Fabrication of bioactive composite scaffolds by electrospinning for bone regeneration

Electrospun scaffolds are widely used for various biomedical applications. In this study, we prepared electrospun bioactive composite scaffolds combining hydroxyapatite, collagen (Col) and a synthetic polymer-PolyActive™-to mimic naturally occurring extracellular matrix for in situ bone regeneration. Human mesenchymal stem cells (hMSCs) adhered and proliferated on these scaffolds. Cells on all scaffold types showed an increased metabolic activity with time. On day 4, the metabolic activity of cells cultured on PolyActive™ (PA)-hydroxyapatite (HA)-Col in 1,1,1,3,3,3-hexafluoro-2-propanolhexafluoro-2-propanol (HFIP) was significantly higher than that of cells grown on PA-Col samples. Furthermore, on day 6, cells on PA-HA-Col in HFIP showed significantly higher metabolic activity than those on PA and PA-Col scaffolds. Quantitative PCR analysis for a panel of osteogenic genes showed statistically significant differences between scaffolds. Cells cultured on PA-HA scaffolds had a significantly higher osteonectin and RunX2 expression compared to those on PA-HA-Col scaffolds. Cells on PA-HA-Col in HFIP scaffolds had significantly higher expression of alkaline phosphatase (ALP) and Col 1 compared to PA and PA-Col scaffolds respectively. The bone morphogenetic protein-2 and S100A4 expression of PA-Col and PA-HA-Col constructs was significantly lower than the basal level expression of cells on PA scaffolds. Although not statistically significant in all cases, cells cultured on PA-HA-Col in HFIP and PA-HA scaffolds had the highest expression for most of the genes analysed. The results of the study demonstrate that bioactive composite scaffolds prepared by electrospinning could find potential use in bone regeneration applications.