Construction and characterization of antibacterial PLGA/wool keratin/ornidazole composite membranes for periodontal guided tissue regeneration

Postoperative infections caused by bacteria are now thought to be the main cause of guided tissue regeneration (GTR) failure. In this study, six groups of PLGA/wool keratin composite GTR membranes loaded with the antibacterial agent ornidazole (0% ORN, 1% ORN, 5% ORN, 10% ORN, 20% ORN, and 30% ORN composite membranes) were prepared by an electrospinning method. The surface morphology and physicochemical properties of the composite membranes were determined, and the in vitro drug release behavior, bacteriostatic properties and in vitro cytotoxicity were assessed to optimize the amount of drug loaded into the composite membranes. The composite membrane with 1% ORN showed strong water absorption and mechanical properties as well as suitable in vitro degradation and drug release characteristics; the 5% ORN composite membrane showed good water absorption and degradation characteristics; and the 10% ORN composite membrane showed good mechanical and degradation properties. The five PLGA/wool keratin/ornidazole composite membranes could release ornidazole continuously for 7 d. When the content of ornidazole in the composite membranes was greater than or equal to 10%, the growth of human periodontal ligament fibroblasts (hPDLFs) was inhibited, while composite membranes with an ornidazole content of less than 10% facilitated the growth and proliferation of hPDLFs and could promote their osteogenic differentiation. The five PLGA/wool keratin/ornidazole composite membranes all inhibited the growth of Porphyromonas gingivalis (Pg), Fusobacterium nucleatum (Fn) and Peptostreptococcus anaerobius (Pa), and higher drug contents resulted in stronger bacteriostatic effects. In summary, the 1% ORN composite membrane had good physicochemical properties, biocompatibility and bacteriostatic properties, making this membrane applicable for use as an antibacterial GTR membrane for periodontal tissue repair.