Full Length ArticleThermo-responsive polymer brushes on glass plate prepared from a new class of amino acid-derived vinyl monomers and their applications in cell-sheet engineering

•Amino acid-based polymer brushes were prepared on glass plate by SI-ATRP.•Brushes showed phase transitions from swollen to collapsed states.•Transition temperature (TT) could be varied by adjusting the copolymer composition.•Brushes above TT behaved as effective support for cell adhesion without toxicity.•Resultant cell-sheets were detached by cooling below the corresponding TTs.

In this study, we present a novel thermo-responsive polymer platform that is based on the alanine methyl ester-containing homopolymer (PNAAMe) and the copolymer with glycine methyl ester-based vinyl monomer (P(NAAMe-co-NAGMe)) brushes prepared via surface-initiated atom transfer radical polymerization. Water contact angles for these brushes measured at different temperatures reveal that the polymer brushes collapse and dehydrate around 13 °C and 25 °C (TTs), respectively, upon elevating the temperature. At 37 °C, seeded fibroblasts (NIH/3T3) adhere to and spread well onto these brush surfaces although the copolymer brush of P(NAAMe-co-NAGMe) depresses the number of adherent cells less than half of that for the homopolymer of PNAAMe after 24 h of cell culture due to increment in hydrophilicity. To prepare the cell-sheet, the cells are seeded on both polymer brushes and cultured at 37 °C in the presence of serum. After 4 days, the cells proliferated confluently on these brush surfaces. Lowering the temperature to 4 °C and 20 °C below TT of each brush led to the cell-sheet detachment as a monolayer form from the polymer brushes accompanying with the switching of surface affinity.

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