K. MATSUMURA Laboratory
<Major Research Areas>Biomaterials, Polymer Science

Functional polymeric biomaterials for controlling the functions of living systems

Research activity

　　The creation of functional polymers is a widely studied process for application in biomaterials and tissue engineering materials. Functional polymers have many applications with regard to biomaterials, such as hydrogels, bioabsorbable materials, and artificial bones. In this regard, not only bulky soft materials but also colloids, micelles, and even solutions can be studied as materials for controlling the functions of cells or tissues.

　　Polyampholytes are polymers that have both positive and negative ions in 1 molecule. Our results revealed that several kinds of polyampholytes have a cryoprotective effect on cells in solution. This interesting phenomenon is a characteristic of polymers with high electron charge, especially polyampholytes. From the cryobiological viewpoint, cells are killed because of damage caused by intracellular crystallization of water during freezing. Therefore, we usually add some membrane-permeable chemicals such as dimethyl sulfoxide to cryopreserve cells. However, the phenomenon that non-membrane-penetrating polymers such as polyampholytes can reduce the damage that occurs during freezing cannot be explained on the basis of current knowledge in cryobiology. We will investigate and develop membrane-protective materials that can control cell functions by clarifying the mechanisms underlying such effects. Polyampholytes can change their conformation by controlling the polyion complex and thus exhibit various interesting physicochemical properties. We will try to develop novel functional materials by investigating the interactions between living systems and these polymers and by using the physicochemical properties of the polymers.

　　We also perform basic and applied research on materials well-matched to living systems; this research is aimed toward the regeneration of functions in tissue engineering. In particular, we are trying to develop a novel cell culture scaffold and articular cartilage by using hydrogels with high mechanical properties. The research performed in our laboratory is aimed toward the fusion of chemistry and biology through polymer chemistry and toward the development of materials that can control living systems.

Equipment

UV-visible spectroscope, Fluorescence spectroscope, Cleanbench for cell culture, Incubator, Infrared resonance spectrometer, Differential scanning calorimeter, NMR, HPLC

The main research achievements in the past five years

1. K. Matsumura, J.Y. Bae, and S.H. Hyon, Large Scale Vitrification for the Preservation of Human induced pluripotent stem (iPS) cells using carboxylated poly-L-lysine, Low Temp. Med., in press (2011).
2. J. Nakamura, N. Nakajima, K. Matsumura, and S.H. Hyon, In vivo cancer targeting of water-soluble taxol by folic acid immobilization, J. Nanomedic. Nanotechnol., in press (2011)
3. K. Matsumura, J.Y. Bae, and S.H. Hyon, Polyampholytes as cryoprotective agents for mammalian cell cryopreservation, Cell Transplant., 19, 691-699 (2010).
4. K. Matsumura, T. Hayami, S.H. Hyon, and S. Tsutsumi,　Control of proliferation and differentiation of osteoblasts on apatite coated poly(vinyl alcohol) hydrogel as an artificial articular cartilage material,　J. Biomed. Mater. Res.A. 92A, 1225-1232 (2010).
5. K. Matsumura, and S.H. Hyon SH, Polyampholytes as low toxic efficient cryoprotective agents with antifreeze protein properties, Biomaterials, 30, 4842-4849 (2009).