|Daisuke Mizuno||Last modified date：2019.06.24|
Field of Specialization
biological physics, softmatter, biorheology
research: biological soft matter, nonequilibrium statistical mechanics of life
Research InterestsMembership in Academic Society
- nonequilibrium mechanics and fluctuation in active gels
exploring the physical calibration mechanism for cellular mechano-sensing
driven nonequilibrium mechanics in aging colloidal glass
keyword : microrehology, nanobiology, biomechanics, nonequilibrium statistical mechanics, active gel, cancer, neuron,glycoprotein
- biophysical socioety
- 2006 Bacabac, R.G., Mizuno, D., Vatsa, A., Schmidt, C., MacKintosh, F.,Van Loon, J.J.W.A., Klein-Nulend, J., Smit, T.H.(Amsterdam, The Netherlands) “Round versus flat: Bone cell morphology, elasticity and mechanosensing”
- "Nonequilibrium mechanics of active cytoskeletal networks", D. Mizuno, C. Tardin, C.F. Schmidt, F.C. MacKintosh, Science, 315, 370-373 (2007)
"High resolution probing of cellular force transmission", D. Mizuno, R.G. Bacabac, C. Tardin, D. Head, C.F. Scmidt, Phys. Rev. Lett.. 102, 168102 (2009)
- In much the same way that each of our bodies depends on bones for mechanical integrity and strength, each cell within our bodies is mechanically supported by a skeleton of stiff proteins, called the cytoskeleton. Furthermore, analogous to how our bones are held and moved by muscles, the cytoskeleton is activated by molecular motors, which are nanometer-sized force-generating enzymes. The interior of cells is driven far from equilibrium by such force-generating machinery. In order to study the physics governing such biological systems, developing a new technology to quantify the nonequilibrium property is essential. In this study, mechanical activity similar to that of living cells were investigated in a simplified model system composed of a cytoskeletal protein (actin) with a crosslinker and a motor (myosin).
In order to investigate the non-equilibrium behavior of the model system, Daisuke Mizuno had developed a novel laser-based technique for simultaneous active and passive microrheology. With this technique, the degree of nonequilibrium activity in the model system was quantified by the violation of the fluctuation-dissipation theorem. The viscoelasticity and internal stresses of such an active material were simultaneously quantified for the first time. It is found that the model cytoskeleton exhibits local contractions similar to living cells, and that these contractions stiffen the system up to 100 times in a manner that can be controlled. A quantitative nonequilibrium physical model to explain those behaviors was also presented.
These findings demonstrate that a remarkably simple system, with just three components, can reproduce key phenomena also observed in far more complex living cells. The artificial cytoskeleton designed in this study is an adaptive/active system that can tune its own mechanical properties, as with cells or tissues. This provides new fundamental insights for biological science and design principles for materials science.