Chitosan based photothermal scaffold fighting against bone tumor-related complications: Recurrence, infection, and defects

After bone tumor resection, the severe complications including cancer recurrence, infection and extensive bone loss are still a challenge. To address this problem, a chitosan/hydroxypropyltrimethyl ammonium chloride chitosan/hydroxyapatite/black phosphorus (CS/HC/HA/BP) hybrid photothermal scaffold with a multistage photothermal strategy was developed. HC-stabilized BP endowed the scaffold with simultaneous antitumor/antibacterial properties under photothermal stimulation of <50 °C. Subsequently, excellent osteogenesis could be achieved with mild hyperthermia stimulation (∼42 °C) through up-regulating the expressions of heat shock proteins. Under NIR irradiation, the scaffold could eliminate 95 % of osteosarcoma cells as well as 97 % of E. coli and 92 % of S. aureus. The osteogenic gene expressions of ALP, COL 1A1, and OCN in photothermal group were 1.64, 1.31 and 1.27 folds higher than that of non-photothermal group in vivo, respectively. Therefore, the obtained scaffold synergized with multistage photothermal strategy was effective and a reference for the treatment of other complex diseases.