Electrospun polycaprolactone-chitosan nanofibers on a zinc mesh as biodegradable guided bone-regeneration membranes with enhanced mechanical, antibacterial, and osteogenic properties for alveolar bone-repair applications

Guided bone-regeneration membrane (GBRM) is commonly used in bone-repair surgery because it blocks fibroblast proliferation and provides spatial support in bone-defect spaces. However, the need for removal surgery and the lack of antibacterial properties of conventional GBRM limit its therapeutic applicability for alveolar bone defects. Here we developed a GBRM for alveolar bone-repair and -regeneration applications through double-sided electrospinning of polycaprolactone and chitosan layers on a Zn mesh surface (denoted DSZM). The DSZM showed a UTS of ∼25.6 MPa, elongation of ∼16.1%, strength-elongation product of ∼0.413 GPa%, and ultrahigh spatial maintenance ability, and the UTS was over 6 times higher than that of commercial Bio-Gide membrane. The DSZM exhibited a corrosion rate of ∼17 µm/y and a Zn ion concentration of ∼0.23 μg/ml after 1 month of immersion in Hanks' solution. The DSZM showed direct and indirect cytocompatibility with exceptional osteogenic differentiation and calcium deposition toward MC3T3-E1 cells. Further, the DSZM showed strongly sustained antibacterial activity against S. aureus and osteogenesis in a rat critical-sized maxillary defect model. Overall, the DSZM fits the requirements for alveolar bone-repair and -regeneration applications as a biodegradable GBRM material due to its spatial support, suitable degradability, cytocompatibility, and antibacterial and osteogenic capabilities. STATEMENT OF SIGNIFICANCE: This work reports the mechanical properties, antibacterial ability and osteogenic properties of electrospun PCL-CS nanofiber on Zn mesh as biodegradable guided bone-regeneration membrane for alveolar bone-repair applications. Our findings demonstrate that the DSZM prepared by double-sided electrospinning of PCL-CS layers on Zn mesh showed a UTS of ∼25.6 MPa, elongation of ∼16.1%, strength-elongation product of ∼0.413 GPa%, and ultrahigh spatial maintenance ability, and the UTS was over 6 times greater than that of commercial Bio-Gide® membrane. The DSZM showed direct and indirect cytocompatibility with exceptional osteogenic differentiation and calcium deposition toward MC3T3-E1 cells. Further, the DSZM showed strongly sustained antibacterial activity against S. aureus and osteogenesis in a rat critical-sized maxillary defect model.