Biomimetic Antibacterial Membrane Modulates the Periodontal Inflammatory Microenvironment to Accelerate Bone Regeneration

Abstract Guided tissue regeneration, which combines barrier membranes with biocompatible scaffolds, has become an important clinical strategy for the repair of soft and hard tissue defects caused by periodontitis. However, existing barrier membranes are difficult to simultaneously meet the requirements of excellent mechanical properties, high-efficiency antibacterial activity, superior osteogenic capacity, and low cost, thus easily leading to bacterial infection and delayed bone healing. In this study, a bilayer biomimetic mineralized nanocomposite barrier membrane was constructed by combining freeze-drying with solution casting. Cellulose nanofibers (CNF) and chitosan nanofibers (ChNF) were chemically modified using a TEMPO oxidation system to introduce carboxyl active sites on their molecular chains, which significantly enhanced coordination binding and mineralization regulation capabilities for amorphous calcium phosphate (ACP). Polyacrylic acid (PAA) surface modification was used to prepare ACP with high dispersion stability, effectively improving the uniform dispersion and interface bonding of the inorganic phase in polymer matrix. The introduction of ChNF not only significantly improved the tensile ductility of the membrane, but also ameliorated the excessive swelling behavior of CNF. When increasing the ratio of ChNF to 70%, the dry- and wet-state breaking strengths of the composite membrane reached 17.54 ± 2.12 MPa and 3.76 ± 1.21 MPa, respectively. The addition of ChNF endowed the membrane with excellent antibacterial activity against Staphylococcus aureus and Escherichia coli (antibacterial rates ≥ 96%). In vitro cell experiments showed that the CNF/ChNF-ACP composite membrane had excellent cytocompatibility, which significantly promoted the adhesion, proliferation, and osteogenic differentiation of MC3T3 osteoblasts. Our membrane integrates mechanical enhancement, dimensional stability, good antibacterial activity, and osteogenic promotion, providing an easy-processing, high-performance, and translatable candidate for periodontal guided tissue regeneration.