Investigation and Characterization of Gold Nanoparticle-Loaded Poly(ε-caprolactone) Electrospun Nanofibrous Scaffolds with a Polydopamine Coating for Bone Regeneration

Electrospun nanofibrous scaffolds have attracted considerable attention in the field of bone tissue engineering, but most polymer-based scaffolds demonstrate restricted efficacy in promoting bone regeneration. In this study, a novel gold nanoparticles (AuNPs)-modified poly(ε-caprolactone) (PCL) electrospun nanofibrous scaffold (PCL/PDA@AuNPs) was developed via electrostatic interaction with a polydopamine (PDA) coating. The AuNPs, with an average diameter of 45 nm, exhibited excellent biocompatibility and enhanced alkaline phosphatase (ALP) activity in rat bone marrow mesenchymal stem cells (rBMSCs). The immobilization of AuNPs on the scaffold surface improved its hydrophilicity, mechanical properties, and biocompatibility. Furthermore, rBMSCs cultured on the PCL/PDA@AuNPs scaffolds showed enhanced osteogenic differentiation, as evidenced by a significant upregulation of ALP activity and osteogenic gene expression. In vivo experiments using a critical-sized rat calvarial defect model demonstrated that the implantation of PCL/PDA@AuNPs significantly promoted new bone formation and collagen deposition while concurrently mitigating inflammatory responses. Overall, these findings suggest that the AuNP-loaded nanofibrous scaffolds are highly promising for bone tissue engineering applications.