Sacrificial film-assisted transfer of in vitro-cultivated epithelial cell sheets from thermoresponsive surfaces: a preliminary study towards enhancing ease of handling in cell sheet engineering

Aim: Cell sheet technology is a transformative approach in epithelial tissue engineering, offering scaffold-free constructs that preserve cell-cell and cell-matrix interactions, enabling better integration with host tissues. However, safe and efficient transfer of these fragile sheets remains a critical challenge, limiting their broader clinical adoption. This study aims to develop a facile method for the retrieval and transfer of epithelial cell sheets cultivated over thermo-responsive polymer surfaces (TRPS) using sacrificial films. Methods: Three epithelial cell lines, HCE-S (cornea), HaCaT (skin), and A549 (lung), were cultured on poly(N-isopropylacrylamide-co-glycidyl methacrylate) (P(NIPA-GMA)) coated TRPS and conventional tissue culture surfaces. Upon reaching confluence, the dishes were incubated below the lower critical solution temperature to induce phase transition in TRPS. Subsequently, sacrificial films made of polyethylene oxide, gelatin and their blend were used to lift and transfer the cell sheets to new culture dishes containing a minimal amount of culture medium. Additional medium was then added to dissolve the film, allowing the cell sheet to settle gently onto the dish surface. Results: In all three epithelial cell types, a continuous, confluent cell sheet was visible on the TRPS prior to transfer. Subsequent to temperature lowering and sacrificial film assisted transfer, the master TRPS dish exhibited a distinct void corresponding to the sheet removal, confirming successful detachment. The transferred sheets reattached successfully and maintained over a one-week observation period. Conclusions: The sacrificial film-based transfer method provided a gentle, efficient and scalable alternative for handling cell sheets from TRPS. This approach enhances the translational potential of cell sheet engineering and supports its integration into clinical workflows for epithelial tissue regeneration.