Injectable charge-complementary hyaluronic acid/ϵ-Poly-L-lysine hydrogel loaded with BMP-2 for potential antibacterial and osteogenic management of peri-implantitis.

Peri-implantitis is a biofilm-associated infectious disorder marked by progressive peri-implant bone loss and remains a major cause of late implant failure. To achieve simultaneous antibacterial treatment and bone regeneration, an injectable charge-complementary hydrogel (BMP-2@HA/ϵ-PL) was fabricated using anionic hyaluronic acid (HA), cationicϵ-poly-L-lysine (ϵ-PL), and positively charged bone morphogenetic protein-2 (BMP-2). Its structural and physicochemical features were examined by Fourier-transform infrared spectroscopy, scanning electron microscopy (SEM), rheological testing, compression analysis, and swelling-degradation behavior assessments. BMP-2 release was quantified by enzyme-linked immunosorbent assay.In vitro, cytocompatibility of the BMP-2@HA/ϵ-PL hydrogel with rat bone marrow mesenchymal stem cells (BMSCs) was evaluated by CCK-8 and live/dead staining, whereas osteogenic differentiation was assessed by alkaline phosphatase activity, calcium deposition, and expression of osteogenesis-related genes. Antibacterial activityin vitrowas evaluated againstS. aureus(S. aureus) andE. coli(E. coli). The results demonstrated the successful synthesis of the hydrogels, and BMP-2 incorporation optimized the physicochemical properties (a densely packed network, higher compressive strength, and slower degradation) of the BMP-2@HA/ϵ-PL hydrogel, which also showed effective BMP-2 release.In vitroevaluation further indicated that the BMP-2@HA/ϵ-PL hydrogel exhibited favorable cytocompatibility, enhanced osteogenic differentiation of BMSCs due to the synergistic effect of HA and BMP-2, and robust antibacterial effects against bothS. aureusandE. coli. These findings indicate that the injectable BMP-2@HA/ϵ-PL hydrogel features dual antibacterial and osteoinductive functions, offering a promising minimally invasive strategy for peri-implantitis treatment.