Cell attachment and detachment on micropattern-immobilized poly(N-isopropylacrylamide) with gelatin

To investigate by microscopic observation the effects on cell behaviour of immobilized polymers, a micropattern-immobilization technique using a photo-mask was employed. Poly(acrylic acid) or poly(N-isopropylacrylamide-co-acrylic acid) was coupled with azidophenyl groups to form a photo-reactive polymer. The photo-reactive polymer was coated, with or without gelatin, on a cell-culture polystyrene plate and photo-irradiated through a micropatterned photo-mask. Mouse fibroblast STO cells were cultured on the micropattern-immobilized plate. The surface wettability of the immobilized plate was examined by measurement of the contact angle in the cell culture medium. The attachment of cells on the plate was significantly affected by the surface properties. Although the poly(acrylic acid) has the same effect on cell adhesion as a bare polystyrene surface, co-immobilization with gelatin significantly enhanced cell adhesion, while poly(N-isopropylacrylamide) reduced it. However, co-immobilization with gelatin enhanced cell adhesion, and, on the co-immobilized surface, cell detachment was observed by lowering the temperature. Micropattern immobilization was useful for comparing the effects of materials on cell behavior and for constructing biochips.