Modification of polystyrene cell-culture-dish surfaces by consecutive grafting of poly(acrylamide)/poly(N-isopropylacrylamide) via reversible addition-fragmentation chain transfer-mediated polymerization

Abstract Reversible addition-fragmentation chain transfer (RAFT)-mediated and radiation-induced grafting of poly(acrylamide) (PAAm) from polystyrene (PS) cell-culture Petri dishes and subsequent chain extension of the grafts by poly(N-isopropylacrylamide) (PNIPAAm) have been achieved by pre-irradiation of PS by electron beam. Utilizing RAFT polymerization during the construction of both blocks enables the control of chain length of PAAm and PNIPAAm segments hence the thickness of both hydrophilic and hydrophobic layers within 100 nm which is crucial for the cell sheet attachment-detachment process. Characterization of the synthesized copolymers by XPS and ATR-FTIR spectroscopies, elemental and thermogravimetric analyses and ellipsometry measurements revealed grafting of double polymeric layer from PS dish surfaces. The grafted Petri dish specimens were found to be noncytotoxic. Water contact angle measurements demonstrated that dishes modified by PAAm-block-PNIPAAm brushes showed significant temperature-dependent interfacial properties in aqueous media.