In situ synthesized Van-ZIF-8 functionalized electrospun PCL membrane with pH-responsive dual functionality for oral guided bone regeneration

Guided bone regeneration (GBR) is a critical regenerative strategy for repairing periodontal tissues and craniofacial bone defects. It can establish space to prevent undesirable soft tissue invasion and improve bone regeneration. However, commercially available GBR membranes have some disadvantages in terms of biocompatibility and antibacterial efficacy. Hence, we prepared a polycaprolactone (PCL) membrane by electrospinning and then in situ synthesized vancomycin-assisted zeolitic imidazolate framework-8 (Van-ZIF-8) nanoparticles on its surface. With the formation of Van-ZIF-8, the mechanical properties of the PCL membrane were significantly enhanced. Moreover, the release rates of Van and zinc ions (Zn²⁺) showed pH responsiveness. In an acidic environment (pH 5.4), the fast hydrolysis of Van-ZIF-8 led to the rapid release of Van and Zn²⁺. The PCL/Van-ZIF-8 membrane exhibited enhanced antibacterial activity against both aerobic and anaerobic bacteria, including Staphylococcus aureus, Escherichia coli, Porphyromonas gingivalis, and Streptococcus mutans, through the hydrolysis of Van-ZIF-8 nanoparticles. Furthermore, the in vitro results for MC3T3-E1 and L929 cells, including cell viability, alkaline phosphatase activity, mineralization level, collagen secretion, gene expression, and fluorescence staining, demonstrated that the PCL/Van-ZIF-8 membrane possessed excellent osteoinductive capacity and could act as an ideal physical barrier to fibroblast growth.