Biocompatibility and physicochemical characteristics of poly(Ɛ-caprolactone)/poly(lactide-co-glycolide)/nano-hydroxyapatite composite scaffolds for bone tissue engineering

This paper reports a novel method to prepare PCL/PLGA/HA (w/w=6/4/2) bone tissue scaffold through melt-blending and particle-leaching. The ultrastructural and physicochemical properties of the scaffolds were studied by SEM, FTIR, XRD and TGA. Its porous rate and average size were 75.74±1.21% and 179.07±0.75μm, tensile strength and compressive strength were 147±5MPa and 47±2MPa. The 24-week degradation rate was 32.31±1.93%. Human mesenchymal stem cells were cultured in the scaffolds for 14–21days in vitro. The results indicate that scaffolds can promote hMSCs proliferation and osteogenesis by enhancing the expression of ALP. The expression of the bone-related genes Runx2, OPN, OCN, BMP-2, collagen I, integrin a1, integrin b1, and SLP was markedly upregulated, suggesting that this scaffold can promote hMSCs differentiation, proliferation and maturation to osteoblasts. In vivo experiments, the scaffolds were implanted in a rabbit skull-defect model. Micro X-ray 3D imaging, HE, and immunohistochemistry revealed that the scaffold materials are degradable and also display excellent biocompatibility, along with the capacity to induce bone regeneration. Therefore, PCL/PLGA/HA scaffold materials would be promising in the repair and regeneration of non-weight-bearing bones.