Development of a Dual-Drug-Loaded Bone Cement with Osteogenic Potential and Antibiotic Release

To address the dual challenges of poor osteogenesis and postoperative infection in bone repair, a novel calcium sulfate-based composite bone cement coloaded with osteoinductive phytochemicals (icariin (ICA) or soybean isoflavone (SI)), and the antibiotic vancomycin (VCM) was developed. The solid phase consisted of bamboo fibers and silica-reinforced calcium sulfate. This study systematically investigated the impact of drug incorporation on the material's microstructure, setting time, mechanical strength, degradation behavior, cytocompatibility, and drug release profile. Results indicated that the drugs were physically incorporated without chemical bonding to the matrix. The setting time (postdrug loading) increased from ∼12 min (drug-free control) to 13-16 min, the compressive strength decreased from 91.4 MPa to a range of 50.4-78.7 MPa, depending on the drug loading, and the optimized formulations maintained sufficient handleability and mechanical integrity. Notably, after 8 weeks of degradation, the compressive strength remained within 26-30 MPa, matching the requirements for cortical bone defect repair. In vitro cell culture experiments demonstrated that the cell viability (OD) increased from 0.45 (drug-free control) to 0.50-0.75 in a drug content-dependent manner. Furthermore, the composite bone cement exhibited a sustained drug release profile over an extended period. Specifically, the dual drugs (0.5% SI/ICA + 2% VCM) achieved an optimal balance between handling properties, outstanding bioactivity, and sustained drug release. This multifunctional bone cement presents a promising strategy for enhancing bone regeneration while enabling localized antibiotic delivery for potential infection prevention.