Poly(ε‐Caprolactone)/Hydroxyapatite Nanofiber Scaffolds With <scp>FGF18</scp> for Cartilage Repair and Dual Modification of Apoptosis and Inflammation in Knee Osteoarthritis

ABSTRACT Osteoarthritis (OA) is a degenerative joint disease linked to pain, deformity, and disability, with oxidative stress playing a central role in its progression. To address this challenge, poly(ε‐caprolactone)/hydroxyapatite nanofibers (PCL/HAp NFs) were fabricated by electrospinning as carriers for fibroblast growth factor 18 (FGF 18). Characterization using FTIR, XRD, and SEM confirmed uniform fibrous structures with an average diameter of 140 ± 20 nm and a sustained release capacity. In vitro studies with human chondrocytes (C20A4) showed improved cell viability, reduced apoptosis, and regulation of pro‐inflammatory cytokines (TNF‐α, IL‐1β, IL‐6). In vivo histological analysis revealed no toxicity in major organs, establishing systemic biocompatibility. Collectively, these scaffolds enhanced cartilage regeneration in vitro while maintaining safety in vivo, demonstrating strong potential for tissue‐engineered treatments to repair articular cartilage damage associated with OA.