Effective\nAntitumor Synergistic Treatment with Fiber-Photothermal\nTherapy and Heat Shock Protein Inhibitors

Effective\ntreatment of malignant tumors remains a thorny issue\nin current medicine. As a new type of anticancer strategy, photothermal\ntherapy (PTT) has attracted tremendous attention due to its favorable\ntherapeutic effectiveness, high spatial-temporal controllability,\nand low occurrence of side effects. However, the efficacy of PTT is\nsignificantly reduced due to the limited penetration of light and\nheat-induced overexpression of heat shock protein (Hsp). Herein, we\npropose an antitumor synergistic therapy that combines fiber-optic\nPTT and Hsp inhibitors. A rare-earth-doped optical fiber was used\nas the PTT actuator, and the Hsp inhibitor AT533 was loaded on the\nfiber surface by use of a hydrogel layer. PTT fibers can be guided\nto reach tumor lesions directly without being subject to the light\npenetration limit. The Hsp inhibitor can be released upon the softening\nof the hydrogel layer under photoheating to deactivate Hsp in the\ntumor and thus reduce the resistance of the tumor to PTT. This synergistic\ntreatment enhanced the effect of PTT and successfully eradicated tumors\nin colorectal cancer (CRC) xenograft mouse models, providing a feasible\nway to realize antitumor and antirecurrence treatment. More importantly,\nthe success of the synergistic treatment of PTT and Hsp inhibition\nopens new avenues for the development of multimodal and multitype\nsynergistic fiber-optic treatments, which offer pronounced enhancement\nof therapeutic effectiveness for treating cancer.