This study focuses on a copolymer of hyperbranched polystyrene and poly(N-isopropylacrylamide) (HBPSt-g-PNIPAM) as a surface modifier for conventional polystyrene (PSt) dishes to fabricate a thermo-responsive cell culture substrate, and especially discuss the role of the hyperbranched structure on the cell sheet detachment performance. HBPSt-g-PNIPAM was synthesized by grafting PNIPAM from the termini of HBPSt, and cast onto a commercial PSt-dish. Mouse 3T3 fibroblast cells cultivated on the prepared dish were successfully collected as a sheet form after cooling down the dish to 20 degrees C; however, its linear analogue did not detach cell sheets under the same condition. To highlight the effect of the hyperbranched structure, Langmuir-Blodgett (LB) films of the copolymers were studied. The LB film accumulation experiments suggest that the hyperbranched structure contributes to the exposure of the PSt segment, which probably enhance the immobilization of the PSt segment onto the PSt-dish. (C) 2016 Elsevier Ltd. All rights reserved.