▎ 摘　　要

Basedon the excellent photothermal conversion performance of grapheneoxide (GO) and the shrinkage of thermoresponsive copolymer chain segments,a GO-polymer hybrid hydrogel carrier system was designed toload stem cell exosomes that have repair and nutritional functionson nerve cells and play a synergistic role in the proliferation andmigration of Schwann cells (SCs). The surface modification of hydroxypropylchitosan on GO was carried out based on the EDC reaction, and GO-hydroxypropylchitosan (GC) with well hydrophilicity and dispersion was obtained.The thermoresponsive copolymer poly(2-hydroxyethyl methacrylate-co-2-(2-methoxyethoxy) ethylmethacrylate-co-oligo(ethylene glycol) monomethyl ether methacrylate) (P(HEMA-co-OEGMA-co-MEO(2)MA), PHOM) wasprepared by atom transfer radical polymerization. After aldehyde modification,PHOM-CHO was cross-linked with GC through a dynamic Schiffbase bond to form a thermoresponsive hydrogel. Due to the near-infrared(NIR) photothermal conversion of GO and the thermoresponsive contractionof the hydrogel network, the hydrogel can achieve controlled releaseof the loaded exosomes. Cell experiments showed that the GO-thermoresponsivepolymer hybrid hydrogel had good biocompatibility. Further tests onthe promoting effect of the exosome-loaded hydrogel on Schwann cells(SCs) showed that the exosomes could be released in a controlled waythrough NIR irradiation, and the synergistic effect of exosomes andthe GO hybrid hydrogel promoted the proliferation and migration ofSCs.