Mussel-inspired in situ fabrication of a photothermal composite hydrogel for MR-guided localized tumor ablation

Photothermal ablation could be considered an effective treatment for tumors, but accurate administration and enrichment of photothermal agents remain a huge challenge. Herein, a mussel-inspired photothermal polymeric hydrogel (PPH) was synthesized through a ferric iron-triggered simultaneous metal-catechol coordination reaction and oxidative polymerization of covalently linked pyrrole. The PPH with rapid gelation (less than 10 s) exhibited high photothermal conversion efficiency (49.3%), which enabled effective hyperthermal therapy in situ. Besides, the introduced iron could be used as a T-2-weighted contrast agent for real-time MR imaging to explore the retention and bio-degradation of PPH in vivo. Overall, our findings evidence that the resultant PPH, which possesses potential application in tumor ablation in situ, and metal-catechol coordination strategy inspired by mussel adhesion may stimulate biomedical hydrogel development.