Construction of a Chondrocyte Cell Sheet Using Temperature-Responsive Poly(N-isopropylacrylamide)-co-Acrylamide

In this study, a novel temperature-responsive poly(N-isopropylacrylamide)-co-acrylamide was used to prepare a chondrocyte cell sheet. Chondrocytes were isolated from human articular cartilage and plated on the copolymer film grafted tissue culture plates. The cell attachment on the copolymer film was shown to be similar to that of the ungrafted surface. To harvest a cell sheet, the incubation temperature was reduced to 10 degrees C for 30 minutes to allow the polymer chain to fully extend, changing the copolymer's phase from hydrophobicity to hydrophilicity. Additional incubation at 20 degrees C for 60 minutes was necessary to activate the cellular metabolism required for cytoskeletal organization and cell detachment. A complete cell sheet recovery was achieved when a PVDF membrane was used as a cell sheet carrier. Unfortunately, the shrinkage of the cell sheet was observed. Nonetheless, the harvested cell sheet was shown to be viable and healthy.