Magnesium + coral hydroxyapatite/tannin dual-functional composite film for suppressing bone tumors and promoting ossification.

The management of post-resection osteolytic defects and prevention of tumor recurrence caused by residual malignant cells remain critical challenges in bone tumor therapy. There is an urgent need to develop bifunctional implants capable of simultaneous bone regeneration and tumor suppression. In this study, we synergistically combine pulsed laser deposition (PLD) and low-energy electron beam deposition (EBD) technologies to achieve precise construction and functional optimization of composite structures. Through this innovative integration, we successfully fabricate a bifunctional bilayer film composed of magnesium+coral hydroxyapatite (Mg + CHA) and tannic (TA). The composite system is systematically evaluated for its osteogenic and antitumor dual functionality, as well as the synergistic release mechanisms of therapeutic ions and drugs. This work provides a novel approach for the development of multifunctional biofilm materials. Material characterization including SEM, XRD, and XPS confirm the successful fabrication and structural properties of the films. Simulated body fluids (SBF) immersion studies demonstrate sustained release kinetics of TA along with concurrent release of Ca2+ and Mg2+ ions, which collectively promote hydroxyapatite biomineralization. Both in vitro cellular experiments and in vivo animal studies are conducted to assess the tumor-inhibiting and bone-regenerating capabilities of the composite films. The results reveal that the TA component enabled long-term drug release and significantly suppressed tumor growth, while the Mg + CHA effectively enhance bone regeneration. This bifunctional system exhibite excellent dual performance, demonstrating great potential for clinical applications in bone tumor treatment and reconstruction.