Laser-enzyme dual responsive liposomes to regulate autophagy in synergy with phototherapy for melanoma treatment.

Phototherapy can cause autophagy while killing tumour cells, leading to tumour recurrence and metastasis. Here, we constructed a laser and enzyme dual responsive nanodrug delivery system Tf-Te@CTSL-HCQ (TT@CH) to precisely regulate autophagy in synergy with phototherapy to inhibit the proliferation and metastasis of melanoma. Firstly, transferrin (Tf) was used as a nanoreactor to synthesise phototherapy agent Tf-Te by the biological template mineralisation method. Then, the thermosensitive liposome modified with FAP-α-responsive peptide (CAP) was used as a carrier to encapsulate autophagy inhibitor hydroxychloroquine (HCQ) and Tf-Te, to obtain an intelligent TT@CH delivery system. Once arriving at the tumour site, TT@CH can be cleaved by FAP-α overexpressed on cancer-associated fibroblasts (CAFs), and release Tf-Te and HCQ. Then Tf-Te can target melanoma cells and exert PTT/PDT anti-tumour effect. What's more, hyperpyrexia induced by PTT can further promote drugs release from TT@CH. Meanwhile, HCQ simultaneously inhibited autophagy of CAFs and melanoma cells, and down-regulated IL-6 and HMGB1 secretion, thus effectively inhibiting melanoma metastasis. Pharmacodynamic results exhibited the best anti-tumour effect of TT@CH with the highest tumour inhibition rate of 91.3%. Meanwhile, lung metastatic nodules of TT@CH treated mice reduced by 124.33 compared with that of mice in control group. Overall, TT@CH provided an effective therapy strategy for melanoma.