Bioactive Nanocomposite Scaffolds by Melt Electrospinning of Poly-ε-Caprolactone/Polyethylene Oxide/Polyethylene Glycol-Hydroxyapatite Blends for Bone Tissue Engineering

Bone defects that are beyond the body's natural repair capacity remain a significant challenge in bone tissue engineering. In recent years, various synthetic materials have been introduced as potential alternatives for repairing these defects, but most of them have limitations. In particular, calcium phosphate cements (CPCs) possess desirable bioactivity but poor mechanical strength. Polymethyl methacrylate (PMMA) exhibits high structural stability but lacks adequate degradability and bioactivity. These obstacles highlight the need to develop materials that balance structural integrity with biological function. In this study, poly-ε-caprolactone/polyethylene oxide/polyethylene glycol (PCL/PEO/PEG) nanocomposite scaffolds containing hydroxyapatite nanoparticles (nHA) were fabricated using solvent-free melt electrospinning and assessed for their physical, chemical, and biological properties. Three masterbatch systems (nHA@PCL, nHA@PEO, and nHA@PEG) and varying percentages of nanoparticles (1, 5, 10, and 20%) were investigated. The results showed that the nHA@PCL system resulted in better stability of nanoparticles after immersion, and ternary blend (PCL/PEO/PEG) scaffolds, especially Ternary-nHA10@PCL (PCL/PEO/PEG-nHA10@PCL), provided the highest hydrophilicity, cell adhesion, cellular metabolic activity, cell proliferation by DNA counting, and calcification deposition. Overall, blending nHA with PCL as the main component, along with the presence of hydrophilic polymers such as PEO and PEG, is an effective strategy for simultaneously promoting human osteoblast and vascular endothelial cell growth and activity, and Ternary-nHA10@PCL is introduced as the optimal option.