Accelerated biomineralization of graphene oxide - incorporated cellulose acetate nanofibrous scaffolds for mesenchymal stem cell osteogenesis

For bone tissue engineering, it requires that the scaffolds have excellent biocompatibility, proper mechanical and osteoinductive properties. Electrospun nanofibers with extracellular matrices mimicking structure have proven to be good scaffolds for bone tissue repairing. Hybrid nanofibers in particular, endow the nanofibers with specific and multiple functionalities, and therefore have attracted increasing interests in the recent years. In this study, we fabricated graphene oxide (GO)-incorporated cellulose acetate (CA) nanofibrous scaffolds by electrospinning technique for enhancement of biomineralization and osteogenic differentiation of human mesenchymal stem cells (hMSCs). The results displayed the average fiber diameter was decreased from 595 to 285nm with the presence of GO from 0 to 1wt%. Furthermore, with incorporation of GO, the Young's modulus of the nanofibers increased in a dose-dependent manner. More importantly, the incorporation of GO led to significantly enhanced adhesion and proliferation of hMSCs on the scaffolds, mainly due to the good biocompatibility and extracellular matrices mimicking structure of the hybrid nanofibers. Exposure of the nanofibers to the simulated body fluid revealed that the biomineralization was improved significantly with the doping of GO in the nanofibers, possibly owing to the more nucleation sites for calcium phosphate provided by GO. The accelerated biomineralization on the GO-CA nanofibers resulted in a markedly increase in the activity of biomineralization-relevant alkaline phosphatase, and thus induced osteogenic differentiation of hMSCs. The current work demonstrated that the GO-CA nanofibrous scaffolds may find potential applications in bone tissue engineering and other regenerative medicine fields.