RADIOISOTOPES

Our research group has attempted to introduce a micropattern on the surface of thermo-responsive cell culture membranes in order to improve the affinity between cultured cells and body tissues and control the direction three-dimensionally. Therefore, Poly(N-isopropylacrylamide) (PNIPAAm) was partially grafted to Ethylene-tetrafluoroethylene copolymer (ETFE) by electron beam graft polymerization method under N₂ gas atmosphere at room temperature, using a Si-made mask that is microfabricated with µm order grid shapes. Roundish micro level unevenness of approximately 3 µm, which is due to electron beam diffusion and graft chain elongation, could be observed on the surface by evaluation using a confocal laser microscope. Distribution of PNIPAAm corresponding to the uneven shape was confirmed by microscopic FT-IR. Moreover, wettability change due to temperature change was observed from evaluation of water contact angles around the lower critical solution temperature. From these result, controllability of cell attachment / detachment properties was suggested.