Antibacterial bone defect repair via PCL/PLGA/HA/MgO NPs composite scaffolds

Bacterial infection remains a major challenge in bone defect repair. This study presents a novel antibacterial bone tissue engineering scaffold composed of a polycaprolactone/polylactic-co-glycolic acid/hydroxyapatite (PCL/PLGA/HA) composite, incorporating magnesium oxide nanoparticles (MgO NPs). The composite scaffold was fabricated via melt blending and subsequently surface-modified with MgO NPs using a spray-coating technique. The morphology, structure, and composition of the scaffolds were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The study evaluated the mechanical properties, degradation behavior, and biocompatibility of the scaffolds. In vitro antibacterial assays demonstrated that MgO NPs conferred significant antibacterial activity. Both in vitro and in vivo osteogenic experiments revealed that the composite scaffold effectively promoted osteogenic differentiation of rabbit bone marrow mesenchymal stem cells and new bone formation. In vivo studies further showed that the MgO NPs-incorporated scaffolds significantly enhanced the repair of rabbit cranial defects and effectively inhibited infection. These results suggest that this novel PCL/PLGA/HA/MgO NPs composite scaffold exhibits excellent biocompatibility, antibacterial efficacy, and osteogenic potential, thus presenting itself as a promising biomaterial for bone defect repair. • Antibacterial Scaffold via Melt-Blend/Spray-Coat. • MgO NPs Confer Antibacterial Activity. • Promotes BMSC Osteogenesis. • Accelerated Bone Repair In Vivo (Rabbit Model). • Antibacterial Microenvironment Drives Repair.