Stable preparation of transplantable periodontal ligament-derived mesenchymal stem cell sheets in thermoresponsive culture dishes with tunable cell detachability.

Tissue engineering plays a pivotal role in the advancement of regenerative medicine. Thermoresponsive culture dishes, coated with specialized polymers that control cell adhesion through temperature fluctuations, enable the processing of cells into sheets for medical applications while maintaining their intact state. Cell sheets prepared using these culture dishes have been incorporated into several commercial pharmaceutical products. However, controlling the detachability of cell sheets using conventional thermoresponsive culture dishes remains a challenge, and often leads to unexpected detachment during cultivation. In this study, we developed a thermoresponsive culture dish with tunable cell detachability using a thermoresponsive block copolymer, poly(butyl methacrylate)--poly(-isopropylacrylamide) (PBMA-PIPAAm), which is a specialized polymer that allows precise control of the amount of surface-immobilized polymer and polymer layer thickness. Culturing periodontal ligament-derived mesenchymal stem cells on these dishes demonstrated fully tunable detachability without compromising cell properties compared to conventional thermoresponsive dishes (UpCell®). Thermoresponsive PBMA-PIPAAm-coated culture dishes enable the complete on-demand detachment of transplantable cell sheets, thereby avoiding unexpected detachment that may increase production costs and reduce technical hurdles in the manufacturing process. The PBMA-PIPAAm coating method has the potential to contribute to biomedical and clinical applications of mesenchymal stem cell sheets.