Reserch Project

Perfusion culture is a method of culturing cells and/or tissues by perfusing culture medium in vitro. Once tissues or organs are taken out from a living body, they need to be supplied with nutrition and oxygen artificially because of the lack of blood perfusion. We have tried to research “Extra- Corporeal Organ Regeneration” utilizing this perfusion culture method to solve the problems of transplant medical care such as shortage of donors. Moreover, perfusion culture would be also beneficial to fabrication of tissues or organs in vitro. We thus have aimed at contribution to develop technologies for tissue engineering and regenerative medicine.

　 We have developed "Inkjet Drying Method" as unique technology for uniform particle manufacturing. We focused on the features of inkjet printer: eject uniform-sized droplets, eject infinitesimal amount of ink droplets and perform non-contact printing. Additionally, the drying process in the atmosphere enables us to easily manufacture dried microparticles by using this system. This method has various advantages: preparation of microparticles including heat-sensitive chemicals with high concentration, facile control of particle size and narrow dispersity of particle diameter. Therefore, we succeeded in preparing various uniform microparticles with biomaterials. Currently, we have challenged to develop "Artificial oxygen carrier" and "microparticles of oxygen sensors".

　 To reconstruct 3D tissues with micro- and complicated structure in vitro, we have conducted research about bioassembling technology. Assembling bio-parts, which are tiny building units for fabrication of tissues, would enable us to prepare complex 3D tissues or organs. We especially have focused on cell fibers, one of bio-parts in the shape of strings made from cells, and tried to apply cell fiber technology to tissue engineering and regenerative medicine. In our laboratory, we fabricate various types of cell fiber with several different methods. And we believe that combination of these bio-parts will allow us to prepare tissues in which cell orientation would be highly controlled.

　 Currently, the development of regenerative medicine allow us to fabricate tissues and organs using cells and/or biomaterials. However, there is a big issue that the effective methods for long-term preservation of tissues have not been established. To solve this problem, we have focused on the cytotoxicity caused by ice crystal during cryopreserving process. Thus, we have tried to visualize the freezing phenomena using high speed video camera. The observation of the ice crystal formation inside and outside of cells would help us to elucidate the mechanism of cytotoxicity in freezing process. We expect that our finding may lead to development of new cryoprotective agents and novel freezing-thawing method. In the future, we aim to establish a cryopreservation method for tissues and organs.