Effect of Strontium Peroxide and Copper-Doped Hydroxyapatite Microceramics on the Osteogenesis and Antibacterial Activity of Nanofibrous Composite Scaffolds

Engineering multifunctional scaffolds that effectively promote bone regeneration while concurrently mitigating the risk of infection remains a significant challenge in the field of bone tissue engineering. In this study, we present the fabrication of electrospun poly(lactic acid) (PLA) nanofibrous composite scaffold (PLASrCu) incorporating strontium peroxide (SrO2) and copper-doped hydroxyapatite (CuHA) particles. The resulting composite scaffold exhibited interconnected porous structures and extracellular matrix-like morphologies. Physicochemical characterization confirmed the preservation of PLA chemical structure and the successful incorporation of crystalline SrO2 and CuHA phases, with the tensile strength increasing from 2.3 to 2.8 MPa. The PLASrCu scaffold exhibited sustained ion release of Sr and Cu (12.2 and 13.3 mg/L, respectively, over 14 days), together with controlled oxygen generation (10.2 mg/L within 30 min), particularly under hypoxic conditions. In vitro biological assessments demonstrated that the PLASrCu scaffold significantly enhanced cell proliferation and viability. Moreover, osteogenic differentiation and mineralization were markedly promoted, as evidenced by upregulated expression of COL1, OPN, and RUNX2 (5.1-, 2.6-, and 1.9-fold increases, respectively) and increased calcium deposition. Importantly, the Cu-containing scaffolds effectively inhibited the growth of Staphylococcus aureus and Pseudomonas aeruginosa, resulting in antibacterial rates above 99.9%. Collectively, these results demonstrate that the PLASrCu nanofibrous scaffold integrates osteogenic, oxygen-generating, and antibacterial functions within a single platform, highlighting its strong potential for the regeneration of infected and oxygen-deficient bone defects.