Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Akihiro Kishimura Last modified date:2021.06.11

Associate Professor / Department of Applied Chemistry / Faculty of Engineering

1. Kaneko, Ryosuke; Kawamura, Masumi; Kishimura, Akihiro; Mori, Takeshi; Katayama, Yoshiki, Effect of a Chloroacetyl Modification on the Suppression of Dissociation of a Fluorescent Molecule from Cells for Antigen- Specific Cell Staining, ANALYTICAL SCIENCES, 10.2116/analsci.20SCN03, 37, 3, 529-532, 2021.03.
2. Beob Soo Kim, Mitsuru Naito, Hiroyuki Chaya, Mao Hori, Kotaro Hayashi, Hyun Su Min, Yu Yi, Hyun Jin Kim, Tetsuya Nagata, Yasutaka Anraku, Akihiro Kishimura, Kazunori Kataoka, and Kanjiro Miyata, Noncovalent Stabilization of Vesicular Polyion Complexes with Chemically Modified/Single-Stranded Oligonucleotides and PEG-b-guanidinylated Polypeptides for Intracavity Encapsulation of Effector Enzymes Aimed at Cooperative Gene Knockdown, Biomacromolecules,, 2020.09, 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..
3. Beob Soo Kim, Mitsuru Naito, Rimpei Kamegawa, Hyun Jin Kim, Ryo Iizuka, Takashi Funatsu, Shingo Ueno, Takanori Ichiki, Akihiro Kishimura and Kanjiro Miyata, Photo-reactive oligodeoxynucleotide-embedded nanovesicles (PROsomes) with switchable stability for efficient cellular uptake and gene knockdown, CHEMICAL COMMUNICATIONS, 10.1039/d0cc01750g, 56, 66, 9477-9480, 2020.08.
4. Takuma Yoshikawa, Khanh Quoc Phan, Hiroshi Tagawa, Koichi Sasaki, Haitao Feng, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, Modification of nitric oxide donors onto a monoclonal antibody boosts accumulation in solid tumors, International Journal of Pharmaceutics, 10.1016/j.ijpharm.2020.119352, 583, 2020.06, 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..
5. Koichi Sasaki, Minori Harada, Yoshiki Miyashita, Hiroshi Tagawa, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, Fc-binding antibody-recruiting molecules exploit endogenous antibodies for anti-tumor immune responses, Chemical Science, 10.1039/d0sc00017e, 11, 12, 3208-3214, 2020.03, 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..
6. Takanobu Nobori, Masumi Kawamura, Ryosuke Yoshida, Taisei Joichi, Kenta Kamino, Akihiro Kishimura, Eishi Baba, Takeshi Mori, Yoshiki Katayama, Fluorescence Signal Amplification by Using β-Galactosidase for Flow Cytometry; Advantages of an Endogenous Activity-Free Enzyme, Analytical chemistry, 10.1021/acs.analchem.9b04471, 92, 4, 3069-3076, 2020.02, 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..
7. Hiroko Nagai, Wataru Hatanaka, Masayoshi Matsuda, Akihiro Kishimura, Yoshiki Katayama, Takeshi Mori, Folate receptor-specific cell-cell adhesion by using a folate-modified peptide-based anchor, Journal of Biomaterials Science, Polymer Edition, 10.1080/09205063.2019.1616975, 30, 11, 983-993, 2019.07, 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..
8. Takuma Yoshikawa, Yukina Mori, Haitao Feng, Khanh Quoc Phan, Akihiro Kishimura, Jeong Hun Kang, Takeshi Mori, Yoshiki Katayama, Rapid and continuous accumulation of nitric oxide-releasing liposomes in tumors to augment the enhanced permeability and retention (EPR) effect, International Journal of Pharmaceutics, 10.1016/j.ijpharm.2019.05.043, 565, 481-487, 2019.06, 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..
9. Beob Soo Kim, Sayan Chuanoi, Tomoya Suma, Yasutaka Anraku, Kotaro Hayashi, Mitsuru Naito, Hyun Jin Kim, Ick Chan Kwon, Kanjiro Miyata, Akihiro Kishimura, Kazunori Kataoka, 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, Journal of the American Chemical Society, 10.1021/jacs.8b13641, 141, 8, 3699-3709, 2019.02, 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..
10. Khadijah Zai, Narumi Ishihara, Hiroyuki Oguchi, Masato Hirota, Akihiro Kishimura, Takeshi Mori, Koji Hase, Yoshiki Katayama, Regulation of inflammatory response of macrophages and induction of regulatory T cells by using retinoic acid-loaded nanostructured lipid carrier, Journal of Biomaterials Science, Polymer Edition, 10.1080/09205063.2018.1493671, 30, 1, 1-11, 2019.01, 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-κB signaling as well as via enhancing the production of anti-inflammatory cytokines. Moreover, NLC-RA enhanced differentiation of naïve 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. (Figure presented.)..
11. Wataru Hatanaka, Hiroki Takeuchi, Minaho Koga, Taka Aki Ryujin, Akihiro Kishimura, Yoshiki Katayama, Shinya Tsukiji, Takeshi Mori, Synthesis of transmembrane molecules by click chemistry, Chemistry Letters, 10.1246/cl.190009, 48, 5, 433-436, 2019.01, 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..
12. Masayuki Yokoyama, Kouichi Shiraishi, Akihiro Kishimura, Glassware cleaning, Drug Delivery System, 10.2745/dds.34.213, 34, 3, 213-215, 2019.01.
13. Mao Hori, Horacio Cabral, Kazuko Toh, Akihiro Kishimura, Kazunori Kataoka, Robust Polyion Complex Vesicles (PICsomes) under Physiological Conditions Reinforced by Multiple Hydrogen Bond Formation Derived by Guanidinium Groups, Biomacromolecules, 10.1021/acs.biomac.8b01097, 19, 10, 4113-4121, 2018.10, 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..
14. Masamitsu Suhara, Yutaka Miura, Horacio Cabral, Daisuke Akagi, Yasutaka Anraku, Akihiro Kishimura, Masaya Sano, Takuya Miyazaki, Noriko Nakamura, Ayako Nishiyama, Kazunori Kataoka, Hiroyuki Koyama, Katsuyuki Hoshina, Targeting ability of self-assembled nanomedicines in rat acute limb ischemia model is affected by size, Journal of Controlled Release, 10.1016/j.jconrel.2018.07.049, 286, 394-401, 2018.09, 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..
15. Khadijah Zai, Masato Hirota, Takahiro Yamada, Narumi Ishihara, Takeshi Mori, Akihiro Kishimura, Koichiro Suzuki, Koji Hase, Yoshiki Katayama, Therapeutic effect of vitamin D3-containing nanostructured lipid carriers on inflammatory bowel disease, Journal of Controlled Release, 10.1016/j.jconrel.2018.07.019, 286, 94-102, 2018.09, The active form of vitamin D3, 1,25(OH)2D3 has been found to exert multiple effects on the suppression of progression of inflammatory bowel disease (IBD). Vitamin D3 has been gathering attention as a therapy for IBD. However, the clinical trials conducted to date revealed that a relatively high dosage of vitamin D3 was required to see a significant therapeutic effect. Thus, effective formulation and delivery of vitamin D3 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)2D3 for colonic delivery via oral administration. The optimized fabrication procedure enabled the incorporation of 1,25(OH)2D3 in the NLC by minimizing the destruction of chemically unstable 1,25(OH)2D3. The obtained NLCs orally delivered 1,25(OH)2D3 to the colon in mice and maintained a high concentration of 1,25(OH)2D3 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)2D3 may be an alternative treatment for IBD therapy..
16. Hikari Sato, Elnaz Nakhaei, Takahito Kawano, Masaharu Murata, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, Ligand-Mediated Coating of Liposomes with Human Serum Albumin, Langmuir, 10.1021/acs.langmuir.7b04024, 34, 6, 2324-2331, 2018.02, 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..
17. Martin J. Hollamby, Catherine F. Smith, Melanie M. Britton, Ashleigh E. Danks, Zoe Schnepp, Isabelle Grillo, Brian R. Pauw, Akihiro Kishimura, Takashi Nakanishi, The aggregation of an alkyl-C60 derivative as a function of concentration, temperature and solvent type, Physical Chemistry Chemical Physics, 10.1039/c7cp06348b, 20, 5, 3373-3380, 2018.02, 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..
18. Elnaz Nakhaei, Ko Takehara, Hikari Sato, Khadijah Zai, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, A dual alkylated peptide-ligand enhances affinity to human serum albumin, analytical sciences, 10.2116/analsci.17P614, 34, 4, 501-504, 2018.01, 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..
19. Koichi Sasaki, Yoshiki Miyashita, Daisuke Asai, Daiki Funamoto, Kazuki Sato, Yoko Yamaguchi, Yuji Mishima, Tadafumi Iino, Shigeo Takaishi, Jun Nagano, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, A peptide inhibitor of antibody-dependent cell-mediated cytotoxicity against EGFR/folate receptor-α double positive cells, MedChemComm, 10.1039/c8md00010g, 9, 5, 783-788, 2018.01, 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..
20. Takanobu Nobori, Kenta Tosaka, Akira Kawamura, Taisei Joichi, Kenta Kamino, Akihiro Kishimura, Eishi Baba, Takeshi Mori, Yoshiki Katayama, Alkaline Phosphatase-Catalyzed Amplification of a Fluorescence Signal for Flow Cytometry, Analytical Chemistry, 10.1021/acs.analchem.7b03893, 90, 2, 1059-1062, 2018.01, 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..
21. Hikari Sato, Yoshiki Miyashita, Koichi Sasaki, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, Non-covalent coating of liposome surface with igg through its constant region, Chemistry Letters, 10.1246/cl.180181, 47, 6, 770-772, 2018.01, 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 Fcγ receptors (FcγRs) 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..
22. Khadijah Zai, Kazuki Yuzuriha, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, Preparation of complexes between ovalbumin nanoparticles and retinoic acid for efficient induction of Tolerogenic dendritic cells, analytical sciences, 10.2116/analsci.18P252, 34, 11, 1243-1248, 2018.01, 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..
23. Omer F. Mutaf, Yasutaka Anraku, Akihiro Kishimura, Kazunori Kataoka, Unilamellar polyion complex vesicles (PICsomes) with tunable permeabilities for macromolecular solutes with different shapes and sizes, Polymer, 10.1016/j.polymer.2017.10.062, 133, 1-7, 2017.12, 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..
24. Yuta Nakamura, Hikari Sato, Takanobu Nobori, Hotaru Matsumoto, Shoko Toyama, Tomohiro Shuno, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, Modification of ligands for serum albumin on polyethyleneimine to stabilize polyplexes in gene delivery, Journal of Biomaterials Science, Polymer Edition, 10.1080/09205063.2017.1328730, 28, 13, 1382-1393, 2017.09, 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..
25. Hengmin Tang, Takeshi Mori, Yoshiki Katayama, Akihiro Kishimura, Development of Enzyme Loaded Polyion Complex Vesicle (PICsome): Thermal Stability of Enzyme in PICsome compartment and Effect of Co-Encapsulation of Dextran on Enzyme Activity., Macromolecular Bioscience, 10.1002/mabi.201600542, 2017.05.
26. Akihiro Kishimura, Akinori Goto, Ping-Shan Lai, Kazunori Kataoka, Facile Preparation of Delivery Platform of Water-Soluble Low-Molecular-Weight Drugs Based on Polyion Complex Vesicle (PICsome) Encapsulating Mesoporous Silica Nanoparticle, ACS Biomaterials Science & Engineering, 10.1021/acsbiomaterials.6b00562, 2017.03.
27. Wataru Hatanaka, Akihiro Kishimura, Yoshiki Katayama, Takeshi Mori, Use of Membrane Potential to Achieve Transmembrane Modification with an Artificial Receptor, BIOCONJUGATE CHEMISTRY, 10.1021/acs.bioconjchem.6b00449, 28, 2, 296-301, 2017.02.
28. Elnaz Nakhaei, Chan Woo Kim, Daiki Funamoto, Hikari Sato, Yuta Nakamura, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, Design of a ligand for cancer imaging with long blood circulation and an enhanced accumulation ability in tumors, MedChemComm, 10.1039/c7md00102a, 8, 6, 1190-1195, 2017.01, 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..
29. Cuicui Li, Masafumi Takeo, Masayoshi Matsuda, Hiroko Nagai, Sun Xizheng, Wataru Hatanaka, Akihiro Kishimura, Hiroyuki Inoue, Kenzaburo Tani, Takeshi Mori, Yoshiki Katayama, Facilitating the presentation of antigen peptides on dendritic cells for cancer immunotherapy using a polymer-based synthetic receptor, MedChemComm, 10.1039/c7md00188f, 8, 6, 1207-1212, 2017.01, 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..
30. Md Zahangir Hosain, Kazuki Yuzuriha, Khadijah, Masafumi Takeo, Akihiro Kishimura, Yoshihiko Murakami, Takeshi Mori, Yoshiki Katayama, Synergic modulation of the inflammatory state of macrophages utilizing anti-oxidant and phosphatidylserine-containing polymer-lipid hybrid nanoparticles, MedChemComm, 10.1039/c7md00174f, 8, 7, 1514-1520, 2017, 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 α-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 α-tocopherol is an antioxidant that neutralizes ROS. We found that PS-containing (PS-PLNPs) and PS plus α-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 α-tocopherol. This synergic action of PST-PLNPs reduced NO and pro-inflammatory cytokine (IL-6) production and increased anti-inflammatory cytokine (TGF-β1) production when incubated with activated macrophages. Thus, these self-filling biodegradable polymer-lipid hybrid nanoparticles (PST-PLNPs) containing anti-oxidant 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..
31. Akihiro Kishimura, Naoki Sasaki, Kae Sato, A Membrane-Integrated Microfluidic Device to Study Permeation of Nanoparticles through Straight Micropores toward Rational Design of Nanomedicines, Analytical Science, 10.2116/analsci.32.1307, 32, 12, 1307-1314, 2016.12.
32. Takuma Yoshikawa, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, Encapsulation of a nitric oxide donor into a liposome to boost the enhanced permeation and retention (EPR) effect, MEDCHEMCOMM, 10.1039/c6md00614k, 8, 2, 415-421, 2016.12.
33. Kenshiro Naoyama, Takeshi Mori, Yoshiki Katayama, Akihiro Kishimura, Fabrication of Dendrimer-based Polyion Complex Submicrometer-scaled Structures with Enhanced Stability under Physiological Conditions., Macromolecular Rapid Communications, 10.1002/marc.201600171, 37, 13, 1087-1093, 2016.05.
34. Akihiro Kishimura, Yutaka Miura, Hiroyuki Koyama, Adequately-Sized Nanocarriers Allow Sustained Targeted Drug Delivery to Neointimal Lesions in Rat Arteries., Molecular Pharmaceutics (ACS), 10.1021/acs.molpharmaceut.6b00219, 13, 6, 2108-2116, 2016.05.
35. Takahiro Nomoto, Peng Mi, Kazuko Toh, Yu Matsumoto, Yuji Morimoto, Akihiro Kishimura, Nobuhiro Nishiyama, Kazunori Kataoka, Calcium phosphate-based organic-inorganic hybrid nanocarriers with pH-responsive on/off switch for photodynamic therapy, BIOMATERIALS SCIENCE, 10.1039/c6bm00011h, 4, 5, 826-838, 2016.03.
36. Kim, Chan Woo, Asai, Daisuke, Kang, Jeong-Hun, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, Reversal of efflux of an anticancer drug in human drug-resistant breast cancer cells by inhibition of protein kinase C alpha (PKC alpha) activity, TUMOR BIOLOGY, 10.1007/s13277-015-3963-4, 37, 2, 1901-1908, 2016.02.
37. Md Zahangir Hosain, Takeshi Mori, Akihiro Kishimura, Yoshiki Katayama, Synergy between phenotypic modulation and ROS neutralization in reduction of inflammatory response of hypoxic microglia by using phosphatidylserine and antioxidant containing liposomes, Journal of Biomaterials Science, Polymer Edition, 10.1080/09205063.2015.1125565, 27, 3, 290-302, 2016.02, 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 α-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 α-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 α-tocopherol. This synergic action of PST-liposomes was illustrated in their ability, when incubated with microglia, to reduce NO and pro-inflammatory cytokine (TNF-α) production and increase anti-inflammatory cytokine (TGF-β1) 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..
38. Akihiro Kishimura, Systemically Injectable Enzyme-loaded Polyion Complex Vesicles (PICsomes) as in vivo Nanoreactors Working in Tumor., Angewandte Chemie International Edition, 10.1002/anie.201508339, 55, 560-565, 2016.01, 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 cross- linked b-galactosidase-loaded PICsomes (beta-gal@PICsomes) selectively accumulated in the tumor tissue of mice. Moreover, a model prodrug, HMDER-betaGal, was successfully converted into a highly fluorescent product, HMDER, at the tumor site, even 4days 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..
39. Akihiro Kishimura, An emerging material “PICsome”
A hot zone between “PEG” and “PEG”, Drug Delivery System, 10.2745/dds.31.308, 31, 4, 308-319, 2016.01, 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..
40. Purnima Kumar, Md Zahangir Hosain, Jeong Hun Kang, Masafumi Takeo, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, Suppression of atopic dermatitis in mice model by reducing inflammation utilizing phosphatidylserine-coated biodegradable microparticles, Journal of Biomaterials Science, Polymer Edition, 10.1080/09205063.2015.1100844, 26, 18, 1465-1474, 2015.12, 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 12 days. The mice showed significant reduction in the development of AD symptoms comparing with the mice treated with the PC-coated microparticle..
41. Akihiro Kishimura, Induction of Secondary Structure through Micellization of an Oppositely Charged Pair of Homochiral Block- and Homopolypeptides in an Aqueous Medium, Macromol. Rapid Commun, 10.1002/marc.201500368, 2015.08.
42. Kai Li, Hikari Sato, Chan Woo Kim, Yuta Nakamura, Guo Xi Zhao, Daiki Funamoto, Takanobu Nobori, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, Tumor accumulation of protein kinase-responsive gene carrier/DNA polyplex stabilized by alkanethiol for intravenous injection, Journal of Biomaterials Science, Polymer Edition, 10.1080/09205063.2015.1054922, 26, 11, 657-668, 2015.07, 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%-modification of PLLs ε-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..
43. Akihiro Kishimura, Density-tunable conjugation of cyclic RGD ligands with polyion complex vesicles for the neovascular imaging of orthotopic glioblastomas, SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS, 10.1088/1468-6996/16/3/035004, 16, 3, 2015.06.
44. Masafumi Takeo, Cuicui Li, Masayoshi Matsuda, Hiroko Nagai, Wataru Hatanaka, Tatsuhiro Yamamoto, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, Optimum design of amphiphilic polymers bearing hydrophobic groups for both cell surface ligand presentation and intercellular cross-linking, Journal of Biomaterials Science, Polymer Edition, 10.1080/09205063.2015.1007414, 26, 6, 353-368, 2015.04, 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..
45. Eun Kyung Lee, Chan Woo Kim, Hiroyuki Kawanami, Akihiro Kishimura, Takuro Niidome, Takeshi Mori, Yoshiki Katayama, Utilization of a PNA-peptide conjugate to induce a cancer protease-responsive RNAi effect, RSC Advances, 10.1039/c5ra17737e, 5, 104, 85816-85821, 2015.01, 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..
46. Masayoshi Matsuda, Wataru Hatanaka, Masafumi Takeo, Chan Woo Kim, Takuro Niidome, Tatsuhiro Yamamoto, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, Short peptide motifs for long-lasting anchoring to the cell surface, Bioconjugate Chemistry, 10.1021/bc500465j, 25, 12, 2134-2143, 2014.12, 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-ε-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. (Figure Presented)..
47. Akihiro Kishimura, Fabrication of polyion complex vesicles with enhanced salt and temperature resistance and their potential applications as enzymatic nanoreactors., American Chemical Society, 10.1021/bm500127g, 15, 7, 2389-2397, 2014, 2014.07.
48. Horacio Cabral, Kanjiro Miyata, Akihiro Kishimura, Nanodevices for studying nano-pathophysiology, Advanced Drug Delivery Reviews, 10.1016/j.addr.2014.06.003, 74, 35-52, 2014.07, 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..
49. Akihiro Kishimura, A fluorescent polyion complex nanoparticle that incorporates an internal standard for quantitative analysis of protein kinase activity, Bioconjugate Chem., 10.1021/bc500142, 25, 5, 869-872, 2014.05.
50. Takanobu Nobori, Shujiro Shiosaki, Takeshi Mori, Riki Toita, Chan Woo Kim, Yuta Nakamura, Akihiro Kishimura, Takuro Niidome, Yoshiki Katayama, Fluorescent polyion complex nanoparticle that incorporates an internal standard for quantitative analysis of protein kinase activity, Bioconjugate Chemistry, 10.1021/bc500142j, 25, 5, 869-872, 2014.05, 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..
51. Arie Wibowo, Kensuke Osada, Hiroyuki Matsuda, Yasutaka Anraku, Haruko Hirose, Akihiro Kishimura, Kazunori Kataoka, Morphology control in water of polyion complex nanoarchitectures of double-hydrophilic charged block copolymers through composition tuning and thermal treatment, Macromolecules, 10.1021/ma500314d, 47, 9, 3086-3092, 2014.05, 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 (fPEG) in the obtained PICs. Accordingly, the variation in fPEG 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 PIC domains was found at elevated temperature (70 °C), which, by lowering temperature, reversibly transformed to cylindrical PIC network apparently with connected aqueous channel in mesoscopic scale..
52. Akihiro Kishimura, Morphology Control in Water of Polyion Complex Nanoarchitectures of Double-Hydrophilic Charged Block Copolymers through Composition Tuning and Thermal Treatment. , American Chemical Society, 10.1021/ma500314d , 47, 9, 3086-3092, 2014, 2014.04.
53. Daisuke Kokuryo, Yasutaka Anraku, Akihiro Kishimura, Sayaka Tanaka, Mitsunobu R. Kano, Jeff Kershaw, Nobuhiro Nishiyama, Tsuneo Saga, Ichio Aoki, Kazunori Kataoka, Erratum
SPIO-PICsome: Development of a highly sensitive and stealth-capable MRI nano-agent for tumor detection using SPIO-loaded unilamellar polyion complex vesicles (PICsomes) (Journal of Controlled Release (2013) 169 (220-227)), Journal of Controlled Release, 10.1016/j.jconrel.2014.01.021, 178, 1, 2014.03.
54. Guo Xi Zhao, Hiroyuki Tanaka, Chan Woo Kim, Kai Li, Daiki Funamoto, Takanobu Nobori, Yuta Nakamura, Takuro Niidome, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, Histidinylated poly-L-lysine-based vectors for cancer-specific gene expression via enhancing the endosomal escape, Journal of Biomaterials Science, Polymer Edition, 10.1080/09205063.2013.879562, 25, 5, 519-534, 2014.03, 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 Cα (PKCα), 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 PKCα-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..
55. Kyohei Tobinaga, Cuicui Li, Masafumi Takeo, Masayoshi Matsuda, Hiroko Nagai, Takuro Niidome, Tatsuhiro Yamamoto, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, Rapid and serum-insensitive endocytotic delivery of proteins using biotinylated polymers attached via multivalent hydrophobic anchors, Journal of Controlled Release, 10.1016/j.jconrel.2013.12.024, 177, 1, 27-33, 2014.03, 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% 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..
56. Christopher V. Synatschke, Takahiro Nomoto, Horacio Cabral, Melanie Förtsch, Kazuko Toh, Yu Matsumoto, Kozo Miyazaki, Andreas Hanisch, Felix H. Schacher, Akihiro Kishimura, Nobuhiro Nishiyama, Axel H.E. Müller, Kazunori Kataoka, Multicompartment micelles with adjustable poly(ethylene glycol) shell for efficient in vivo photodynamic therapy, ACS Nano, 10.1021/nn4028294, 8, 2, 1161-1172, 2014.02, 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..
57. Sayan Chuanoi, Akihiro Kishimura, Wen Fei Dong, Yasutaka Anraku, Yuichi Yamasaki, Kazunori Kataoka, Structural factors directing nanosized polyion complex vesicles (Nano-PICsomes) to form a pair of block aniomer/homo catiomers
Studies on the aniomer segment length and the catiomer side-chain structure, Polymer Journal, 10.1038/pj.2013.82, 46, 2, 130-135, 2014.02, 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%, is required for the selective formation of Nano-PICsomes, whereas polymer combinations with f PEG >10% 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..
58. Hikari Sato, Yuta Nakamura, Elnaz Nakhaei, Daiki Funamoto, Chan Woo Kim, Tatsuhiro Yamamoto, Akihiro Kishimura, Takeshi Mori, Yoshiki Katayama, A liposome reversibly coated with serum albumin, Chemistry Letters, 10.1246/cl.140432, 43, 9, 1481-1483, 2014.01, 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..
59. Peng Mi, Daisuke Kokuryo, Horacio Cabral, Michiaki Kumagai, Takahiro Nomoto, Ichio Aoki, Yasuko Terada, Akihiro Kishimura, Nobuhiro Nishiyama, Kazunori Kataoka, Hydrothermally synthesized PEGylated calcium phosphate nanoparticles incorporating Gd-DTPA for contrast enhanced MRI diagnosis of solid tumors, Journal of Controlled Release, 10.1016/j.jconrel.2013.10.038, 174, 1, 63-71, 2014.01, Organic-inorganic hybrid nanoparticles with calcium phosphate (CaP) core and PEGylated shell were developed to incorporate magnetic 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 nanoparticles with a z-average hydrodynamic diameter about 80 nm, neutral surface ξ-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..
60. D. Sueyoshi, Akihiro Kishimura, H. Oana, Y. Anraku, M. Takai, M. Washizu, K. Kataoka, Microchannel-assisted preparation of polyion complex vesicles and real-time observation of their dynamic responses to external electric fields, 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014, 1882-1884, 2014, 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..
61. Akihiro Kishimura, Polyion complex vesicles for photo-induced intracellular delivery of amphiphilic photosensitizer., J. Am. Chem. Soc., 10.1021/ja406992w, 136, 1, 157-163, 2014, 2013.11.
62. Akihiro Kishimura, Development of polyion complex vesicles (PICsomes) from block copolymers for biomedical applications, Polymer Journal, 10.1038/pj.2013.33, 45, 9, 892-897, 2013.09, 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..
63. Hidehiro Oana, Mutsuki Morinaga, Akihiro Kishimura, Kazunori Kataoka, Masao Washizu, Direct formation of giant unilamellar vesicles from microparticles of polyion complexes and investigation of their properties using a microfluidic chamber, Soft Matter, 10.1039/c3sm00089c, 9, 22, 5448-5458, 2013.06, 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..
64. N. Sasaki, M. Tatanou, Y. Anraku, Akihiro Kishimura, K. Kataoka, K. Sato, Characterization of nanoparticle permeability on a membrane-integrated microfluidic device, 17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013 17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013, 3, 1818-1820, 2013.01, 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..
65. Yasutaka Anraku, Akihiro Kishimura, Yuichi Yamasaki, Kazunori Kataoka, Living unimodal growth of polyion complex vesicles via two-dimensional supramolecular polymerization, Journal of the American Chemical Society, 10.1021/ja3096587, 135, 4, 1423-1429, 2013.01, 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..
66. Daisuke Kokuryo, Yasutaka Anraku, Akihiro Kishimura, Sayaka Tanaka, Mitsunobu R. Kano, Jeff Kershaw, Nobuhiro Nishiyama, Tsuneo Saga, Ichio Aoki, Kazunori Kataoka, SPIO-PICsome
Development of a highly sensitive and stealth-capable MRI nano-agent for tumor detection using SPIO-loaded unilamellar polyion complex vesicles (PICsomes), Journal of Controlled Release, 10.1016/j.jconrel.2013.03.016, 169, 3, 220-227, 2013.01, 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 (r2) of the SPIO-Cy5-PICsomes (r2 = 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 mm3) 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..
67. Noha Gouda, Kanjiro Miyata, R. James Christie, Tomoya Suma, Akihiro Kishimura, Shigeto Fukushima, Takahiro Nomoto, Xueying Liu, Nobuhiro Nishiyama, Kazunori Kataoka, Silica nanogelling of environment-responsive PEGylated polyplexes for enhanced stability and intracellular delivery of siRNA, Biomaterials, 10.1016/j.biomaterials.2012.09.077, 34, 2, 562-570, 2013.01, 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..
68. Yuta Maeyoshi, Akinori Saeki, Shotaro Suwa, Masaaki Omichi, Hiromi Marui, Atsushi Asano, Satoshi Tsukuda, Masaki Sugimoto, Akihiro Kishimura, Kazunori Kataoka, Shu Seki, Fullerene nanowires as a versatile platform for organic electronics, Scientific reports, 10.1038/srep00600, 2, 2012.09, 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..
69. Kensuke Osada, Horacio Cabral, Yuki Mochida, Sangeun Lee, Kazuya Nagata, Tetsuya Matsuura, Megumi Yamamoto, Yasutaka Anraku, Akihiro Kishimura, Nobuhiro Nishiyama, Kazunori Kataoka, Bioactive polymeric metallosomes self-assembled through block copolymer-metal complexation, Journal of the American Chemical Society, 10.1021/ja304615y, 134, 32, 13172-13175, 2012.08, Spontaneous formation of polymeric metallosomes with uniform size (∼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 ω-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 α-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..
70. Shuhei Murayama, Baowei Su, Kohki Okabe, Akihiro Kishimura, Kensuke Osada, Masayuki Miura, Takashi Funatsu, Kazunori Kataoka, Masaru Kato, NanoPARCEL
A method for controlling cellular behavior with external light, Chemical Communications, 10.1039/c2cc32718j, 48, 67, 8380-8382, 2012.08, 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..
71. Yasutaka Anraku, Akihiro Kishimura, Atsushi Kobayashi, Makoto Oba, Kazunori Kataoka, Size-controlled long-circulating PICsome as a ruler to measure critical cut-off disposition size into normal and tumor tissues, Chemical Communications, 10.1039/c1cc11465d, 47, 21, 6054-6056, 2011.06, 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..
72. Kosuke Okeyoshi, Daisuke Suzuki, Akihiro Kishimura, Ryo Yoshida, Photoinduced hydrogen-generating nanogel systems, Small, 10.1002/smll.201000872, 7, 3, 311-315, 2011.02, Photoinduced hydrogen nanogenerators are prepared by closely integrating sensitizer and catalyst in a nanogel network. The nanogenerators operate an internal electronic transmission circuit by coordinating the internal sensitizer and catalyst. This nanomaterial could be useful as an artificial photosynthetic system for solar-energy conversion..
73. H. Oana, M. Morinaga, Akihiro Kishimura, M. Gel, K. Kataoka, M. Washizu, Formation of polymer vesicles from microdroplets of polyion complex and examination of their physicochemical properties in microfluidic chamber, 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011, MicroTAS 2011 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011, MicroTAS 2011, 3, 1588-1590, 2011, 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..
74. Sachiko Kaida, Horacio Cabral, Michiaki Kumagai, Akihiro Kishimura, Yasuko Terada, Masaki Sekino, Ichio Aoki, Nobuhiro Nishiyama, Toru Tani, Kazunori Kataoka, Visible drug delivery by supramolecular nanocarriers directing to single-platformed diagnosis and therapy of pancreatic tumor model, Cancer Research, 10.1158/0008-5472.CAN-10-0303, 70, 18, 7031-7041, 2010.09, 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 r1 of the Gd chelates, the highest for the formulations using clinically approved Gd chelates reported to date. From the microsynchrotron 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..
75. Yasutaka Anraku, Akihiro Kishimura, Makoto Oba, Yuichi Yamasaki, Kazunori Kataoka, Spontaneous formation of nanosized unilamellar polyion complex vesicles with tunable size and properties, Journal of the American Chemical Society, 10.1021/ja908350e, 132, 5, 1631-1636, 2010.02, 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..
76. Hidehiro Oana, Akihiro Kishimura, Kei Yonehara, Yuichi Yamasaki, Masao Washizu, Kazunori Kataoka, Spontaneous formation of giant unilamellar vesicles from microdroplets of a polyion complex by thermally induced phase separation, Angewandte Chemie - International Edition, 10.1002/anie.200900721, 48, 25, 4613-4616, 2009.06, 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..
77. Wen Fei Dong, Akihiro Kishimura, Yasutaka Anraku, Sayan Chuanoi, Kazunori Kataoka, Monodispersed polymeric nanocapsules
spontaneous evolution and morphology transition from reducible hetero-PEG PICmicelles by controlled degradation, Journal of the American Chemical Society, 10.1021/ja808419b, 131, 11, 3804-3805, 2009.03, 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)]..
78. Akihiro Kishimura, Sittipong Liamsuwan, Hiroyuki Matsuda, Wen Fei Dong, Kensuke Osada, Yuichi Yamasaki, Kazunori Kataoka, PH-dependent permeability change and reversible structural transition of PEGylated polyion complex vesicles (PICsomes) in aqueous media, Soft Matter, 10.1039/b815884c, 5, 3, 529-532, 2009, 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..
79. Hidehiro Oana, Akihiro Kishimura, Yuichi Yamasaki, Masao Washizu, Kazunori Kataoka, Spontaneous formation of giant unilamellar vesicles from microdroplets of a polyion complex by focused infrared laser irradiation, 20th Anniversary MHS 2009 and Micro-Nano Global COE - 2009 International Symposium on Micro-NanoMechatronics and Human Science 20th Anniversary MHS 2009 and Micro-Nano Global COE - 2009 International Symposium on Micro-NanoMechatronics and Human Science, 10.1109/MHS.2009.5352051, 155-160, 2009, 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..
80. H. Oana, K. Yonehara, Akihiro Kishimura, Y. Yamasaki, K. Kataoka, M. Washizu, Spontaneous formation of polymer vesicles from microdroplets of polyion complex via microphase separation, 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2008 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference, 631-633, 2008, 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..
81. Yuan Li, Woo Dong Jang, Nobuhiro Nishiyama, Akihiro Kishimura, Satoko Kawauchi, Yuji Morimoto, Sayaka Miake, Takashi Yamashita, Makoto Kikuchi, Takuzo Aida, Kazunori Kataoka, Dendrimer generation effects on photodynamic efficacy of dendrimer porphyrins and dendrimer-loaded supramolecular nanocarriers, Chemistry of Materials, 10.1021/cm071451m, 19, 23, 5557-5562, 2007.11, 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-b-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 G1 and G2, their fluorescence lifetime and oxygen consumption ability were significantly reduced by the formation of the PIC nanocarriers, whereas the G3-loaded 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..
82. Akihiro Kishimura, Aya Koide, Kensuke Osada, Yuichi Yamasaki, Kazunori Kataoka, Encapsulation of myoglobin in PEGylated polyion complex vesicles made from a pair of oppositely charged block ionomers
A physiologically available oxygen carrier, Angewandte Chemie - International Edition, 10.1002/anie.200701776, 46, 32, 6085-6088, 2007.08, (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..
83. Aya Koide, Akihiro Kishimura, Kensuke Osada, Woo Dong Jang, Yuichi Yamasaki, Kazunori Kataoka, Semipermeable polymer vesicle (PICsome) self-assembled in aqueous medium from a pair of oppositely charged block copolymers
Physiologically stable micro-/nanocontainers of water-soluble macromolecules, Journal of the American Chemical Society, 10.1021/ja057993r, 128, 18, 5988-5989, 2006.05, A new entity of polymer vesicle with a polyion complex (PIC) membrane, a PICsome, was prepared by simple mixing of a pair of oppositely charged block copolymers, composed of biocompatible PEG and poly(amino acid)s, in an aqueous medium. Flow particle image analysis revealed the formation of spherical particles with a size range up to 10 μm. Observation by dark-field and confocal laser scanning microscopes clearly confirmed that the PICsome has a hollow structure with an inner-water phase, in which FITC-dextran emitting green fluorescence was successfully encapsulated simply by the simultaneous mixing with the block copolymers. Confocal laser scanning microscopic observation and spectral analysis revealed the smooth penetration of a low molecular weight fluorescent dye (TRITC; MW = 443.5) emitting red fluorescence into the FITC-dextran encapsulated PICsome to give the PICsome image with a merged color of yellows, indicating the semipermeable nature of the PICsome membrane. The PICsomes showed appreciable physiological stability even in the presence of serum proteins, suggesting their feasibility in biomedical fields such as carriers of therapeutic compounds and compartments for diagnostic enzymes..
84. Tomovuki Kishi, Joon Sik Park, Akihiro Kishimura, Kazunori Kataoka, Synthesis of poly(2-oxazoline)s block copolymers with different functional groups at both terminal and the evaluation of their thermo-sensitive behaviors, 55th Society of Polymer Science Japan Symposium on Macromolecules 55th SPSJ Symposium on Macromolecules, 55, 5048-5049, 2006, 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..
85. Tomovuki Kishi, Joon Sik Park, Akihiro Kishimura, Yuichi Yamasaki, Kazunori Kataoka, Synthesis of the thermosensitive poly (oxazolines) and formation of the aggregates, 55th SPSJ Annual Meeting Polymer Preprints, Japan - 55th SPSJ Annual Meeting, 55, 567, 2006, 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..
86. Akihiro Kishimura, Takashi Yamashita, Takuzo Aida, Phosphorescent organogels via "metallophilic" interactions for reversible RGB-color switching, Journal of the American Chemical Society, 10.1021/ja0441007, 127, 1, 179-183, 2005.01, A trinuclear Au(I) pyrazolate complex bearing long alkyl chains (1) in hexane self-assembles via a Au(I)-Au(I) metallophilic interaction, to form a red-luminescent organogel (λem = 640 nm, λ 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 (λem = 458 nm, λext = 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 (λem = 501 nm, λext = 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 μs) and assigned to electronic transitions from triplet-excited states..
87. Akihiro Kishimura, Takashi Yamashita, Kentaro Yamaguchi, Takuzo Aida, Rewritable phosphorescent paper by the control of competing kinetic and thermodynamic self-assembling events, Nature Materials, 10.1038/nmat1401, 4, 7, 546-549, 2005.01, The development of a novel photoluminescent ink for rewritable media that dichroically emits phosphorescence due to a structural bistability of the self-assembled luminophor is discussed. By coating a white polyethylene terephthalate (PET) paper with a Cu(I) complex containing a polymer support were fabricated. The photoluminescent ink is used for rewritable media that dichroically emits phosphorescence due to a structural bistability of the self-assembled luminophor. This feature is realized by the control of kinetic and thermodynamic processes that can provide security technology for information handling..
88. Akihiro Kishimura, Aya Koide, Joon Sik Park, Kensuke Osada, Yuichi Yamasaki, Kazunori Kataoka, The design of "PICsome" in aqueous medium based on oppositely charged block copolymers, 54th SPSJ Symposium on Macromolecules 54th SPSJ Symposium on Macromolecules - Polymer Preprints, Japan, 54, 3529, 2005, 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..
89. M. Enomoto, Akihiro Kishimura, T. Aida, Coordination metallacycles of an achiral dendron self-assemble via metal-metal interaction to form luminescent superhelical fibers [17], Journal of the American Chemical Society, 10.1021/ja010426t, 123, 23, 5608-5609, 2001.10.