[Preparation and

Objective: To investigate the effects of tannic acid (TA) doping on the physicochemical properties, biocompatibility, Methods: TA was incorporated into Brushite bone cement at concentrations of 0, 1.0, 3.0, 5.0, and 10.0 mg/g of solid powder, designated as Brushite, Brushite/TA-1, Brushite/TA-2, Brushite/TA-3, and Brushite/TA-4, respectively. The compressive strength and microstructure of each group were evaluated. The extracts of the bone cements were prepared and co-cultured with MC3T3-E1 cells. Cell proliferation was assessed using the cell counting kit 8 (CCK-8) assay. The cytotoxicity was observed by Calcein/propidium iodide live/dead cell staining. Cell adhesion was observed via scanning electron microscopy. After osteogenic induction, alkaline phosphatase (ALP) activity was measured and ALP staining was performed. The expression levels of osteogenic-related genes, including runt-related transcription factor 2 (Runx2), osteocalcin (OCN), osteopontin (OPN), collagen type Ⅰ (Col-Ⅰ), and integrin-binding sialoprotein (IBSP), were detected by real-time fluorescent quantitative PCR (qRT-PCR). The antibacterial activity of the bone cement against Results: Compared with the Brushite group, the Brushite/TA-3 and Brushite/TA-4 groups exhibited significantly increased compressive strength ( Conclusion: Doping with an appropriate concentration of TA (3.0-5.0 mg/g) improves the mechanical properties, cytocompatibility, and osteogenic activity of Brushite bone cement. A higher concentration (10.0 mg/g) confers antibacterial properties but may partially inhibit cell proliferation. TA-doped Brushite bone cement demonstrates good application potential in the field of bone defect repair.