Osteoblast mineralization with composite nanofibrous substrate for bone tissue regeneration

Several studies are currently ongoing to construct synthetic bone-like materials with composites of natural and polymeric materials with HA (hydroxyapatite). The present study aims to fabricate composite nanofibrous substrate of Chit/HA (chitosan/HA - 80:25) prepared by dissolving in TFA/DCM (trifluoroacetic acid/dichloromethane) (70:30, w/w) for 5 days and electrospun to fabricate a scaffold for bone tissue engineering. HA (25 wt %) was sonicated for 30 min to obtain a homogenous dispersion of nanoparticles within the Chit (80 wt %) matrix for fabricating composite nanofibrous scaffold (Chit/HA). The nanofibres of Chit and Chit/HA were obtained with fibre diameters of 274 ± 75 and 510 ± 198 nm, respectively, and characterized by FESEM (field emission scanning electron microscopy) and FTIR (Fourier transform infrared). The interaction of hFOBs (human fetal osteoblasts) and nanofibrous substrates were analysed for cell morphology (FESEM), mineralization [ARS (Alizarin Red-S) staining], quantification of minerals and finally identified the elements present in Chit/HA/osteoblasts by EDX (energy-dispersive X-ray) analysis. EDX analysis confirmed that the spherulites contain calcium and phosphorus, the major constituents in calcium phosphate apatite, the mineral phase of the bone. Mineralization was increased significantly (P<0.001) up to 108% in Chit/HA compared with Chit nanofibres. These results confirmed that the electrospun composite Chit/HA nanofibrous substrate is a potential biocomposite material for the proliferation and mineralization of hFOBs required for enhanced bone tissue regeneration.