical properties of the condensate are tunable before and after the sequestration of globular proteins. The present rational design approach of the scaffold-client interaction is helpful for basic life-science research and the applied frontier of artificial organelles.

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

Enzymes are used to amplify signals for detection of antigen proteins in biological samples. However, the enzymes conventionally used for this purpose have limitations, such as the presence of the...

DOI： 10.1039/d3an00314k

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

Herein, we report engineered macrophages, termed “MacTrigger,” acting as a trigger to induce an inflammatory environment only in tumor tissues. This led to intensive anti-tumor effects based on the removal potential of foreign substances. The strength of this study is the utilization of two unique functions of macrophages: (1) their ability to migrate to tumor tissues and (2) polarization into the anti-inflammatory M2 phenotype in the presence of tumor tissues. The MacTrigger accelerated the release of inflammatory cytokines, tumor necrosis factor-alpha (TNF-α), when it was polarized to the M2 phenotype. When the MacTrigger was administered to tumor-bearing mice, tumor growth was significantly inhibited compared with the non-treatment group, the un-transfected macrophages group, and the group with engineered macrophages capable of randomly releasing TNF-α. Additionally, the ratio of the M1 phenotype to the M2 phenotype in tumor tissues was >1 only in the MacTrigger group. Moreover, the ratios of natural killer cells and CD8+T cells in tumor tissues were increased compared with other groups. These results indicate that MacTrigger can induce inflammation in tumor tissues, leading to effective anti-tumor effects. In normal tissues, especially the liver, notable side effects were not observed. This is because, in the liver, the MacTrigger was not polarized to the M2 phenotype and could not induce inflammation. These results suggest that the MacTrigger is a “trigger” that can induce inflammation only in tumor tissues, then allowing the body to attack tumor tissues through the innate immunity system.

DOI： 10.1016/j.jconrel.2023.04.010

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Polypropyleneimine (PPI) was examined as a transfection reagent comparing with most widely used polymer, polyethyleneimine (PEI). PPI had better responsiveness to the endosomal pH and showed more condensation ability of plasmid DNA than PEI. Although the cytotoxicity of PPI was somewhat higher than PEI, the transfection efficacy of PPI was comparable with PEI or higher than PEI in some cell line. Thus, PPI would be an alternative transfection reagent. Graphical abstract: [Figure not available: see fulltext.].

DOI： 10.1007/s44211-023-00284-x

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Other Link： https://link.springer.com/article/10.1007/s44211-023-00284-x/fulltext.html

Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI  

Mesoscopic-sized polyion complex vesicles (PICsomes) with semi-permeable membranes are promising nanoreactors for enzyme prodrug therapy (EPT), mainly due to their ability to accommodate enzymes in their inner cavity. Increased loading efficacy and retained activity of enzymes in PICsomes are crucial for their practical application. Herein, a novel preparation method for enzyme-loaded PICsomes, the stepwise crosslinking (SWCL) method, was developed to achieve both high feed-to-loading enzyme efficiency and high enzymatic activity under in vivo conditions. Cytosine deaminase (CD), which catalyzes the conversion of the 5-fluorocytosine (5-FC) prodrug to cytotoxic 5-fluorouracil (5-FU), was loaded into PICsomes. The SWCL strategy enabled a substantial increase in CD encapsulation efficiency, up to similar to 44% of the feeding amount. CD-loaded PICsomes (CD@PICsomes) showed prolonged blood circulation to achieve appreciable tumor accumulation via enhanced permeability and retention effect. The combination of CD@PICsomes and 5-FC produced superior antitumor activity in a subcutaneous model of C26 murine colon adenocarcinoma, even at a lower dose than systemic 5-FU treatment, and showed significantly reduced adverse effects. These results reveal the feasibility of PICsome-based EPT as a novel, highly efficient, and safe cancer treatment modality.

DOI： 10.3390/polym15061368

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DOI： https://doi.org/10.3390/ijerph192316260

Language：English   Publisher：International Journal of Environmental Research and Public Health  

This study aimed to investigate the association between dietary problems and frailty according to tooth loss in older Japanese people. This cross-sectional study included 160 older people (mean age 82.6 years) from Japan. Frailty status was assessed using the Study of Osteoporotic Fractures (SOF) criteria, which consists of (i) weight loss > 5% in the past year, (ii) inability to perform five chair stands, and (iii) self-perceived reduced energy level. Frailty was defined as the presence of ≥2 items of SOF criteria. Multivariate logistic regression analyses were performed with frailty as the dependent variable and dietary problems as the independent variable, stratified according to having <20 teeth. Low appetite and no enjoyment of eating were associated with frailty after adjusting for covariates in participants with <20 teeth. Dietary problems, including low appetite, eating alone, and negative attitudes toward enjoyment of eating were associated with a self-perceived reduced energy level in participants with <20 teeth. However, this association was not observed in participants with ≥20 teeth. In older people with fewer teeth, dietary problems have been suggested to be associated with frailty. Therefore, it may be necessary to pay attention to dietary problems, especially in older people with tooth loss.

DOI： 10.3390/ijerph192316260

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Publisher：Chemistry Letters  

Polynucleotide-loaded nanoparticles are potentially useful for the regulation of intracellular nucleotide levels. Polyadenylic acid and polyguanylic acid were used as model compounds for encapsulation into poly(lactic-co-glycolic acid) nanoparticles. The properties of the produced nanoparticles, as well as the effect of the polynucleotide molecular size on encapsulation into the nanoparticles were investigated.

DOI： 10.1246/cl.220318

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Language：Japanese   Publisher：Japan Science Support Foundation  

<p>　日本学術会議若手アカデミーの第24期の活動を振り返りつつ総括する。そこから未来へ向けて学術コミュニティに求められる態度について考えるとともに、第25期の活動への展望と期待を述べる。</p>

DOI： 10.5363/tits.27.6_46

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Language：Japanese   Publisher：THE JAPAN SOCIETY OF DRUG DELIVERY SYSTEM  

DOI： 10.2745/dds.37.185

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Language：Japanese   Publisher：THE JAPAN SOCIETY OF DRUG DELIVERY SYSTEM  

In the present article, we propose a new style of open innovation as an approach to solve unsolved issues “不（Fu）” of Japanese companies as well as societal issues in Japan （“Fu” of Japanese society） based on a backcasting approach. Also, we introduce the Open Science Platform promoted by Kyushu University as an practical example of such a new open innovation platform.

DOI： 10.2745/dds.37.45

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Language：English   Publishing type：Research paper (scientific journal)  

The fraction of antibiotics that are excreted from the intestine during administration leads to disruption of commensal bacteria as well as resulting in dysbiosis and various diseases. To protect the gut microbiota during treatment with antibiotics, use of activated carbon (AC) has recently been reported as a method to adsorb antibiotics. However, the antibiotic adsorption by AC is nonspecific and may also result in the adsorption of essential biological molecules. In this work, we reported that an anion exchange resin (AER) has better specificity than AC for adsorbing the β-lactam antibiotic cefoperazone (CEF). Because CEF has a negatively charged carboxylate group and a conjugated system, the AER was used to adsorb CEF through electrostatic and π-π interactions. The AER was specific for CEF over biological molecules such as bile acids and vitamins in the intestine. The AER protected Escherichia coli from CEF in vitro. Furthermore, oral administration of the AER reduced the fecal free CEF concentration, and protected the gut microbiota from CEF-induced dysbiosis.

DOI： 10.1039/d1bm00958c

Language：English   Publishing type：Research paper (scientific journal)  

Strategies that combine chemotherapies with unconventional agents such as nitric oxide (NO) have been shown to enhance cancer therapies. Compared with small molecule chemotherapy drugs, nanosized particles have improved therapeutic efficacies and reduced systemic side effects because of the enhanced permeability and retention effect. In this report, we prepared PEGylated liposomes (LP) that incorporated l-arginine (Arg) and the anticancer drug doxorubicin (Dox) to yield a co-delivery system (Dox-Arg-LP). On the basis of our previous research, we hypothesized that Dox-Arg-LP should achieve a synergistic anticancer effect because Arg conversion to NO by activated M1 macrophages augments the chemotherapeutic activity of Dox. Dox-Arg-LP showed comparable physical properties to those of conventional Dox-only liposomes (Dox-LP). In vitro assessment revealed that the cytotoxicity of Dox-Arg-LP toward cancer cells was significantly higher than that of Dox-LP. In vivo application of Dox-Arg-LP in mice enhanced the chemotherapeutic effect with a 2 mg kg-1 dose of Dox-Arg-LP achieving the same therapeutic efficacy as a two-fold higher dose of Dox-LP (i.e., 4 mg kg-1). Therefore, co-encapsulation of dual agents into a liposome formulation is an efficient strategy to enhance chemotherapy while reducing systemic toxicity.

DOI： 10.1039/d1ra06514a

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Here we proposed a-L-arabinofuranosidase from Clostridium thermocellum as an enzyme for signal amplification in bioanalysis whose activity does not exist in human cells. Combination of this enzyme and beta-galactosidase enabled simultaneous detection of two different antigens on live cells.

DOI： 10.1246/cl.210231

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The presence of intracellular signal transduction and its abnormal activities in many cancers has potential for medical and pharmaceutical applications. We recently developed a protein kinase C alpha (PKC alpha)-responsive gene carrier for cancerspecific gene delivery. Here, we demonstrate an in-depth analysis of cellular signal-responsive gene carrier and the impact of its selective transgene expression in response to malfunctioning intracellular signaling in cancer cells. We prepared a novel gene carrier consisting of a linear polyethylenimine (LPEI) main chain grafted to a cationic PKC alpha-specific substrate (FKKQGSFAKKK-NH2). The LPEI-peptide conjugate formed a nanosized polyplex with pDNA and mediated efficient cellular uptake and endosomal escape. This polyplex also led to successful transgene expression which responded to the target PKC alpha in various cancer cells and exhibited a 10-100-fold higher efficiency compared to the control group. In xenograft tumor models, the LPEI-peptide conjugate promoted transgene expression showing a clear-cut response to PKC alpha. Furthermore, when a plasmid containing a therapeutic gene, human caspase-8 (pcDNA-hcasp8), was used, the LPEIpeptide conjugate had significant cancer-suppressive effects and extended animal survival. Collectively, these results reveal that our method has great potential for cancer-specific gene delivery and therapy.

DOI： 10.1021/acsbiomaterials.1c00213

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DOI： 10.2116/analsci.21P117

Language：English   Publishing type：Research paper (scientific journal)  

Butyrate has been used in the treatment of inflammatory bowel diseases (IBD). However, the controlled release of butyrate has been indicated to be necessary in order to avoid the side effects verified at high concentrations. We previously developed nanoparticles (NPs) of polyvinyl butyrate (PVBu) as an oral butyrate donor for the controlled release of butyrate for the treatment of colitis. To examine the effect of the size of NPs on the therapeutic effect of colitis, here we prepared PVBu NPs with different sizes (100 nm and 200 nm). Both sizes of PVBu NPs significantly suppressed the inflammatory response in macrophages in vitro. PVBu NPs with 200 nm showed better effects on the amelioration of colitis compared with the 100 nm-NPs. We found unexpectedly that 200 nm-NP incorporated with all-trans retinoic acid (ATRA) showed a much better therapeutic effect than those with unloaded 200 nm-NPs, although ATRA alone was reported to worsen the inflammation. The synergistic effect of ATRA with butyrate shows evidence of being a promising approach for IBD treatment.

DOI： 10.3390/polym13091472

Language：English   Publishing type：Research paper (scientific journal)  

Antibody-recruiting molecules (ARMs) are bispecific molecules composed of an antibody-binding motif and a target-binding motif that redirect endogenous antibodies to target cells to elicit immune responses. To enhance the translational potential of ARMs, it is crucial to design antibody/target-binding motifs that have strong affinity and are easy to synthesize. Here, we synthesized a novel Fc-binding ARM (Fc-ARM) that targets folate receptor (FR)-positive cancer cells, Reo-3, using a recently developed monocyclic peptide 15-Lys8Leu, which binds strongly to the Fc region of an antibody. Reo-3 bound to the Fc region of the antibody with a K-d of 5.8 nM, and recruited a clinically used antibody mixture to attack FR-positive IGROV-1 cells as efficiently as Fc-ARM2, in which a bicyclic Fc-binding peptide was used. These results indicate that 15-Lys8Leu, which can be synthesized readily, is suitable for various applications including the development of Fc-ARMs.

DOI： 10.1039/d0md00337a

Language：English   Publishing type：Research paper (scientific journal)  

Butyrate has been attracting attention for the suppression of inflammatory bowel disease (IBD). However, clinical trials of butyrate for IBD treatment have resulted in controversial outcomes, likely owing to the adverse effect of butyrate on the intestinal epithelium that was observed at high butyrate concentrations. Herein, we propose polyvinyl butyrate (PVBu) nanoparticles (NPs) as butyrate donors for delivery to the lower part of the intestine for the treatment of colitis. The PVBu NPs suppressed the inflammatory activation of macrophages in vitro, although sodium butyrate inversely further activated macrophages. Oral administration of NPs did not change the luminal concentration of free butyrate; however, NPs showed a therapeutic effect on a colitis mouse model. In addition, incorporation of vitamin D-3 into the NPs enhanced the therapeutic effect on colitis. Hence, PVBu NPs are a promising therapeutic for IBD treatment, not only as a butyrate donor but also as a carrier for hydrophobic drugs like vitamin D-3.

DOI： 10.1021/acsabm.0c01105

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We previously developed a hydrolase-based fluorescence amplification method for antigen-specific cell labelling, in which fluorescent substrates stained cells by a non-covalent hydrophobic interaction. To improve the substrates retention in cells, we examined the effect of a chloroacetyl group modification on the substrate retention. We found that the chloroacetyl group suppressed the dissociation of the substrate after forming a covalent bond with intracellular proteins. However, the slow reaction speed of the chloroacetyl group allowed dissociation for cells in the early stage of the staining reaction.

DOI： 10.2116/analsci.20SCN03

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DOI： 10.2116/analsci.20P443

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DOI： 10.2116/analsci.20SCN03

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Synthetic small molecules that redirect endogenous antibodies to target cells are promising drug candidates because they overcome the potential shortcomings of therapeutic antibodies, such as immunogenicity and the need for intravenous delivery. Previously, we reported a novel class of bispecific molecules targeting the antibody Fc region and folate receptor, named Fc-binding antibody-recruiting molecules (Fc-ARMs). Fc-ARMs can theoretically recruit most endogenous antibodies, inducing antibody-dependent cell-mediated cytotoxicity (ADCC) to eliminate cancer cells. Herein, we describe new Fc-ARMs that target prostate cancer (Fc-ARM-Ps). Fc-ARM-Ps recruited antibodies to cancer cells expressing prostate-specific membrane antigen but did so with lower efficiency compared with Fc-ARMs targeting the folate receptor. Upon recruitment by Fc-ARM-P, defucosylated antibodies efficiently activated natural killer cells and induced ADCC, whereas antibodies with intact N-glycans did not. The results suggest that the affinity between recruited antibodies and CD16a, a type of Fc receptor expressed on immune cells, could be a key factor controlling immune activation in the Fc-ARM strategy.

DOI： 10.1002/cbic.202000577

Language：English   Publishing type：Research paper (scientific journal)  

We have validated that ligand peptides designed from antigen peptides could be used for targeting specific major histocompatibility complex class I (MHC-I) molecules on the cell surface. To design the ligand peptides, we used reported antigen peptides for each MHC-I molecule with high binding affinity. From the crystal structure of the peptide/MHC-I complexes, we determined a modifiable residue in the antigen peptides and replaced this residue with a lysine with an e-amine group modified with functional molecules. The designed ligand peptides successfully bound to cells expressing the corresponding MHC-I molecules via exchange of peptides bound to MHC-I. We demonstrated that the peptide ligands could be used to transport a protein or a liposome to cells expressing the corresponding MHC-I. This strategy may be useful for targeted delivery to cells overexpressing MHC-I, which have been observed in autoimmune diseases.

DOI： 10.1021/acs.biochem.0c00735

Language：English   Publishing type：Research paper (scientific journal)  

The nanoparticles (NPs) from polyvinyl butyrate (PVBu) which can work as an orally applicable donor of butyrate for intestine were prepared. Immunotolerance inducing molecules such as vitamin D-3 and all-trans retinoic acid (ATRA) were incorporated into PVBu NPs. The alteration in populations and numbers of DC103(+) dendritic cells (DC) and regulatory T (Treg) cells in intestinal immune tissues were examined after oral administration of NPs. It was found that NPs reduced the population of CD103(+) DC and Treg cells in Peyer's patched in lower part of the intestine and inversely increased the population of CD103(+) DC in mesenteric lymph node (MLN), while the population of Treg cells in MLN was unchanged. These observations indicate that NPs may enhance the immunotolerance at MLN and lamina propria toward luminal antigens, indicating the promising features of PVBu NPs as therapeutics of allergy and autoimmune diseases.

DOI： 10.1016/j.pnsc.2020.10.003

Language：English   Publishing type：Research paper (scientific journal)  

In this report, we designed conjugates of an antigen peptide with the immunosuppressive vitamins all-transretinoic acid (ATRA) and vitamin D3 for efficient induction of antigen-specific immunotolerance. We established a synthetic scheme for the preparation of the peptide-vitamin conjugates, which the chemically unstable vitamins tolerated. Among the obtained conjugates, the ATRA conjugate successfully suppressed inflammatory effects in macrophages and dendritic cells and induced antigen presentation in dendritic cells. This synthetic method of conjugate is conceivably applicable to other antigen peptides for induction of antigen-specific immunotolerance.

DOI： 10.1002/psc.3275

Language：English   Publishing type：Research paper (scientific journal)  

In the early stage of tumor development, tumor-associated macrophages (TAM) works to suppress tumor growth by secreting soluble factors including nitric oxide (NO). L-Arginine (Arg) is a substrate of nitric oxide synthase (NOS) expressed in TAM. Here we examined whether NO produced from Arg by macrophages works to enhance the effect of the anti-cancer drug, doxorubicin (Dox) by using a co-culture system of cancer cells with macrophages. By employing colorimetric analyses methods (Griess Reagent and Cell Counting kit-8), we found that NO produced from Arg by co-cultured macrophages could enhance the cytotoxic effect of Dox to cancer cells. Moreover, we found that augmentation is affected by the order of the addition of Arg and Dox. A prior addition of Arg to Dox and simultaneous addition showed the same enhancement effect, but a prior addition of Dox to Arg abolished the augmentation. This suggests that the co-administration of Arg with Dox would be an effective treatment to improve chemo-therapies.

DOI： 10.2116/analsci.20P200

Language：English   Publishing type：Research paper (scientific journal)  

The gut liver axis may be involved in non-alcoholic steatohepatitis (NASH) progression. Pathogen-associated molecular patterns leak through the intestinal barrier to the liver via the portal vein to contribute to NASH development. Active vitamin D-3 (1,25(OH)(2)D-3) is a potential therapeutic agent to enhance the intestinal barrier. Active vitamin D-3 also suppresses inflammation and fibrosis in the liver. However, the adverse effects of active vitamin D-3 such as hypercalcemia limit its clinical use. We created a nano-structured lipid carrier (NLC) containing active vitamin D-3 to deliver active vitamin D-3 to the intestine and liver to elicit NASH treatment. We found a suppressive effect of the NLC on the lipopolysaccharide-induced increase in permeability of an epithelial layer in vitro. Using mice in which NASH was induced by a methionine and choline-deficient diet, we discovered that oral application of the NLC ameliorated the permeability increase in the intestinal barrier and attenuated steatosis, inflammation and fibrosis in liver at a safe dose of active vitamin D-3 at which the free form of active vitamin D-3 did not show a therapeutic effect. These data suggest that the NLC is a novel therapeutic agent for NASH.

DOI： 10.1248/bob.b20-00432

Language：English   Publishing type：Research paper (scientific journal)  

Enhancing blood flow to tumors is a prominent strategy for improving the tumor accumulation of macromolecular drugs through the enhanced permeability and retention (EPR) effect. IRL-1620 is an agonist of the endothelin B receptor, and is a promising molecule to enhance tumor blood flow by activating endothelial nitric oxide synthase. However, contradictory effects on tumor blood flow modulation have been reported because the effects of IRL-1620 may differ in different animal models. Here, we examined for the first time the effect of IRL-1620 on the EPR effect for PEGylated liposomes in a CT-26 murine colon cancer model. Co-injection of IRL-1620 at an optimum dose (3nmol/kg) nearly doubled the tumor accumulation of liposomes compared with controls, indicating that IRL-1620 enhanced the EPR effect in the present colon cancer model. Co-injection of IRL-1620 is a promising strategy to improve the therapeutic effects of macromolecular drugs while reducing their side effects.

DOI： 10.1248/bpb.b20-00367

Language：English  

Although monoclonal antibodies (mAbs) have revolutionized cancer treatment, their accumulation in solid tumors is limited and requires improvement to enhance therapeutic efficacy. Here we developed a strategy to modify mAb with a donor of nitric oxide (NO) because NO functions to vasodilate as well as to enhance the permeability of vascular endothelium, which will contribute to enhancing the tumor accumulation of mAb. We selected S-nitrosothiol as a NO donor and established the procedure to modify S-nitrosothiol group on mAb under ambient conditions. The modified mAb (Ab-SNO) thus obtained released NO in a preferable speed and maintained its original properties such as binding affinity to a target antigen and efficacy to induce antibody-dependent cellular cytotoxicity. We demonstrated that Ab-SNO enhanced the tumor accumulation of co-administered proteins such as antibody and serum albumin.

DOI： 10.1016/j.ijpharm.2020.119352

Language：English   Publishing type：Research paper (scientific journal)  

Blood retention and antigenicity of polycarboxybetaine-modified liposomes

Language：English   Publishing type：Research paper (scientific journal)  

Induction of ADCC by a folic acid-mAb conjugate prepared by tryptophan-selective reaction toward folate-receptor-positive cancer cells
We developed conjugates between monoclonal antibody (mAb) and folic acid (FA) by using a tryptophan (Trp)-selective reaction, which yields relatively homogenous products compared to conventional methods. The obtained mAb-FA conjugates showed significant cellular cytotoxicity toward folate receptor-expressing cancer cells, demonstrating that the conjugates retained the Fc region's original function.

DOI： 10.1039/d0ra03291c

Language：English  

Language：English  

Redirecting endogenous antibodies in the bloodstream to tumor cells using synthetic molecules is a promising approach to trigger anti-tumor immune responses. However, current molecular designs only enable the use of a small fraction of endogenous antibodies, limiting the therapeutic potential. Here, we report Fc-binding antibody-recruiting molecules (Fc-ARMs) as the first example addressing this issue. Fc-ARMs are composed of an Fc-binding peptide and a targeting ligand, enabling the exploitation of endogenous antibodies through constant affinity to the Fc region of antibodies, whose sequence is conserved in contrast to the Fab region. We show that Fc-ARM targeting folate receptor-α (FR-α) redirects a clinically used antibody mixture to FR-α⁺ cancer cells, resulting in cancer cell lysis by natural killer cells in vitro. Fc-ARMs successfully interacted with antibodies in vivo and accumulated in tumors. Furthermore, Fc-ARMs recruited antibodies to suppress tumor growth in a mouse model. Thus, Fc-ARMs have the potential to be a novel class of cancer immunotherapeutic agents.

DOI： 10.1039/d0sc00017e

Language：English   Publishing type：Research paper (scientific journal)  

We previously proposed using a hydrolysis enzyme for fluorescent signal amplification in flow cytometric detection of antigen proteins, which was named the catalyzed reporter penetration (CARP) method. In this method, antigen proteins are labeled with enzyme-modified antibodies, and then fluorophore-modified substrates stain cells by penetrating the cell membrane upon hydrolysis of the substrate. We proved the concept by using alkaline phosphatase (AP) as the hydrolysis enzyme. However, a required prior inactivation process of endogenous AP activity on the cell surface risked disrupting recognition of antigen proteins by antibodies. In this report, the CARP method was extended to β-galactosidase (β-gal) as an amplification enzyme, which circumvented the requirement of an initial inactivation process because endogenous β-gal activity on the surface of examined cells was found to be negligible. The substrate structure for β-gal was optimized and used for the CARP method. The CARP method showed significantly higher fluorescent signals than a conventional method using fluorophore-modified antibodies. Moreover, the degree of amplification of the fluorescence signal was higher for antigens with low expression levels, showing that the CARP method is a suitable signal amplification method over current conventional approaches.

DOI： 10.1021/acs.analchem.9b04471

Language：English  

We previously proposed using a hydrolysis enzyme for fluorescent signal amplification in flow cytometric detection of antigen proteins, which was named the catalyzed reporter penetration (CARP) method. In this method, antigen proteins are labeled with enzyme-modified antibodies, and then fluorophore-modified substrates stain cells by penetrating the cell membrane upon hydrolysis of the substrate. We proved the concept by using alkaline phosphatase (AP) as the hydrolysis enzyme. However, a required prior inactivation process of endogenous AP activity on the cell surface risked disrupting recognition of antigen proteins by antibodies. In this report, the CARP method was extended to β-galactosidase (β-gal) as an amplification enzyme, which circumvented the requirement of an initial inactivation process because endogenous β-gal activity on the surface of examined cells was found to be negligible. The substrate structure for β-gal was optimized and used for the CARP method. The CARP method showed significantly higher fluorescent signals than a conventional method using fluorophore-modified antibodies. Moreover, the degree of amplification of the fluorescence signal was higher for antigens with low expression levels, showing that the CARP method is a suitable signal amplification method over current conventional approaches.

DOI： 10.1021/acs.analchem.9b04471

Language：English  

We report here a folate-modified membrane anchor for cell surface modification to induce cell adhesion to target cells. The membrane anchor region, which was consisted of cationic lysine residues and palmitoyl group-modified residues, was modified with folate through an oligoethlene glycol linker. The peptide anchor was modified on to the cell membrane by using β-cyclodextrin as a solubilizer of the peptide anchor. After modification, the peptide anchor disappeared from the cell membrane via endocytotic uptake or dissociation from the cell membrane. However, the endocytosed peptide was represented on the cell surface via recycling endosome pathway. The obtained folate-modified cells successfully adhered on to target cells which expressed folate receptor α via ligand-receptor specific interaction and adhesion continued at least 4 hours.

DOI： 10.1080/09205063.2019.1616975

Language：English   Publishing type：Research paper (scientific journal)  

We report here a folate-modified membrane anchor for cell surface modification to induce cell adhesion to target cells. The membrane anchor region, which was consisted of cationic lysine residues and palmitoyl group-modified residues, was modified with folate through an oligoethlene glycol linker. The peptide anchor was modified on to the cell membrane by using β-cyclodextrin as a solubilizer of the peptide anchor. After modification, the peptide anchor disappeared from the cell membrane via endocytotic uptake or dissociation from the cell membrane. However, the endocytosed peptide was represented on the cell surface via recycling endosome pathway. The obtained folate-modified cells successfully adhered on to target cells which expressed folate receptor α via ligand-receptor specific interaction and adhesion continued at least 4 hours.

DOI： 10.1080/09205063.2019.1616975

Language：English  

The modulation of blood flow to tumors is a prominent strategy for improving the tumor accumulation of nanomedicines, resulting from the enhanced permeability and retention (EPR) effect. We previously reported a promising EPR enhancer-a nitric oxide (NO) donor-containing liposome (NO-LP)-which showed enhanced accumulation in tumor tissue. Herein, we study NO-LP in greater detail to clarify its practical use as an EPR enhancer. NO-LP was found to have advantages as a NO donor, including the ability to maintain NO donation over long periods of time, and a constant rate of NO-release irrespective of the environmental pH. NO-LP showed rapid accumulation in tumor tissue after injection (1 h), and then accumulation was continuously enhanced until 48 h. Enhanced NO-LP accumulation was observed specifically in tumor, while the accumulation in other organs remained relatively unchanged. The results obtained show the promising features of NO-LP as an EPR enhancer.

DOI： 10.1016/j.ijpharm.2019.05.043

Language：English  

Language：English   Publishing type：Research paper (scientific journal)  

Self-Assembly of siRNA/PEG- b-Catiomer at Integer Molar Ratio into 100 nm-Sized Vesicular Polyion Complexes (siRNAsomes) for RNAi and Codelivery of Cargo Macromolecules.
Vesicular polyion complexes (PICs) were fabricated through self-assembly of rigid cylindrical molecules, small interfering RNAs (siRNAs), with flexible block catiomers of poly(ethylene glycol) (2 kDa) and cationic polyaspartamide derivative (70 units) bearing a 5-aminopentyl side chain. 100 nm-sized siRNA-assembled vesicular PICs, termed siRNAsomes, were fabricated in specific mixing ranges between siRNA and block catiomer. The siRNAsome membrane was revealed to consist of PIC units fulfilling a simple molar ratio (1:2 or 2:3) of block catiomer and siRNA. These ratios correspond to the minimal integer molar ratio to maximally compensate the charge imbalance of PIC, because the numbers of charges per block catiomer and siRNA are +70 and -40, respectively. Accordingly, the ζ-potentials of siRNAsomes prepared at 1:2 and 2:3 were negative and positive, respectively. Cross-section transmission electron microscopic observation clarified that the membrane thicknesses of 1:2 and 2:3 siRNAsomes were 11.0 and 17.2 nm, respectively. Considering that a calculated long-axial length of siRNA is 5.9 nm, these thickness values correspond to the membrane models of two (11.8 nm) and three (17.7 nm) tandemly aligned siRNAs associating with one and two block catiomers, respectively. For biological application, siRNAsomes were stabilized through membrane-cross-linking with glutaraldehyde. The positively charged and cross-linked siRNAsome facilitated siRNA internalization into cultured cancer cells, eliciting significant gene silencing with negligible cytotoxicity. The siRNAsome stably encapsulated dextran as a model cargo macromolecule in the cavity by simple vortex mixing. Confocal laser scanning microscopic observation displayed that both of the payloads were internalized together into cultured cells. These results demonstrate the potential of siRNAsomes as a versatile platform for codelivery of siRNA with other cargo macromolecules.

DOI： 10.1021/jacs.8b13641

Language：English  

DOI： 10.2745/dds.34.213

Language：English  

We report here efficient synthesis of artificial transmembrane molecules (ATMs), via click chemistry of a transmembrane part and membrane-penetrating parts. Synthesized ATMs penetrated the cell membrane by Coulombic force, while they stayed on the cell membrane once they were complexed with streptavidin.

DOI： 10.1246/cl.190009

Language：English   Publishing type：Research paper (scientific journal)  

Immunomodulatory function of all-trans retinoic acid (ATRA) has been gathering much attention for the therapy of autoimmune diseases. ATRA is a chemically unstable molecule which requires proper formulation for targeted delivery. Here we examined nanostructured lipid carrier (NLC) for the formulation of ATRA. NLC is a representative nanoparticle formulation especially suited for oral delivery. We established the preparation procedures of ATRA-containing NLC (NLC-RA) which minimizes the degradation of ATRA during the preparation process. NLC-RA thus obtained was taken up by macrophages and induced anti-inflammatory response via suppressing NF-kappa B signaling as well as via enhancing the production of anti-inflammatory cytokines. Moreover, NLC-RA enhanced differentiation of naive T cells to regulatory T cells in the co-culture system with dendritic cells. These results suggest that NLC-RA is a promising alternative therapy for the autoimmune diseases especially intestinal bowel disease.[GRAPHICS].

DOI： 10.1080/09205063.2018.1493671

Language：English   Publishing type：Research paper (scientific journal)  

The induction of antigen-specific immunotolerance has been gathering attention concerning the therapy of allergy and autoimmune diseases. Tolerogenic dendritic cells (tDCs) play crucial roles in immunotolerance therapy because they induce anergic responses for auto-reactive helper T cells, and also enhance differentiation to regulatory T cells to maintain tolerance against auto-antigens. All-trans retinoic acid (ATRA) is one of the representative molecules used to induce tDCs. We have proposed a simple formulation of ovalbumin nanoparticles complexed with ATRA (OVA/RA NPs). OVA/RA NPs were taken up by DCs and successfully induced phenotypes of tDCs.

DOI： 10.2116/analsci.18P252

Language：English   Publishing type：Research paper (scientific journal)  

Robust Polyion Complex Vesicles (PICsomes) under Physiological Conditions Reinforced by Multiple Hydrogen Bond Formation Derived by Guanidinium Groups
Polyion complex vesicles (PICsomes) formed from a self-assembly of an oppositely charged pair of block- and homo-polyelectrolytes have shown exceptional features for functional loading of bioactive agents. Nevertheless, the stability of PICsomes is often jeopardized in a physiological environment, and only PICsomes having chemically cross-linked membranes have endured in harsh in vivo conditions, such as in the bloodstream. Herein, we developed versatile PICsomes aimed to last in in vivo settings by stabilizing their membrane through a combination of ionic and hydrogen bonding, which is widely found in natural proteins as a salt bridge, by controlled introduction of guanidinium groups in the polycation fraction toward concurrent polyion complexation and hydrogen bonding. The guanidinylated PICsomes were successfully assembled under physiological salt conditions, with precise control of their morphology by tuning the guanidinium content, and the ratio of anionic and cationic components. Guanidinylated PICsomes with 100 nm diameter, which are relevant to nanocarrier development, were stable in high urea concentration, at physiological temperature, and under serum incubation, persisting in blood circulation in vivo.

DOI： 10.1021/acs.biomac.8b01097

Language：English   Publishing type：Research paper (scientific journal)  

Peripheral artery disease (PAD) is one of the most spreading diseases all over the world. The treatment strategies are limited to surgical or endovascular procedures for final stage chronic PAD or acute limb ischemia, and no pharmacological approaches have been achieved to prevent the worsening of chronic PAD or to regenerate the tissues of acute limb ischemia. Therefore, the improvement of therapeutic strategy is strongly demanded in clinics. Here, we adopted an acute hindlimb ischemia model in rats, which provides concomitant inflammatory response, to evaluate the application of drug delivery system against PAD. Through comparative experiments by using different-sized nanomedicine analogues, polyion complex (PIC) micelles with 30 nm diameter and PIC vesicles with 100- and 200-nm diameter (PICs-30, -100, -200 respectively), we found the size-dependent accumulation and retention in the collateral arteries. In contrast to PICs-30 and -200, histological analysis showed that PICs-100 were around the arterioles and co-localized with macrophages, which indicates that the PICs-100 can achieve moderate interaction with phagocytes. Our data suggests that controlling the size of nanomedicines has promise for developing novel angiogenic treatments toward the effective management of collateral arteries.

DOI： 10.1016/j.jconrel.2018.07.049

Language：English   Publishing type：Research paper (scientific journal)  

The active form of vitamin D-3, 1,25(OH)(2)D-3 has been found to exert multiple effects on the suppression of progression of inflammatory bowel disease (IBD). Vitamin D-3 has been gathering attention as a therapy for IBD. However, the clinical trials conducted to date revealed that a relatively high dosage of vitamin D-3 was required to see a significant therapeutic effect. Thus, effective formulation and delivery of vitamin D-3 to colonic inflammatory lesions will be required. Herein we describe the preparation of a nanostructured lipid carrier (NLC) for the encapsulation of 1,25(OH)(2)D-3 for colonic delivery via oral administration. The optimized fabrication procedure enabled the incorporation of 1,25(OH)(2)D-3 in the NLC by minimizing the destruction of chemically unstable 1,25(OH)(2)D-3. The obtained NLCs orally delivered 1,25(OH)(2)D-3 to the colon in mice and maintained a high concentration of 1,25(OH)(2)D-3 in the colonic tissue for at least 12 h. The NLC showed multiple effects on the suppression of symptoms of colitis induced by dextran sodium sulfate, namely maintaining crypt structure, reducing the tissue concentration of inflammatory cytokines, suppressing the infiltration of polymorphonuclear leukocytes, and augmenting anti-inflammatory CX3CR1high macrophages. Our NLCs containing 1,25(OH)(2)D-3 may be an alternative treatment for IBD therapy.

DOI： 10.1016/j.jconrel.2018.07.019

Language：English   Publishing type：Research paper (scientific journal)  

Here we present a liposome non-covalently coated with immunoglobulin G (IgG) by using a peptide ligand to the constant region of IgG. IgG coated on the liposome still maintained binding ability to a complementary antigen protein but it was not recognized by Fc gamma receptors (Fc gamma Rs) of monocytes. The stealth feature of the IgG-coated liposome may be useful to avoid clearance by macrophages in vivo to extend the blood half-life of the liposome.

DOI： 10.1246/cl.180181

Language：English   Publishing type：Research paper (scientific journal)  

Antibody-dependent cell-mediated cytotoxicity (ADCC) is caused by natural killer (NK) cells upon recognition of antigen-bound IgG via FcγRIIIa. This mechanism is crucial for cytolysis of pathogen-infected cells and monoclonal antibody (mAb)-mediated elimination of cancer cells. However, there is concern that mAb-based cancer therapy induces ADCC against non-target cells expressing antigens. To date, no strategy has been reported to enhance the selectivity of ADCC to protect non-target cells expressing antigens. Here, we introduce a model inhibitor which specifically blocks ADCC of anti-EGFR mAbs towards EGFR/folate receptor α (FRα) double positive cells. This inhibitor recruits mAbs on the FRα of the cell surface independent of Fab antigen recognition. The resulting ternary and/or quaternary complexes formed on the cell surface suppress signal transduction of FcγRIIIa in NK cells, consequently leading to more specific ADCC.

DOI： 10.1039/c8md00010g

Language：Japanese  

効率的な光線力学療法を指向したハイブリッド型光増感剤送達システム

Language：Japanese  

Language：English  

Coating liposome surfaces with human serum albumin (HSA) can improve the colloidal stability and prevent opsonization. HSA coating via specific binding with alkyl ligands is promising because although the ligand-mediated coating is relatively stable it can spontaneously exchange with fresh HSA. However, to achieve surface coating with HSA, multiple hydrophobic ligands must be exposed to an aqueous medium prior to binding with HSA. This presents a challenge, as hydrophobic ligands tend to be buried in the liposomal membrane. Here we present the first HSA modification of liposome surfaces via alkyl ligands. We found that a relatively short alkyl ligand, or a long alkyl ligand with a terminal carboxylate, could be exposed on the liposome surface without causing aggregation of the liposomes and these ligands could subsequently bind HSA. The resulting HSA-coated liposomes were as inert as conventional PEGylated liposomes in terms of macrophage recognition.

DOI： 10.1021/acs.langmuir.7b04024

Language：English   Publishing type：Research paper (scientific journal)  

Contrast-variation small-angle neutron scattering (CV-SANS), small-angle X-ray scattering (SAXS), nuclear magnetic resonance (NMR) measurements of diffusion and isothermal titration calorimetry (ITC) are used to gain insight into the aggregation of an alkyl-C60 derivative, molecule 1, in n-hexane, n-decane and toluene as a function of concentration and temperature. Results point to an associative mechanism of aggregation similar to other commonly associating molecules, including non-ionic surfactants or asphaltenes in non-aqueous solvents. Little aggregation is detected in toluene, but small micelle-like structures form in n-alkane solvents, which have a C60-rich core and alkyl-rich shell. The greatest aggregation extent is found in n-hexane, and at 0.1 M the micelles of 1 comprise around 6 molecules at 25 °C. These micelles become smaller when the concentration is lowered, or if the solvent is changed to n-decane. The solution structure is also affected by temperature, with a slightly larger aggregation extent at 10 °C than at 25 °C. At higher concentrations, for example in solutions of 1 above 0.3 M in n-decane, a bicontinuous network becomes apparent. Overall, these findings aid our understanding of the factors driving the assembly of alkyl-π-conjugated hydrophobic amphiphiles such as 1 in solution and thereby represent a step towards the ultimate goal of exploiting this phenomenon to form materials with well-defined order.

DOI： 10.1039/c7cp06348b

Language：English  

Despite the expanding use of flow cytometry, its detection limit is not satisfactory for many antigen proteins with low copy numbers. Herein, we describe an alkaline phosphatase (AP)-based technique to amplify the fluorescence signal for cell staining applications. We designed a fluorescent substrate that acquires membrane permeability upon dephosphorylation by AP. By using the substrate, the fluorescence signal of cells in flow cytometry could be successfully amplified to give a much stronger signal than the cells labeled using a conventional fluorophore-modified antibody.

DOI： 10.1021/acs.analchem.7b03893

Language：English   Publishing type：Research paper (scientific journal)  

Therapeutic peptides and diagnostic agents with their molecular size below the renal clearance threshold suffer from short blood circulation time. Here, we report a novel design of peptide-based ligand with a strong binding affinity to human serum albumin (HSA), which can be used as a tag to extend the blood circulation of small-size molecules. We designed ligands with dual alkyl groups connected with a negatively charged spacer. The ligands showed both higher binding affinity to HSA and a higher retention in mice blood than that of a single alkylated peptide.

DOI： 10.2116/analsci.17P614

Language：Japanese  

Language：English   Publishing type：Research paper (scientific journal)  

In this work, we have developed a new technique to stabilize a ternary complex composed of plasmid DNA, a linear polyethyleneimine (LPEI) and serum albumin. A stearoyl group was conjugated to LPEI as a specific ligand for serum albumin. The resultant ternary complex has excellent stability in physiological saline conditions, maintaining its initial diameter and preventing aggregation of red blood cells. The ternary complex has equivalent transfection ability to and significantly lower cytotoxicity than unmodified LPEI. Therefore, the ternary complex is potentially useful as a new gene carrier, possessing high blood stability.

DOI： 10.1080/09205063.2017.1328730

Language：English   Publishing type：Research paper (scientific journal)  

Applications of enzymes are intensively studied, particularly for biomedical applications. However, encapsulation or immobilization of enzymes without deactivation and long-term use of enzymes are still at issue. This study focuses on the polymeric vesicles "PICsomes" for encapsulation of enzymes to develop a hecto-nanometer-scaled enzyme-loaded reactor. The catalytic activity of a PICsome-based enzyme nanoreactor is carefully examined to clarify the effect of compartmentalization by PICsome. Encapsulation by PICsome provides a stability enhancement of enzymes after 24 h incubation at 37 degrees C, which is particularly helpful for maintaining the high effective concentration of beta-galactosidase. Moreover, to control the microenvironment inside the nanoreactor, a large amount of dextran, a neutral macromolecule, is encapsulated together with beta-galactosidase in the PICsome. The resulting dextran-coloaded nanoreactor contributes to the enhancement of enzyme stability, even after exposure to 24 h incubation at -20 degrees C, mainly due to the antifreezing effect.

DOI： 10.1002/mabi.201600542

Language：Others  

Enzyme-catalyzed amplification of fluorescent immunolabeling of a single cell for high-sensitive flow cytometry

Language：English   Publishing type：Research paper (scientific journal)  

Inflammatory activation of macrophages is a key factor in chronic inflammatory diseases such as ulcerative colitis. The excessive production of reactive oxygen species (ROS)/reactive nitrogen species (RNS) by macrophages causes oxidative stress during the inflammatory response and exaggerates inflammatory lesions in ulcerative colitis. Inhibition of the inflammatory activation of macrophages is a promising treatment for chronic inflammatory diseases. Here, we prepared self-filling polymer-lipid hybrid nanoparticles (PST-PLNPs) consisting of poly DL-lactic acid as a hydrophobic biodegradable polymer core encapsulating alpha-tocopherol (T) and phosphatidylserine (PS) both on the surface and interior of the particle. We confirmed the anti-inflammatory response of these hybrid nanoparticles in activated murine macrophages. PS has anti-inflammatory effects on macrophages by modulating the macrophage phenotype, while alpha-tocopherol is an antioxidant that neutralizes ROS. We found that PS-containing (PS-PLNPs) and PS plus alpha-tocopherol-containing (PST-PLNPs) polymer-lipid hybrid nanoparticles significantly increased the viability of lipopolysaccharide (LPS)-treated macrophages compared with phosphatidylcholine-containing PLNPs. PST-PLNPs had a better effect than PS-PLNPs, which was attributed to the synergy between PS and alpha-tocopherol. This synergic action of PST-PLNPs reduced NO and pro-inflammatory cytokine (IL-6) production and increased anti-inflammatory cytokine (TGF-beta 1) production when incubated with activated macrophages. Thus, these self-filling biodegradable polymer-lipid hybrid nanoparticles (PST-PLNPs) containing antioxidant and anti-inflammatory molecules might be potential alternative drug carriers to liposomes and polymeric nanoparticles for the treatment of chronic inflammatory diseases such as ulcerative colitis.

DOI： 10.1039/c7md00174f

Language：English   Publishing type：Research paper (scientific journal)  

The introduction of proteins into dendritic cells (DCs) ex vivo is a critical step for the DC-based immunotherapy of cancer. Here, we developed a biotin-modified polymer with multiple hydrophobic membrane anchors for cells that functions as a synthetic receptor for an antigen protein, ovalbumin (OVA), to introduce it efficiently into DCs compared with the conventional pulsing method. Our method showed significant advantages, including the rapid incorporation of OVA and the activation of antigen-specific T cells in a MHC-restricted manner. When mice were immunized by DCs treated with our method, tumor growth was completely suppressed, indicating that our method can be used to prepare adjuvant DCs.

DOI： 10.1039/c7md00188f

Language：English   Publishing type：Research paper (scientific journal)  

The use of imaging agents to visualize tumor cells is an advantageous technique to achieve a more efficient intraoperative diagnosis and effective debulking operations. Targeting of these agents to certain receptors that are overexpressed in cancer cells, such as the folate receptor, aids in tumor targeting. Several imaging probes have been developed using this strategy. However, these ligand-targeting cancer imaging probes are rapidly cleared during systemic delivery due to their small size, which compromises their biodistribution and circulation. Improving the detection of cancer requires higher accumulation and effective retention activities of imaging probes. Here we developed a new design for a folate-fluorophore conjugate that is modified with palmitoyl. Palmitic acid has a strong binding affinity with human serum albumin (HSA), which has the ability to form non-covalent host-guest complexes and has a blood half-life of 19 days. In this strategy, HSA is expected to serve as an endogenous nanocarrier for the designed probe in blood circulation. We hypothesized that via a reversible interaction with HSA, this simple palmitoyl modification on a folate-fluorophore conjugate can induce long blood circulation of the probe. Our folate-targeted probe could show longer blood circulation compared to the probe which lacks palmitoyl.

DOI： 10.1039/c7md00102a

Language：English   Publishing type：Research paper (scientific journal)  

We propose a method to improve the enhanced permeability and retention (EPR) effect of nanomedicines based on tumor-specific vasodilation using a nitric oxide (NO) donor-containing liposome. NONOate, a typical NO donor, was incorporated into a PEGylated liposome to retard the protonation-induced release of NO from NONOate by the protecting lipid bilayer membrane. The NONOate-containing liposome (NONOate-LP) showed similar blood retention to an empty PEGylated liposome but almost twice the amount accumulated within the tumor. This improvement in the EPR effect is thought to have been caused by specific vasodilation in the tumor tissue by NO released from the NONOate-LP accumulated in the tumor. The improved EPR effect by NONOate-LP will be useful for the accumulation of co-administered nanomedicines.

DOI： 10.1039/c6md00614k

Language：English   Publishing type：Research paper (scientific journal)  

We developed a strategy to modify cell membranes with an artificial transmembrane receptor. Coulomb force on the receptor, caused by the membrane potential, was used to achieve membrane penetration. A hydrophobically modified cationic peptide was used as a membrane potential sensitive region that was connected to biotin through a transmembrane oligoethylene glycol (OEG) chain. This artificial receptor gradually disappeared from the cell membrane via penetration despite the presence of a hydrophilic OEG chain. However, when the receptor was bound to streptavidin (SA), it remained on the cell membrane because of the large and hydrophilic nature of SA.

DOI： 10.1021/acs.bioconjchem.6b00449

Language：English   Publishing type：Research paper (scientific journal)  

Nanoparticles have been widely utilized to deliver drugs from blood vessels to target tissues. A crucial issue concerning nanoparticle-based drug delivery is to discuss the relationship between experimentally-obtained permeability and physical parameters. Although nanoparticles can permeate vascular pores, because the size and shape of the pores are essentially non-uniform, conventional animal testing and recent cell-based microfluidic devices are unable to precisely evaluate the effects of physical parameters (e.g. pore size and nanoparticle size) on permeation. In this study, we present a membrane integrated microfluidic device to study permeation of nanoparticles through straight micropores. Porous membranes possessing uniform straight pores were utilized. The effects of pore size and pressure difference across the pores on nanoparticle permeation were examined. The experimentally determined permeability coefficient of 1.0 mu m-pore membrane against 100 nm-diameter nanoparticles agreed well with the theoretical value obtained for convectional permeation. Our method can be utilized to clarify the relationship between the experimentally-obtained permeability and physical parameters, and will help rational design of nanomedicines.

DOI： 10.2116/analsci.32.1307

Language：Japanese  

次世代医療を支えるバイオマテリアルのイノベーション 酸応答性無機有機ハイブリッド型光増感剤デリバリーシステム

Language：English  

SPIO‐loaded and cyclic RGD installed polyion complex vesicles for the neovascular imaging of orthotopic glioblastomas

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1039/c6bm00011h

Language：English   Publishing type：Research paper (scientific journal)  

Neuroinflammation caused by microglial activation is a key contributing factor in neurological disorders such as those involving ischaemia. Excess production of reactive oxygen species (ROS) and nitric oxide (NO) stimulates the inflammatory response during ischaemia, significantly damaging cells. Inhibition of inflammatory activation of microglia is a promising potential treatment approach for neurological diseases. In this study, we introduce -tocopherol and phosphatidylserine (PS) containing liposomes (PST-liposomes) to inhibit the microglial inflammatory response. PS is known to have anti-inflammatory effects on microglia by modulating the microglial phenotype, while -tocopherol is an antioxidant, known to neutralize ROS. We found that both PS-containing liposomes (PS-liposomes) and PST-liposomes, as compared with phosphatidylcholine containing liposomes, significantly increased viability of hypoxia-treated microglia. The PST-liposomes functioned better than the PS-liposomes and we attribute this superior effect to a synergy between PS and -tocopherol. This synergic action of PST-liposomes was illustrated in their ability, when incubated with microglia, to reduce NO and pro-inflammatory cytokine (TNF-) production and increase anti-inflammatory cytokine (TGF-1) production. Thus, the improved viability of hypoxia-treated microglia when treated with PST-liposomes involved anti-inflammatory effects, including ROS neutralization, as well as induction of a microglial phenotypic change. Our results suggest that PST-liposomes represent a potential therapeutic approach to reducing ischaemic injury in the brain.

DOI： 10.1080/09205063.2015.1125565

Language：English   Publishing type：Research paper (scientific journal)  

P-glycoprotein (Pgp) is a 170-kDa transmembrane protein that mediates the efflux of anticancer drugs from cells. Pgp overexpression has a distinct role in cells exhibiting multidrug resistance (MDR). We examined reversal of drug resistance in human MDR breast cancer cells by inhibition of protein kinase C alpha (PKC alpha) activity, which is associated with Pgp-mediated efflux of anticancer drugs. PKC alpha activity was confirmed by measurement of phosphorylation levels of a PKC alpha-specific peptide substrate (FKKQGSFAKKK-NH2), showing relatively higher basal activity in drug-resistant MCF-7/ADR cells (84 &#37;) than that in drug-sensitive MCF-7 cells (63 &#37;). PKC alpha activity was effectively suppressed by the PKC inhibitor, Ro-31-7549, and reversal of intracellular accumulation of doxorubicin was observed by inhibition of PKC alpha activity in MCF-7/ADR cells compared with their intrinsic drug resistance. Importantly, increased accumulation of doxorubicin could enhance the therapeutic efficacy of doxorubicin in MDR cells significantly. These results suggest a potential for overcoming MDR via inhibition of PKC alpha activity with conventional anticancer drugs.

DOI： 10.1007/s13277-015-3963-4

Language：English   Publishing type：Research paper (scientific journal)  

Systemically injectable enzyme-loaded polyion complex vesicles as in vivo nanoreactors functioning in tumors

DOI： 10.1002/ange.201508339

Language：English   Publishing type：Research paper (scientific journal)  

Controlling inflammatory response is important to avoid chronic inflammation in many diseases including atopic dermatitis (AD). In this research, we tried using a phosphatidylserine (PS)-coated microparticles in the AD mouse model for achieving the modulation of the macrophage phenotype to an anti-inflammatory state. Here, we prepared poly (D,L-lactic acid) microparticle coated with PS on the outside shell. We confirmed the cellular uptake of the PS-coated microparticle, which leads to the significant downregulation of the inflammatory cytokine production. In the mouse model of AD, the PS-coated microparticle was injected subcutaneously for a period of 12days. The mice showed significant reduction in the development of AD symptoms comparing with the mice treated with the PC-coated microparticle.

DOI： 10.1080/09205063.2015.1100844

Language：English   Publishing type：Research paper (scientific journal)  

We synthesized polymeric gene carriers consisting of poly-L-lysine (PLL) main chain modified both with substrate peptide for protein kinase C (PKC) and alkanethiol (pentadecanethiol). Due to the grafted substrate peptide, the polyplex prepared from these carriers is expected to show gene expression triggered by the phosphorylation of the peptide by intracellular PKC. The modified alkanethiol on the main chain stabilized the polyplex both via disulfide crosslinking and hydrophobic interaction. The polyplex found to show gene expression in vitro when the alkanethiol content in the main chain was enough low (4-mol&#37;-modification of PLL's epsilon-amine group) to minimize cytotoxic effect. Even though the content of alkanethiol is low, the polyplex had significant stability in a model serum solution and showed longer blood circulation in vivo. The polyplex clearly accumulated in tumor after intravenous injection.

DOI： 10.1080/09205063.2015.1054922

Language：English   Publishing type：Research paper (scientific journal)  

Introduction of ligands into 100 nm scaled hollow capsules has great potential for diagnostic and therapeutic applications in drug delivery systems. Polyethylene glycol-conjugated (PEGylated) polyion complex vesicles (PICsomes) are promising hollow nano-capsules that can survive for long periods in the blood circulation and can be used to deliver water-soluble macromolecules to target tissues. In this study, cyclic RGD (cRGD) peptide, which is specifically recognized by alpha(V)beta(3) and alpha(v)beta(5) integrins that are expressed at high levels in the neovascular system, was conjugated onto the distal end of PEG strands on PICsomes for active neovascular targeting. Density-tunable cRGD-conjugation was achieved using PICsomes with definite fraction of end-functionalized PEG, to substitute 20, 40, and 100&#37; of PEG distal end of the PICsomes to cRGD moieties. Compared with control-PICsomes without cRGD, cRGD-PICsomes exhibited increased uptake into human umbilical vein endothelial cells. Intravital confocal laser scanning microscopy revealed that the 40&#37;-cRGD-PICsomes accumulated mainly in the tumor neovasculature and remained in the perivascular region even after 24 h. Furthermore, we prepared superparamagnetic iron oxide (SPIO)-loaded cRGD-PICsomes for magnetic resonance imaging (MRI) and successfully visualized the neovasculature in an orthotopic glioblastoma model, which suggests that SPIO-loaded cRGD-PICsomes might be useful as a MRI contrast reagent for imaging of the tumor microenvironment, including neovascular regions that overexpress alpha(V)beta(3) integrins.

DOI： 10.1088/1468-6996/16/3/035004

Language：English   Publishing type：Research paper (scientific journal)  

We reported here an alternative strategy of antibody internalization by crosslinker-mediated endocytosis. This crosslinker consists of IgG binding peptide and folic acid as cancer targeting ligands toward the folate receptor, which highly expresses in many cancer cells surface. This crosslinker successfully facilitated antibody internalization into cancer cell by the folate receptor-mediated endocytosis.

DOI： 10.1246/cl.141157

Language：English   Publishing type：Research paper (scientific journal)  

We reported here an alternative strategy of antibody internalization by crosslinker-mediated endocytosis. This crosslinker consists of IgG binding peptide and folic acid as cancer targeting ligands toward the folate receptor, which highly expresses in many cancer cells surface. This crosslinker successfully facilitated antibody internalization into cancer cell by the folate receptor-mediated endocytosis.

DOI： 10.1246/cl.141157

Language：English   Publishing type：Research paper (scientific journal)  

Amphiphilic polymers bearing hydrophobic alkyl groups are expected to be applicable for both ligand presentation on the cell surface and intercellular crosslinking. To explore the optimum design for each application, we synthesized eight different acyl-modified dextrans with varying molecular weight, alkyl length, and alkyl modification degree. We found that the behenate-modified polymers retained on the cell surface longer than the palmitate-modified ones. Since the polymers were also modified with biotin, streptavidin can be presented on the cell surface through biotin-streptavidin recognition. The duration of streptavidin on the cell surface is longer in the behenate-modified polymer than the palmitate-modified one. As for the intercellular crosslinking, the palmitate-modified polymers were more efficient than the behenate-modified polymers. The findings in this research will be helpful to design the acyl-modified polymers for the cell surface engineering.

DOI： 10.1080/09205063.2015.1007414

Language：Japanese  

腫瘍においてクスリを「つくる」酵素封入PICsomeの創製

Language：English   Publishing type：Research paper (scientific journal)  

Small interfering RNA (siRNA) is regarded as a promising tool for cancer therapy because of the wide applicability to various cancer-related genes. However, non-specific delivery of siRNA is one of the major causes of adverse effects. To access the issue, here we designed a new siRNA system which turns on RNAi responding to a cancer cell-specific protease, cathepsin B. The system uses a peptide nucleic acid (PNA)-peptide conjugate to provide this protease-responsive activation. The PNA-peptides were found to form hybrids with double-stranded RNAs with complementary protruding regions, which then affected the susceptibility of dsRNA to Dicer. The dsRNA/PNA-peptide hybrids were activated in cancer cells with a high cathepsin B activity to show RNAi.

DOI： 10.1039/c5ra17737e

Language：English   Publishing type：Research paper (scientific journal)  

A rational design strategy has been developed for the construction of stable peptide-based anchors for the efficient modification of cell surfaces. Six types of peptide composed of five residues with divalent hydrophobic groups have been designed using this new strategy. Among them, a peptide with a sequence of NBD-Lys-Lys(X)-Lys-Lys-Lys(X)-NH2 (NBD: fluorophore, Lys(X): N-e-palmitoyl-l-lysine) was found to show the highest modification efficacy and longevity in culture medium. The good performance of this peptide was attributed to (1) its high aqueous solubility, which allowed it to partition from the medium to the cell surface, and (2) the high binding affinity of the saturated palmitoyl groups to the cell membrane. We found that the distribution of the peptide was affected by recycling endosome, which enabled the representation of the peptide following its endocytotic disappearance from the cell membrane. Biotin was also presented on the cell surface using this peptide-based anchor to examine its recognition by streptavidin. The efficacy of the recognition process increased as the length of the oligoethylene glycol spacer increased, indicating that it was necessary for the biotin tag to move away from the membrane glycoproteins on the cell surface to facilitate its efficient recognition by streptavidin.

DOI： 10.1021/bc500465j

Language：Japanese  

Language：English   Publishing type：Research paper (scientific journal)  

Herein, we reported a design of liposome affording a reversible coating of serum albumin on its surface. We synthesized a lipid modified with a serum albumin-specific endogenous ligand and prepared liposome, including this lipid. We successfully confirmed the coating of the liposome surface with serum albumin. The liposome presented here would be applicable to a drug carrier with enhanced blood circulation.

DOI： 10.1246/cl.140432

Language：English  

Language：English   Publishing type：Research paper (scientific journal)  

We demonstrate a polyion complex (PIC) nanoparticle that contains both a responsive fluorophore and an "internal standard" fluorophore for quantitative measurement of protein kinase (PK) activity. The PK-responsive fluorophore becomes more fluorescent with PK-catalyzed phosphorylation of substrate peptides incorporated in the PIC, while fluorescence from the internal standard remains unchanged during phosphorylation. This new concept will be useful for quantitative PK assays and the discovery of PK inhibitors.

DOI： 10.1021/bc500142j

Language：English  

Cyclic RGD‐linked Polyion Complex Vesicles (PICsomes) for Neovascular Targeting and Glioblastoma Imaging

Language：English   Publishing type：Research paper (scientific journal)  

In this work, we synthesized a series of poly-L-lysine (PLL)-based polymers for gene delivery, by modifying the PLL with both cationic peptide and histidine. The peptide moieties serve as cationic centers for polyplex formation, and also as substrates for protein kinase C alpha (PKC alpha), which is specifically activated in many types of cancer cells, to achieve cancer-specific gene expression. The histidine groups serve as buffering moieties to increase the ability of the plasmid DNA (pDNA)-polymer complex (polyplex) to escape the endosome and thus to promote expression of the pDNA in the transfected cells. The facile synthesis of the polymers proceeded by modifying the PLL with side-group-protected peptide and protected histidine, followed by deprotection of the functional groups. The synthesized polymers showed significant buffering capacity over the neutral to acidic pH range and showed less cytotoxicity in vitro compared with histidine-unmodified polymers. The polyplexes successfully showed PKC alpha-responsive gene expression immediately after their introduction into cancer cells and the gene expression continued for at least 24 h. These PLL-based carriers thus show promise for cancer-targeted gene therapy.

DOI： 10.1080/09205063.2013.879562

Language：English   Publishing type：Research paper (scientific journal)  

We have designed biotinylated polymers as synthetic receptors that have multiple alkyl groups for endocytotic delivery of target proteins. The polymers were stably attached to a cell surface via multivalent anchoring. The presented biotin was bound to streptavidin (SA) on the cell surface, and, via an endocytotic pathway, the cell rapidly internalized the biotinylated polymer/SA complex. The cell's uptake of the complex was not inhibited by the presence of 10&#37; fetal bovine serum, and its efficacy for the uptake of SA was the highest when compared with commercial reagents and single-anchored-type synthetic receptors. The synthetic receptor-mediated endocytosis can be used generally for other kind of protein by using SA as an adaptor molecule between a target protein and the cell-surface presented biotin. (C) 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jconrel.2013.12.024

Language：English   Publishing type：Research paper (scientific journal)  

We describe the preparation of well-defined multicompartment micelles from polybutadiene-block-poly(1-methyl-2-vinyl pyridinium methyl sulfate)-block-poly(methacrylic acid) (BVqMAA) triblock terpolymers and their use as advanced drug delivery systems for photodynamic therapy (PDT). A porphyrazine derivative was incorporated into the hydrophobic core during self-assembly and served as a model drug and fluorescent probe at the same time. The initial micellar corona is formed by negatively charged PMAA and could be gradually changed to poly(ethylene glycol) (PEG) in a controlled fashion through interpolyelectrolyte complex formation of PMAA with positively charged poly(ethylene glycol)-block-poly(L-lysine) (PLL-b-PEG) diblock copolymers. At high degrees of PEGylation, a compartmentalized micellar corona was observed, with a stable bottlebrush-on-sphere morphology as demonstrated by cryo-TEM measurements. By in vitro cellular experiments, we confirmed that the porphyrazine-loaded micelles were PDT-active against A549 cells. The corona composition strongly influenced their in vitro PDT activity, which decreased with increasing PEGylation, correlating with the cellular uptake of the micelles. Also, a PEGylation-dependent influence on the in vivo blood circulation and tumor accumulation was found. Fully PEGylated micelles were detected for up to 24 h in the bloodstream and accumulated in solid subcutaneous A549 tumors, while non- or only partially PEGylated micelles were rapidly cleared and did not accumulate in tumor tissue. Efficient tumor growth suppression was shown for fully PEGylated micelles up to 20 days, demonstrating PDT efficacy in vivo.

DOI： 10.1021/nn4028294

Language：English   Publishing type：Research paper (scientific journal)  

Organic-inorganic hybrid nanoparticles with calciumphosphate (CaP) core and PEGylated shell were developed to incorporatemagnetic resonance imaging (MRI) contrast agent diethylenetriaminepentaacetic acid gadolinium (III) (Gd-DTPA) for noninvasive diagnosis of solid tumors. A two-step preparation method was applied to elaborate hybrid nanoparticleswith a z-average hydrodynamic diameter about 80 nm, neutral surface xi-potential and high colloidal stability in physiological environments by self-assembly of poly(ethylene glycol)-b-poly(aspartic acid) block copolymer, Gd-DTPA, and CaP in aqueous solution, followed with hydrothermal treatment. Incorporation into the hybrid nanoparticles allowed Gd-DTPA to show significant enhanced retention ratio in blood circulation, leading to high accumulation in tumor positions due to enhanced permeability and retention (EPR) effect. Moreover, Gd-DTPA revealed above 6 times increase of relaxivity in the nanoparticle system compared to free form, and eventually, selective and elevated contrast enhancements in the tumor positions were observed. These results indicate the high potential of Gd-DTPA-loaded PEGylated CaP nanoparticles as a novel contrast agent for noninvasive cancer diagnosis. (C) 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jconrel.2013.10.038

Language：English   Publishing type：Research paper (other academic)  

Polyion complex (PIC) vesicles, PICsomes, are polymeric vesicles which can form through electrostatic interaction between an oppositely charged polyethylene glycol (PEG)-based block ionomers and homo ionomers. In this study, for further utilization and understanding of their characteristic dynamic properties in aqueous media, we conducted real-time observation of their responses to external electric fields (EFs). This observation was facilitated by a newly designed microfluidic channel, which enabled preparation of micrometer-sized PICsomes and observation of their behaviors under controlled EF conditions. Their non-trivial responses and their EF dependency were carefully evaluated, and some dynamic behaviors were observed in several EF conditions.

Language：English  

Polyion complex (PIC) formation is one of the most powerful techniques for obtaining molecular self-assemblies in aqueous media. The simple preparation process based on multiple electrostatic interactions is quite attractive for material syntheses, as well as biomedical applications. Therefore, it is desirable to control PIC architectures at the nanoscale in order to expand the scope of PIC materials. In this review article, recent progress on PIC vesicles (PICsomes) is summarized. PICsomes were first developed by my research group, and we recently succeeded in controlling the sizes and structural uniformity of the vesicles. Furthermore, the characteristic dynamic nature of PICs was revealed: PICs were found to exhibit reversible association/dissociation and structural transformation. We demonstrated that crosslinking the PIC layers of PICsomes is a powerful method for tuning properties such as stability and permeability. Finally, the potential utility of PICsomes for drug delivery nanocarriers was examined, and their future biomedical application is discussed. © 2013 The Society of Polymer Science, Japan (SPSJ) All rights reserved.

DOI： 10.1038/pj.2013.33

Language：Japanese  

Development of Nano-Sized Polyion Complex Vesicle "PICsomes" and its Application to Bioimaging and Nano-Physiology

Language：Japanese  

汎用性の高い酵素プロドラッグ療法用キャリアを指向した血中滞留型中空ナノ粒子(PICsome)の構築

Language：Japanese  

PIC型ベシクルの特徴を活かした酵素プロドラッグ療法用キャリアの構築

Language：Japanese  

超常磁性酸化鉄微粒子を内包したポリイオンコンプレックス型中空粒子SPIO‐PICsomeの開発と緩和能・腫瘍集積性評価

Language：English   Publishing type：Research paper (other academic)  

SPIO-loaded unilamellar polyion complex vesicles (SPIO-Cy5-PICsomes) as a high relaxivity contrast agent for tumor detection

Language：English   Publishing type：Research paper (scientific journal)  

Anti-HMGB1 antibody attenuates vascular hyperpermeability and promotes wound healing during ischemia-reperfusion injury model in mouse skin

DOI： 10.1016/j.jdermsci.2012.11.481

Language：English   Publishing type：Research paper (other academic)  

We present a microfluidic platform to characterize nanoparticle permeability, which determines the efficiency of nanoparticle-based drug delivery to tumors. We integrated porous membranes that mimic tumor vascular walls into microfluidic devices. Permeation of the nanoparticles through the membranes was studied under control of transmembrane flow, which corresponds to outward flow from blood vessels to tumors in vivo. The obtained results agreed with a theoretical model considering the effect of particle/pore size ratio on the permeation. These results indicate that the device can be a simple model to estimate the permeability of the nanoparticles.

Language：English   Publishing type：Research paper (scientific journal)  

In this study, poly(ethylene glycol) (PEG)-block-polycation/siRNA complexes (PEGylated polyplexes) were wrapped with a hydrated silica, termed "silica nanogelling", in order to enhance their stability and functionality. Silica nanogelling was achieved by polycondensation of soluble silicates onto the surface of PEGylated polyplexes comprising a disulfide cross-linked core. Formation of silica nanogel layer on the PEGylated cross-linked polyplexes was confirmed by particle size increase, surface charge reduction, and elemental analysis of transmission electron micrographs. Silica nanogelling substantially improved polyplex stability against counter polyanion-induced dissociation under non-reductive condition, without compromising the reductive environment-responsive siRNA release triggered by disulfide cleavage. Silica nanogelling significantly enhanced the sequence-specific gene silencing activity of the polyplexes in HeLa cells without associated cytotoxicity, probably due lower endosomal entrapment (or lysosomal degradation) of delivered siRNA. The lower endosomal entrapment of the silica nanogel system could be explained by an accelerated endosomal escape triggered by deprotonated silanol groups in the silica (the proton sponge hypothesis) and/or a modulated intracellular trafficking, possibly via macropinocytosis, as evidenced by the cellular uptake inhibition assay. Henceforth, silica nanogelling of PEGylated siRNA polyplexes is a promising strategy for preparation of stable and functional siRNA delivery vehicles. (C) 2012 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.biomaterials.2012.09.077

Language：English   Publishing type：Research paper (scientific journal)  

The development of organic semiconducting nanowires that act as charge carrier transport pathways in flexible and lightweight nanoelectronics is a major scientific challenge. We report on the fabrication of fullerene nanowires that is universally applicable to its derivatives (pristine C ₆₀, methanofullerenes of C ₆₁ and C ₇₁, and indene C ₆₀ bis-adduct), realized by the single particle nanofabrication technique (SPNT). Nanowires with radii of 811 nmwere formed via a chain polymerization reaction induced by a high-energy ion beam. Fabrication of a poly(3-hexylthiophene) (P3HT): [6,6]-phenyl C ₆₁ butyric acid methyl ester (PC ₆₁BM) bulk heterojunction organic photovoltaic cell including PC ₆₁BM nanowires with precisely-controlled length and density demonstrates how application of this methodology can improve the power conversion efficiency of these inverted cells. The proposed technique provides a versatile platform for the fabrication of continuous and uniform n-type fullerene nanowires towards a wide range of organic electronics applications.

DOI： 10.1038/srep00600

Language：English   Publishing type：Research paper (scientific journal)  

We developed a simple preparation procedure for the protein encapsulated nanoparticle and used the nanoparticle for spatiotemporal activity control of various proteins. We succeeded in the local protein activation within cells by light using the nanoparticle.

DOI： 10.1039/c2cc32718j

Language：English  

Language：Japanese  

In vivoナノリアクターへの展開を指向した酵素封入PICsomeの機能評価

Language：Japanese  

超常磁性酸化鉄微粒子を内包したポリイオンコンプレックス型中空ナノ粒子PICsomeを用いたin vivo MRイメージング

Language：Japanese  

粒径の制御された高分子ベシクルPICsomeの体内動態と生体内イメージング応用

Language：Japanese  

架橋率・サイズの異なるポリイオンコンプレックス型中空粒子(Nano‐PICsome)の基礎物性評価および体内動態評価

Language：Japanese  

インテリジェントDDSキャリアを指向したポリイオンコンプレックス型中空粒子(Nano‐PICsome)の開発

Language：Others  

Formation of polymer vesicles from microdroplets of polyion complex and examination of their physicochemical properties in microfluidic chamber
This paper presents a direct observation of a non-trivial formation process of individual giant polymer vesicles, i.e., direct formation of vesicles from microdroplets of polyion complex (PIC) and the optimum condition for the formation of the PIC vesicles, providing a basis for an efficient mass-production. In addition, encapsulation of guest polymers and their retention within the PIC vesicle are demonstrated as well as modification of property of the PIC membrane by crosslinking of the constituent polymers. All experiments were achieved in a microfluidic chamber which can control solution conditions with keeping targeted objects under the view field of the optical microscope.

Language：Japanese  

ブロック共重合体からなる自己組織化中空粒子PICsomeの開発とin vivo応用

Language：Japanese  

架橋率の異なるポリイオンコンプレックス型中空粒子(Nano‐PICsome)の基礎物性評価と体内動態評価

Language：Japanese  

Enjoy Conferences!

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/smll.201000872

Language：English   Publishing type：Research paper (other academic)  

This paper presents a direct observation of a non-trivial formation process of individual giant polymer vesicles, i.e., direct formation of vesicles from microdroplets of polyion complex (PIC) and the optimum condition for the formation of the PIC vesicles, providing a basis for an efficient mass-production. In addition, encapsulation of guest polymers and their retention within the PIC vesicle are demonstrated as well as modification of property of the PIC membrane by crosslinking of the constituent polymers. All experiments were achieved in a microfluidic chamber which can control solution conditions with keeping targeted objects under the view field of the optical microscope.

Language：English   Publishing type：Research paper (scientific journal)  

Nanoparticle therapeutics are promising platforms for cancer therapy. However, it remains a formidable challenge to assess their distribution and clinical efficacy for therapeutic applications. Here, by using multifunctional polymeric micellar nanocarriers incorporating clinically approved gadolinium (Gd)-based magnetic resonance imaging contrast agents and platinum (Pt) anticancer drugs through reversible metal chelation of Pt, simultaneous imaging and therapy of an orthotopic animal model of intractable human pancreatic tumor was successfully performed without any serious toxicity. The strong tumor contrast enhancement achieved by the micelles correlated with the 24 times increase of r(1) of the Gd chelates, the highest for the formulations using clinically approved Gd chelates reported to date. From the micro-synchrotron radiation X-ray fluorescence spectrometry scanning of the lesions, we confirmed that both the Gd chelates and Pt drugs delivered by the micelles selectively colocalized in the tumor interior. Our study provides new insights for the design of theranostic micelles with high contrast enhancement and site-specific clinical potential. Cancer Res; 70(18); 7031-41. (C)2010 AACR.

DOI： 10.1158/0008-5472.CAN-10-0303

Language：Japanese  

Structural control of nano-/micro-capsules through the simple preparation methods based on macromolecular self-assemblies and their application to biomaterials

Language：Japanese  

Language：Others  

Spontaneous formation of giant unilamellar vesicles from microdroplets of a polyion complex by focused infrared laser irradiation
Spontaneous formation of a giant polymer vesicle from a single micrometer-sized droplet of polyion complex (PIC) of diblock copolymers and its derivative by thermal perturbation, which is achieved by irradiation with a focused infrared laser is presented. The thermal perturbation induces a microphase separation inside of the PIC droplet and the generated water rich phase in the PIC droplet becomes a content of the vesicle and the PIC is deformed into a self-assembled membrane of the vesicle. The size of the giant unilamellar vesicles formed is determined on the basis of the initial size of the PIC droplets. ©2009 IEEE.

DOI： 10.1109/MHS.2009.5352051

Language：English  

Polymeric vesicles assembled by metal complexation as versatile theranostic nanodevices

Language：English   Publishing type：Research paper (other academic)  

Spontaneous formation of a giant polymer vesicle from a single micrometer-sized droplet of polyion complex (PIC) of diblock copolymers and its derivative by thermal perturbation, which is achieved by irradiation with a focused infrared laser is presented. The thermal perturbation induces a microphase separation inside of the PIC droplet and the generated water rich phase in the PIC droplet becomes a content of the vesicle and the PIC is deformed into a self-assembled membrane of the vesicle. The size of the giant unilamellar vesicles formed is determined on the basis of the initial size of the PIC droplets.

DOI： 10.1109/MHS.2009.5352051

Language：Others  

Spontaneous formation of polymer vesicles from microdroplets of polyion complex via microphase separation
This paper presents a new method for the formation of giant polymer vesicles, which utilizes a microphase separation occurring in microdroplets of polyion complex (PIC), and continuous production of the giant polymer vesicles is demonstrated using a microfluidic channel. © 2008 CBMS.

Language：English   Publishing type：Research paper (other academic)  

This paper presents a new method for the formation of giant polymer vesicles, which utilizes a microphase separation occurring in microdroplets of polyion complex (PIC), and continuous production of the giant polymer vesicles is demonstrated using a microfluidic channel.

Language：English   Publishing type：Research paper (scientific journal)  

A series of poly(benzyl ether) dendrimer porphyrins (DPs) (Gn = n-generation dendrimer, n = 1-3) was examined as potential photosensitizers for photodynamic therapy (PDT). Polyion complexes (PICs) between the DPs and poly(ethylene glycol)-block-poly(L-lysine) (PEG-beta-PLL) were formed via an electrostatic interaction between the positively charged poly(L-lysine) (PLL) segment and negatively charged periphery of the DPs. Dynamic light scattering (DLS) measurements and transmission electron microscopy. (TEM) showed that G3 formed a core-shell-type nanocarrier micelle, whereas G1 and G2 formed irregular-shaped nanoparticles with a relatively high polydispersity. The photophysical properties of the DP-loaded PIC nanocarriers strongly depend on the generation of the DPs. In the case of GI and G2, their fluorescence lifetime and oxygen consumption ability were significantly reduced by the formation of the PIC nanocarriers, whereas the G34oaded PIC nanocarrier exhibited almost comparable fluorescence lifetimes and oxygen consumption abilities to the free G3. The incorporation of DPs into PIC nanocarriers resulted in an appreciable increase in the cellular uptake, yet inversely correlated with the generation. Alternatively, the photocytotoxicity of the DPs within the nanocarriers increased with an increase in the generation despite a decrease in the cellular uptake. By correlating the effects of the uptake amount with the photocytotoxicity, the PIC nanocarriers showed remarkable enhancement of the PDT efficacy dependent on the generation of DPs.

DOI： 10.1021/cm071451m

Language：Japanese  

Thermally Rewritable Phosphorescent Paper

Language：English   Publishing type：Research paper (other academic)  

In this study, using thermo-sensitive poly (2-isopropyl-2-oxazoline)s (PiPrOx), we prepared a series of block copolymers (PEtOx-e-PiPrOx). Two different functional groups at both terminal ends were introduced to the block copolymers. We investigated the thermo-sensitive behavior of block copolymers and the effect of their compositions and the end functional groups.

Language：English   Publishing type：Research paper (other academic)  

In this study, we synthesized poly (2-ethyl-2-oxazolines) (PEtOx). And using thermosensitive polymer (poly (2-isopropyl-2-oxazolines) (PiPrOx)), we prepared a series of block copolymers composed of PEtOx and PiPrOx. These copolymers form the aggregates by the hydrophobic interaction near the LCST We investigated the thermosensitive behavior of diblock copolymer (PEtOx (44)-PiPrOx (44)). The aggregates formed at the temperature near the LCST were observed by TEM. We confirmed the aggregates formation responding the temperature.

Language：English   Publishing type：Research paper (other academic)  

A novel type of polymersome formed through a self-assembly of polyion complex of block copolymers was firstly designed as "PICsome". The PICsome can be simply prepared in an aqueous solution via electrostatic interaction between a pair of the oppositely charged block copolymers. A series of copolymers was newly synthesized, and the polymer assemblies were prepared and investigated.

Language：Japanese  

Language：Japanese  

Molecular Design of Nano-scale Catalysts Using Dendrimer Scaffolds

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/ja010426t

Total pages：536   Responsible for pages：p.426-p.433   Language：Japanese   Book type：Scholarly book

Event date： 2020.11

Language：English  

Venue：オンライン開催  

Event date： 2020.11

Language：Japanese  

Venue：オンライン開催  

Event date： 2020.9

Language：Japanese  

Venue：オンライン開催(岩手大学　上田キャンパス開催中止）  

Event date： 2020.9

Language：Japanese  

Venue：オンライン開催(岩手大学　上田キャンパス開催中止）  

Event date： 2020.9

Language：Japanese  

Venue：オンライン開催(岩手大学　上田キャンパス開催中止）  

Event date： 2020.9

Language：Japanese  

Venue：オンライン開催(岩手大学　上田キャンパス開催中止）  

Event date： 2020.9

Language：Japanese  

Venue：オンライン開催  

Event date： 2020.9

Language：Japanese  

Venue：オンライン開催   Country：Japan  

Event date： 2020.8

Language：Japanese  

Venue：神戸学院大学ポートアイランドキャンパス（神戸市中央区）　　＊オンサイトとオンラインの併用  

Event date： 2020.8

Language：Japanese  

Venue：神戸学院大学ポートアイランドキャンパス（神戸市中央区）　　＊オンサイトとオンラインの併用  

Event date： 2020.8

Language：Japanese  

Venue：神戸学院大学ポートアイランドキャンパス（神戸市中央区）　　＊オンサイトとオンラインの併用  

Event date： 2020.8

Language：Japanese  

Venue：神戸学院大学ポートアイランドキャンパス（神戸市中央区）　　＊オンサイトとオンラインの併用  

Event date： 2020.8

Language：English  

Venue：エジプトカイロ（オンライン開催）  

Event date： 2020.7

Language：English  

Venue：（現地開催中止、オンライン開催）  

Event date： 2020.7

Language：English  

Venue：（現地開催中止、オンライン開催）  

Event date： 2020.5

Language：Japanese  

Venue：福岡国際会議場（現地開催中止）  

Event date： 2020.5

Language：Japanese  

Venue：福岡国際会議場（現地開催中止）  

Event date： 2020.1

Language：Japanese  

Venue：崇城大学池田キャンパス・熊本県熊本市  

Event date： 2019.12

Language：English  

Venue：the Taipei International Convention Center(台湾台北市）  

Event date： 2019.12

Language：English  

Venue：the Taipei International Convention Center(台湾台北市）  

Event date： 2019.11

Language：Japanese  

Venue：横浜情報文化センター、横浜市開講記念会館他（横浜市中区）  

Event date： 2019.11

Language：Japanese  

Venue：横浜情報文化センター、横浜市開講記念会館他（横浜市中区）  

Event date： 2019.11

Language：English  

Venue：万国津梁館（沖縄県名護市）  

Event date： 2019.11

Language：English  

Venue：万国津梁館（沖縄県名護市）  

Event date： 2019.11

Language：English  

Venue：万国津梁館（沖縄県名護市）  

Event date： 2019.11

Language：English  

Venue：万国津梁館（沖縄県名護市）  

Event date： 2019.11

Language：English  

Venue：万国津梁館（沖縄県名護市）  

Event date： 2019.10

Language：Japanese  

Venue：船堀タワーホール（東京都江戸川区）  

Event date： 2019.10

Language：Japanese  

Venue：東京工業大学（横浜市緑区）  

Event date： 2019.9

Language：Japanese  

Venue：福井大学（福井県福井市）  

Event date： 2019.9

Language：Japanese  

Venue：福井大学（福井県福井市）  

Event date： 2019.9

Language：Japanese  

Venue：福井大学（福井県福井市）  

Event date： 2019.9

Language：English  

Venue：東北大学片平さくらホール（仙台市青葉区）  

Event date： 2019.9

Language：Japanese  

Venue：東北大学青葉山キャンパス（仙台市青葉区）  

Event date： 2019.9

Language：Japanese  

Venue：東北大学青葉山キャンパス（仙台市青葉区）  

Event date： 2019.7

Language：English  

Venue：北九州国際会議場（北九州市小倉北区）  

Event date： 2019.7

Venue：北九州国際会議場（北九州市小倉北区）  

Event date： 2019.7

Language：Japanese  

Venue：京都市下京区（キャンパスプラザ京都）  

Event date： 2019.6

Language：English  

Venue：神戸国際会議場・神戸国際展示場  

Event date： 2019.6

Language：English  

Venue：浙江大学（中国杭州市）  

Event date： 2019.6

Language：English  

Venue：熊本市中央区（熊本大学工学部）  

Event date： 2019.6

Language：English  

Venue：熊本市中央区（熊本大学工学部）  

Event date： 2019.5 - 2019.6

Language：English  

Venue：Mainz大学（ドイツ　マインツ）  

Event date： 2019.5 - 2019.6

Language：English  

Venue：Mainz大学（ドイツ　マインツ）  

Event date： 2019.5

Language：English  

Venue：Twente大学（オランダ　エンスヘーデ）  

Event date： 2019.5

Language：English  

Venue：Twente大学（オランダ　エンスヘーデ）  

Event date： 2019.3 - 2019.4

Language：English  

Venue：Orange County Convention, Rosen Centre Hotel  

Event date： 2019.3 - 2019.4

Language：English  

Venue：Orange County Convention, Rosen Centre Hotel  

Event date： 2019.3 - 2020.3

Language：English  

Venue：京都市左京区  

Event date： 2019.3 - 2020.3

Language：Japanese  

Venue：京都市左京区  

Language：Japanese  

Venue：ホテル＆リゾーツ別府湾（大分県速見郡日出町）   Country：Japan  

Language：Japanese  

Venue：オンライン  

Language：Japanese  

Venue：北九州国際会議場（北九州市小倉北区）   Country：Japan  

Language：English  

Venue：九州大学馬出キャンパス（福岡市東区）   Country：Japan  

Language：English  

Venue：九州大学馬出キャンパス（福岡市東区）   Country：Japan  

Language：English  

Venue：九州大学馬出キャンパス（福岡市東区）   Country：Japan  

Language：English  

Venue：オンライン  

Language：English  

Venue：Karolinska University Hospital, Sweden   Country：Sweden  

Language：Japanese  

Venue：北海道大学   Country：Japan  

Language：English  

Venue：北海道大学   Country：Japan  

Language：Japanese  

Venue：北海道大学   Country：Japan  

Language：Japanese  

Venue：名古屋大学東山キャンパス(愛知県名古屋市）   Country：Japan  

Language：Japanese  

Venue：ルスツリゾート（北海道留寿都郡）   Country：Japan  

Language：Japanese  

Venue：函館アリーナ、函館市民会館（北海道函館市）   Country：Japan  

Language：English  

Venue：オンライン  

Language：Japanese  

Venue：広島国際会議場（広島県広島市）   Country：Japan  

Language：Japanese  

Venue：東京工業大学すずかけ台キャンパス   Country：Japan  

Language：Japanese  

Venue：理化学研究所　和光事業所   Country：Japan  

Language：Japanese  

Venue：オンライン  

Language：Japanese  

Venue：北海道大学（北海道札幌市）   Country：Japan  

Language：English  

Venue：北海道大学（北海道札幌市）   Country：Japan  

Language：English  

Venue：北海道大学（北海道札幌市）   Country：Japan  

Language：English  

Venue：北海道大学（北海道札幌市）   Country：Japan  

Language：Japanese  

Venue：Gメッセ群馬（群馬県高崎市）   Country：Japan  

Language：Japanese  

Venue：Gメッセ群馬（群馬県高崎市）   Country：Japan  

Language：Japanese  

Venue：北九州国際会議場（福岡県北九州市小倉北区）   Country：Japan  

Language：Japanese  

Venue：北九州国際会議場（福岡県北九州市小倉北区）   Country：Japan  

Language：English  

Venue：World Forum The Hague（オランダ　ハーグ）   Country：Netherlands  

Language：English  

Venue：Czech Technical University（チェコ プラハ）  

Language：English  

Venue：Czech Technical University（チェコ プラハ）  

Language：Japanese  

Venue：大阪公立大学 I-siteなんば   Country：Japan  

Language：Japanese  

Venue：大阪公立大学 I-siteなんば   Country：Japan  

Language：Japanese  

Venue：大阪公立大学 I-siteなんば   Country：Japan  

Language：Japanese  

Venue：東京大学駒場キャンパス（東京都目黒区）   Country：Japan  

Language：Japanese  

Venue：香川大学幸町キャンパス（香川県高松市）   Country：Japan  

Venue：名古屋国際会議場（愛知県名古屋市）   Country：Japan  

Language：English  

Venue：名古屋国際会議場（愛知県名古屋市）   Country：Japan  

Language：English  

Venue：名古屋国際会議場（愛知県名古屋市）   Country：Japan  

Language：English  

Venue：東京大学駒場Ⅱキャンパス（東京都目黒区）   Country：Japan  

Language：English  

Venue：国立京都国際会館   Country：Japan  

Language：English  

Venue：国立京都国際会館   Country：Japan  

Language：Japanese  

Venue：ホテル＆リゾーツ別府湾（大分県速見郡日出町）   Country：Japan  

Language：English  

Venue：Orlando, USA  

Language：English  

Venue：Hawaii Convention Center, Honolulu, Hawaii, USA   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学黒髪キャンパス、熊本   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜市開港記念会館、横浜   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東北大学片平キャンパス多元物質科学研究所、仙台   Country：Japan  

Language：Japanese  

Venue：羽田空港ギャラクシーホール、東京   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学伊都キャンパス WPI-I2CNERホール、福岡   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学（西早稲田キャンパス）、東京   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：出光会館、市原市、千葉   Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Venue：Development of Biomedical Engineering in Vietnam, International University, Ho Chi Minh City,   Country：Viet Nam  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：慶応義塾大学（芝共立キャンパス）、東京   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：すずかけ台ホール、東京工業大学、東京   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：にっしょうかん、長崎市、長崎   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋工業大学、名古屋   Country：Japan  

Language：English  

Venue：札幌市白石区（札幌コンベンションセンター）   Country：Japan  

Language：Japanese  

Venue：札幌市白石区（札幌コンベンションセンター）   Country：Japan  

Language：Japanese  

Venue：札幌市白石区（札幌コンベンションセンター）   Country：Japan  

Language：Japanese  

Venue：北九州市小倉北区（北九州国際会議場）   Country：Japan  

Language：Japanese  

Venue：北九州市小倉北区（北九州国際会議場）   Country：Japan  

Language：English  

Venue：Edinburgh, Scotland, UK(the Edinburgh International Conference Centre)   Country：United Kingdom  

Language：Japanese  

Venue：熊本市中央区（熊本大学工学部）   Country：Japan  

Language：English  

Venue：アメリカカリフォルニア州サンタローザ（Hilton Sonoma Wine Country)   Country：United States  

Language：Japanese  

Venue：茨城県つくばみらい市   Country：Japan  

Language：Japanese  

Venue：茨城県つくばみらい市   Country：Japan  

Language：English  

Venue：韓国釜山市(Dong-A University)   Country：Korea, Republic of  

Language：Japanese  

Venue：熊本大学 大江キャンパス、熊本   Country：Japan  

Language：Japanese  

Venue：横浜市中区（横浜市開港記念会館）   Country：Japan  

Language：English  

Venue：アメリカ合衆国ハワイ州ホノルル（ハワイコンベンションセンター）   Country：United States  

Language：English  

Venue：アメリカ合衆国ハワイ州ホノルル（ハワイコンベンションセンター）   Country：United States  

Language：English  

Venue：アメリカ合衆国ハワイ州ホノルル（ハワイコンベンションセンター）   Country：United States  

Language：English  

Venue：アメリカ合衆国ハワイ州ホノルル（ハワイコンベンションセンター）   Country：United States  

Language：Japanese  

Venue：同志社大学京田辺キャンパス、京田辺市   Country：Japan  

Language：English   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：華中科技大学, 武漢   Country：China  

Language：Japanese  

Venue：神戸国際会議場・展示場（神戸市中央区）   Country：Japan  

Language：Japanese  

Venue：神戸国際会議場・展示場（神戸市中央区）   Country：Japan  

Language：Japanese  

Venue：神戸国際会議場・展示場（神戸市中央区）   Country：Japan  

Language：Japanese  

Venue：神戸国際会議場・展示場（神戸市中央区）   Country：Japan  

Language：Japanese  

Venue：神戸国際会議場・展示場（神戸市中央区）   Country：Japan  

Language：English  

Venue：Centro Congressi Hotel Quattrotorri (Perugia Italy)   Country：Italy  

Language：Japanese  

Venue：グランシップ（静岡市駿河区）   Country：Japan  

Language：Japanese  

Venue：グランシップ（静岡市駿河区）   Country：Japan  

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：グランシップ（静岡市駿河区）   Country：Japan  

Language：Japanese  

Venue：北九州国際会議場（北九州市小倉北区）   Country：Japan  

Language：Japanese  

Venue：北九州国際会議場（北九州市小倉北区）   Country：Japan  

Language：Japanese  

Venue：北九州国際会議場（北九州市小倉北区）   Country：Japan  

Language：English   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：Westfälische Wilhelms-Universität Münster, Münster   Country：Germany  

Language：English   Presentation type：Oral presentation (general)  

Venue：RWTH Aachen University (Aachen Germany)   Country：Germany  

Language：Japanese  

Venue：石川県立音楽堂、もてなしドーム地下イベント広場   Country：Japan  

Language：Japanese  

Venue：横浜市神奈川区（神奈川大学 横浜キャンパス）   Country：Japan  

Language：Japanese  

Venue：熊本大学薬学部   Country：Japan  

Language：English  

Venue：中国武漢（ Hilton Wuhan Optics Valley）   Country：China  

Language：English   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：Insitut Teknologi Bandung (ITB), Bandung   Country：Indonesia  

Language：English  

Venue：Grand Royal Panghegar Hotel & Convention（インドネシア バンドン）   Country：Indonesia  

Language：Japanese  

Venue：菊南温泉ユウベルホテル（熊本市北区）   Country：Japan  

Language：Japanese  

Venue：福岡市博多区（福岡国際会議場）   Country：Japan  

Language：Japanese  

Venue：鳥取県鳥取市（温泉旅館 丸茂　会議室）   Country：Japan  

Language：English  

Venue：福岡市博多区（福岡国際会議場）   Country：Japan  

Language：English  

Venue：福岡市博多区（福岡国際会議場）   Country：Japan  

Language：Japanese  

Venue：横浜市港区（慶應義塾大学　日吉キャンパス）   Country：Japan  

Language：English  

Venue：横浜市港区（慶應義塾大学　日吉キャンパス）   Country：Japan  

Language：English   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：福岡市西区（九州大学　伊都キャンパス）   Country：Japan