Osteogenic and antibacterial properties of vancomycin-laden mesoporous bioglass/PLGA composite scaffolds for bone regeneration in infected bone defects

Abstract

Chronic osteomyelitis and infected bone defects are substantial challenges faced by orthopaedic surgeons. In this study, vancomycin was loaded into mesoporous bioactive glass (MBG) to form a local antibiotic delivery system and then a bone tissue-engineering scaffold combining MBG and poly-(L-lactic-co-glycolic acid) (PLGA) was prepared by freeze-drying fabrication. In vitro degradation and water contact angle analysis suggested that the MBG-incorporated PLGA scaffold exhibited controlled degradability, stabilizing the pH of the surrounding environment and improved the hydrophilicity. Moreover, the presence of MBG provides a well-interconnected pore structure, to which human bone marrow-derived mesenchymal stem cells can attach, spread and proliferate, promoting upregulation of the expression of osteogenic markers. Thus, MBG/PLGA scaffolds exhibit better cytocompatibility and osteoblastic difierentiation properties compared with pure PLGA scaffolds. Vancomycin-loaded scaffolds have been found to yield sustained release that lasts for more than eight weeks in vitro. We tested the antibacterial performance of vancomycin-loaded scaffolds against Staphylococcus aureus, the most common bacteria isolated from infected bone. In vitro experiments demonstrated that loading vancomycin onto the scaffold promoted antibacterial activity and inhibited biofilm formation without deleterious effect on cytocompatibility. In conclusion, the novel inorganic-organic composites are considered potential materials for the treatment of infected bone defects.