The H₂O₂ Self-Sufficient 3D Printed β-TCP Scaffolds with Synergistic Anti-Tumor Effect and Reinforced Osseointegration

Tumor recurrence and massive bone defects are two critical challenges for postoperative treatment of oral and maxillofacial tumor, posing serious threats to the health of patients. Herein, in order to eliminate residual tumor cells and promote osteogenesis simultaneously, the hydrogen peroxide (H₂O₂) self-sufficient TCP-PDA-CaO₂-CeO₂ (TPCC) scaffolds are designed by preparing CaO₂ or/and CeO₂ nanoparticles (NPs)/chitosan solution and modifying the NPs into polydopamine (PDA)-modified 3D printed TCP scaffolds by rotary coating method. CaO₂ NPs loaded on the scaffolds can release Ca²⁺ and sufficient H₂O₂ in the acidic tumor microenvironment (TME). The generated H₂O₂ can further produce hydroxyl radicals (·OH) under catalysis effect by peroxidase (POD) activity of CeO₂ NPs, in which the photothermal effect of the PDA coating enhances its POD catalytic effect. Overall, NPs loaded on the scaffold chemically achieve a cascade reaction of H₂O₂ self-sufficiency and ·OH production, while functionally achieving synergistic effects on anti-tumor and bone promotion. In vitro and in vivo studies show that the scaffolds exhibit effective osteo-inductivity, induced osteoblast differentiation and promote osseointegration. Therefore, the multifunctional composite scaffolds not only validate the concept of chemo-dynamic therapy (CDT) cascade therapy, but also provide a promising clinical strategy for postoperative treatment of oral and maxillofacial tumor.