Creation of designed shape cell sheets that are noninvasively harvested and moved onto another surface

We developed a novel method to obtain designed shape cell sheets for tissue engineering. Shaping of cell sheets were achieved by the use of poly(N-iso propylacrylamide) (PIPAAm) and poly(N,N'-dimethylacrylamide) (PDMAAm) for t emperature-responsive cell adhesive and cell nonadhesive domains, respectiv ely. These polymers were covalently grafted onto tissue culture polystyrene (TCPS) dish surfaces by electron beam irradiation with mask patterns. At 3 7 degreesC, human aortic endothelial cells (HAECs) attached, spread, and pr oliferated to make a monolayer only on PIPAAm-grafted domains. HAECs did no t adhere on PDMAAm-grafted domains for more than 1 month even under the ser um-supplemented condition. By reducing the culture temperature below 32 deg reesC, PIPAAm changed to hydrophilic and HAEC sheets were detached from PIP AAm-grafted surfaces without any need of an enzyme such as trypsin. Cell-ce ll junctions were retained in the recovered cell sheets and easily moved to virgin TCPS dishes with the aid of hydrophilically modified polyvinylidene fluoride membranes as a supporter during the transfer. Moved cell sheets ra pidly adhered onto the dish surfaces, and the supporter was easily peeled o ff from the cell layers. HAEC sheets transferred to new dishes revealed the identical shape and size to those before transfer. This novel technique is the only way to create, harvest, and transfer designed shape cell sheets a nd would have promising applications in tissue engineering.