Injectable and self-healing photothermal hydrogel with pH/photothermal dual-responsive mesoporous polydopamine for...

Given the limitations of traditional melanoma treatments like surgery and chemotherapy, novel strategies are urgently needed. At present, photothermal therapy has attracted widespread attention. However, the photothermal nanoparticles employed in this therapeutic approach encounter difficulties in accumulating at tumor sites when administered systemically. Moreover, they also pose challenges in terms of systemic toxicity. To address these challenges, an injectable photothermal-responsive hydrogel has been developed, which is easy to prepare and administer. This hydrogel consists of chitosan oligosaccharides functionalized with polyisopropylacrylamide, oxidized tremella polysaccharides, and mesoporous polydopamine loaded with doxorubicin. The hydrogel forms a dual-crosslinked network structure through Schiff base reactions and intermolecular interactions, offering both injectability and self-healing properties. The mesoporous polydopamine serves as the photothermal-responsive component and a drug reservoir for doxorubicin, allowing the hydrogel to achieve effective photothermal effects and sustained drug release in response to pH changes. Additionally, the hydrogel also exhibits anti-inflammatory effects. This composite hydrogel, combining photothermal therapy and chemotherapy, shows promising antitumor activity against B16 melanoma in vivo. Overall, this work demonstrates that the hydrogel can effectively treat melanoma in vivo, providing a theoretical foundation for its application in the comprehensive treatment of melanoma.