An Injectable\nPhotothermal-Fusing Hydrogel: Achieving\nTemperature-Controllable Mild Photothermal Therapy to Reverse Chemotherapy-Induced\nImmune Tolerance

Mild photothermal therapy (M-PTT) can induce immunogenic\ncell death\n(ICD) to reverse the immune tolerance caused by low-dose chemotherapy.\nHowever, it still needs convenient strategies to control temperature\nduring M-PTT. In this work, the phase change material lauric acid\n(LA, melting point 43 °C) was introduced to construct nanoparticles\nloaded with deferoxamine mesylate (DFO) and cisplatin (CDDP), which\nwere mixed into a supramolecular hydrogel formed by polyvinylpyrrolidone\n(PVP)/tannic acid (TA)/Fe<sup>3+</sup> to obtain FeTP@DLD/DLC. When\nthe temperature reached 43 °C under laser irradiation, DFO was\nreleased from melted LA and destroyed the interaction between Fe<sup>3+</sup> and TA to cut off the temperature increase, achieving a\n“photothermal fusing effect”. Meanwhile, CDDP was released\nfor low-dose chemotherapy, while the resulting immune tolerance was\nreversed by M-PTT-induced ICD. Finally, through a single administration,\nFeTP@DLD/DLC-mediated M-PTT synergized with chemotherapy achieved\na potent antitumor effect. This work provided a convenient solution\nfor the revitalization of these traditional antitumor therapies.