Application of ultra thin hydrophilic polymer layer to acceleration of cell sheet recovery from temperature-responsive culture dishes

Slow recovery of cell sheet from poly(N-isopropylacrylamide) (PIPAAm) grafted TCPS surfaces is not so practical in clinical field. To solve this problem regarding the slow recovery, based on the hypothesis that hydrophilic basal surfaces promote hydration of PIPAAm chains with ultra thin thickness, we successfully prepared PIPAAm grafted culture dishes exhibiting rapid cell and cells sheet recovery. Sequential grafting appropriate amount of PAAm and PIPAAm (PIPAAm-PAAm-TCPS) attained more rapid cell and cell sheet recovery in comparison with PIPAAm grafted onto hydrophobic TCPS. Characterization of PIPAAm-PAAm-TCPSs surfaces revealed that appropriate amount of the grafted PIPAAm and PAAm is necessary to attain such rapid recovery of cell sheet, suggesting that this difference results from different properties of the basal surfaces and different mobility of the grafted polymer chains between hydrophobic TCPS and hydrophilic PAAm. In addition it also support the hypothesis.