Injectable composite hydrogel based on carbon particles for photothermal therapy of bone tumor and bone regeneration

Surgical resection, as the most efficient treatment for bone tumor, still faces a dilemma between the complete removal of tumor tissue and the maximum reservation of healthy bone tissue. In response to this, an injectable composite hydrogel with chitosan/hyaluronic acid/β-sodium glycerophosphate as the matrix and carbon particles as the photothermal agent is developed. Owing to the temperature sensitivity, the composite hydrogel can be injected into the irregular bone defect and exhibit the sol-gel phase transition upon body temperature, facilitating the conformal therapy. The composite hydrogel can ablate the human osteosarcoma on Balb/c nude mice model with the tumor inhibition rate of 98.4% after near-infrared laser irradiation (808 nm). The assessment of bone regeneration on calvarial-defect model of Sprague-Dawley rats reveals that the composite hydrogel can promote new bone formation with the bone volume/total volume ratio of 76.2% after 8 weeks, in sharp contrast to the control group of 23.9%.