Cell adhesion control by photoinduced LCST shift of PNIPAAm-based brush scaffolds.

Poly(N-isopropylacrylamide) (PNIPAAm)-brush substrates are one of the most successful dynamic scaffolds for thermally controlling cell adhesion. Endowing substrates with photocontrollability promises further development and applications in the biomedical and bioengineering fields. In this study, we developed photoresponsive PNIPAAm copolymers by incorporation of spiropyran into the polymer chain, enabling the photoinduced shift of the lower critical solution temperatures. Their brush substrates were fabricated in a simple, facile grafting-to manner. Co-grafting with non-cell-adhesive poly(ethylene glycol) enhanced the modulation of surface chemical properties upon photostimulation; it enabled significant photocontrol of cell adhesion of several types with keeping culture temperature constant.