抄録
As a powerful cell manipulation alternative in the recent rapid progress of cell biology, we are introducing a novel method which enables selective killing or detachment of the adherently cultured cells by micropattern projection onto a photo–responsive culture substrate functionalized with photo–acid–generating (PAG) polymers. We synthesized PAG polymers, which generate strong acid in response to visible light irradiation, and fabricated photo–responsive cell culture substrates by forming a thin layer of the PAG polymer on a polystyrene culture surface. Several anchorage dependent cell lines including CHO–K1, NIH/3T3, MDCK, HeLa and HepG2 were cultured on this surface until confluent, and test patterns were projected onto the substrates with the blue light using a PC–controlled micro–pattern irradiation system. A few minutes after irradiation, cell viability was examined by checking esterase activity and membrane permeability to find that all cells in the irradiated area were effectively killed, leaving neighboring cells perfectly intact. Further, we fabricated another type of culture substrate by introducing the PAG polymer and copolymer containing 4–vinylpyridine on the culture surface of a polystyrene dish in order to implement photo–induced cell detachment. NIH/3T3 cells were cultured on this surface until confluent, and the blue light was irradiated locally within a circular area of 5 mm diameter for a few minutes. In a few hours after irradiation, we observed that most of the cells became detached from the irradiated area while no detectable change was found for the cells outside of the area. We collected the detached cells, and examined their viability by checking membrane permeability. As a result, about 85 % of the cells were estimated to maintain their viability even after photo-induced detachment. Also the detachment of HepG2 adherently cultured on the culture substrate was induced by the light irradiation.
