Electrospun nanosilicates-based organic/inorganic nanofibers for potential bone tissue engineering

Although growth factors and drugs (BMP-2, dexamethasone, etc.) have been widely used for bone tissue engineering, they have unignored limits such as adverse effects at high concentrations and easy inactivation in vivo. Accordingly, more osteoinductive supplements without side effects should be considered as alternatives in the design of bone tissue engineering scaffolds. Nanosilicate is a bioactive inorganic nanomaterial consisting of hydrous sodium lithium magnesium silicate, which is recently found to be safe and effective for bone induction. In this study, a range of organic/inorganic nanofibrous scaffolds with varied nanosilicate concentrations (0%, 1%, 5%, and 10% w/w to PCL matrix) were successfully fabricated via electrospinning. The tensile properties of the nanofibers were enhanced at low nanosilicate concentrations, and the incorporation of nanosilicates had no influence on cytocompatibility. Besides, in vitro osteogenesis experiments showed that nanosilicates-doped nanofibers were capable of inducing bone formation better than pure PCL nanofiber samples. More importantly, the results of histological and immunohistochemical assessments further revealed that the nanosilicates-enriched nanofibers had a significant potential of ectopic bone formation in vivo, while the pure PCL samples only induced limited osteogenic cues. All these results indicate that the nanosilicates-based organic/inorganic nanofibers may be potentially efficient for bone tissue engineering.