Chitosan Thermosensitive Hydrogel Based on DNA Damage Repair Inhibition and Mild Photothermal Therapy for Enhanced Antitumor Treatment.

The DNA damage repair of tumor cells limits the effect of photothermal therapy (PTT), and high temperatures induced by PTT can damage adjacent normal tissues. To overcome these limitations, we developed a novel composite hydrogel (OLA-Au-Gel) based on chitosan (CS) and β-glycerophosphate (β-GP), which encapsulated olaparib-liposomes (OLA-lips) and CS-capped gold nanoparticles (CS-AuNPs). OLA-Au-Gel achieved the combination of mild PTT (mPTT) by CS-AuNPs and tumor DNA damage repair inhibition by OLA. The hydrogel showed good biocompatibility, injectability, and photothermal response. Under near-infrared laser irradiation, OLA-Au-Gel inhibited the proliferation of tumor cells, induced the generation of reactive oxygen species in vitro, and effectively inhibited the growth of breast tumors in vivo. OLA-Au-Gel shows a promising application prospect for inhibiting tumor development and improving the antitumor effect. Collectively, we propose a novel strategy for enhanced antitumor therapy based on the combination of mPTT and DNA damage repair inhibition.