ABMES

Innovations in cell-sheet engineering increasingly rely on temperature-responsive cell-culture surfaces (TRCS) to fabricate intact cell sheets for regenerative medicine and tissue engineering. However, conventional plastic-based TRCS are single-use and prone to deformation during autoclave sterilization, highlighting the need for reusable, thermally stable alternatives. In this study, poly(N-isopropylacrylamide) (PIPAAm) was grafted onto a Ti–6Al–4V alloy (PIPAAm-Ti) surface via methacryloyl units using electron beam (EB) irradiation to develop a reusable TRCS. The resulting PIPAAm layer exhibited nanoscale thicknesses ranging from 7.6 ± 0.7 nm to 22.9 ± 1.8 nm, depending on the initial monomer concentration. The surface wettability of PIPAAm-Ti was responsive to temperature changes resulting from the temperature-dependent hydration and dehydration of the grafted PIPAAm chains. Among the tested samples, PIPAAm-Ti prepared with a 50 wt% monomer concentration (50PIPAAm-Ti) had an optimal polymeric layer thickness (11.5 ± 1.1 nm) and exhibited superior temperature-dependent C2C12 cell attachment and detachment. After reaching confluence, cells were detached from 50PIPAAm-Ti as intact cell sheets simply by lowering the temperature. Temperature-dependent transmittance profiles of PIPAAm solutions subjected to autoclaving confirmed the chemical stability of the PIPAAm chains, which retained their hydration–dehydration behavior even after multiple autoclave treatments. The grafted PIPAAm layer on 50PIPAAm-Ti remained intact after repeated sterilizations. Unlike commercially available TRCSs (UpCell®), which deform under autoclave conditions, 50PIPAAm-Ti retained its functionality and supported cell-sheet fabrication for up to three reuse cycles. This reusable TRCS thus provides an environmentally friendly alternative, reducing single-use plastic waste in cell-culture applications.