Reparative Effects of 3D-Printed PLGA/CHA/nmZnO Composite Scaffolds on Inflammatory Periodontal Bone Defects in Rats

In this study, PLGA/CHA/nmZnO antibacterial bone repair scaffolds with different contents of CHA/nmZnO (0%, 15%, 25%, 30%, 35%) were prepared by 3D melt extrusion molding technology. The physicochemical properties, biocompatibility, and in vitro osteogenic performance of the scaffolds were characterized, and a rat model of periodontitis bone defect was constructed to evaluate the osteogenic effect of the scaffolds. Results showed that the scaffolds exhibited interconnected pore structures and appropriate mechanical properties. The contact angles were measured to be between 73.37° ± 1.36° and 85.03° ± 1.45°. The composite scaffolds of the 25%, 30%, and 35% groups had a significant promoting effect on the proliferation and osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs). In the bone defect model, the 30% scaffold showed substantial osteogenic effects at 6 weeks post-implantation, characterized by significant increases in BV/TV, BS/TV, and area of collagen formation, along with decreased trabecular separation. At 12 weeks, the volume fraction and collagen area of new bone surpassed those of Bio-Oss bone graft. Immunohistochemistry indicated that this scaffold effectively inhibited expression of inflammation-related factors TLR2, TLR7, and IL-1β. This study systematically compared the effects of CHA/nmZnO filler content on the performance of PLGA scaffolds, and selected 30% as the optimal ratio, which has both osteogenic induction and immune regulation functions, providing a new design idea for the development of periodontal bone regeneration materials.