Development of electrospun nanofibrous silk fibroin based scaffolds for bone tissue engineering

Abstract

The present research focuses on the development of a novel silk fibroin based 3D artificial nanofibrous structure for its usage as a scaffold in bone tissue engineering. Silk fibroin (SF) was extracted from eri and tasar silk cocoons by degumming method and a spinnable SF blend was developed by selection of an optimal binary solvent system i.e. chloroform and formic acid (60:40 w/v). Randomly oriented nanofibrous scaffolds were developed from SF blend by electrospinning. The morphological characteristics of the developed scaffolds were studied by SEM, TEM and AFM. The structural and thermal properties were investigated by XRD, FT-IR, TGA, DSC and TM-DSC. The scaffolds were also characterized for surface property (% water uptake and contact angle measurement) and mechanical property. In vitro cell culture study confirmed the excellent cell supportive property of the scaffold in terms of cell attachment, cell proliferation and cellular metabolic activity using hMSCs derived from umbilical cord blood. The scaffold possessed good osteogenic property as confirmed by ALP, biomineralization, osteocalcein and RUN X 2 expression. All these results suggest that the developed SF blend derived from eri and tasar can be used as a base polymeric scaffold material for tissue engineering application including bone tissue regeneration. Surface property and osteogenic differentiation ability of the nanofibrous SF blend scaffold were further improved by the deposition of nanohydroxyapatite (nHAp) over the surface of the scaffold by surface precipitation method and thus, SF/nHAp composite scaffold was developed. Similar to SF blend scaffold, the composite scaffold was also characterized for surface, mechanical and biological property and the results were compared with that obtained with pure SF blend scaffold. It was demonstrated that the developed composite scaffold showed improved surface property and osteogenic differentiation ability as compared to SF blend as well as the widely used SF scaffold derived from Bombyx mori. Hence, it can be concluded that the developed SF/nHAp nanostructure is a promising scaffold in bone tissue engineering application.