A one-step polyphenol-based functionalization strategy of dual-enhanced antibacterial and osteogenic surfaces

Infected bone defect is a critical problem in clinical practice of orthopedics. To solve this problem, implants with dual-functional surfaces which possess both antibacterial and osteogenic properties have extensive applications. However, there remains a pressing need to develop a convenient strategy for preparing such surfaces facilely. In this study, we reported a novel one-step polyphenol-based surface functionalization strategy for preparing two fibrous membranes with antibacterial and osteogenic capabilities. The formation of RGD-HHC36 (RH) or RGD-polyhexamethylene guanidine (RP) coating was fabricated by Michael reaction with poly (tannic acid) (PTA) to produce dual-functional fibrous membranes (PLA-RH and PLA-RP, respectively). The surfaces of PLA-RH and PLA-RP exhibited increased roughness and hydrophilicity. In vitro tests revealed that PLA-RH and PLA-RP could eradicate over 99% of clinically common pathogenic bacteria while exhibiting significant improvements in the adhesion, proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Moreover, RNA-Seq analysis revealed that the up-regulation of Chrdl1 played a key role in promoting ossification through activation of the CHRDL1 - BMP4 pathway. The favourable in vivo anti-infection and osteogenesis-promoting performances were demonstrated in an infected bone defect model. PLA-RH and PLA-RP inhibited bacterial infection in the early stage, and enhanced osteogenesis in the late stage. This study provides a facile and universal strategy for designing and fabricating dual-functional surfaces for antibacterial application and tissue regeneration simultaneously.