Study On Bone Tissue Engineering Based On Sik Fibroin/agarose Composite Scaffold

Silk fibroin (SF) is extracted from the silk or the silkworm. As the earliest natural protein, silk fibroin has been used as surgical sutures for centuries. Silk fibroin itself has excellent mechanical and biocompatible properties, such as non-toxic and safe, degradable, easily chemical modification on the surface according to the requirements. The biological information of silk fibroin has no negative effect on the various cells. The cells are able to adhere on the silk fibroin or silk fibroin-based materials, and also to promote cell proliferation, migration and differentiation to maintain cell morphology. Therefore, silk fibroin has been widely used in tissue engineering as a valuable biomaterial.Agarose (Agar), as one of the core polysaccharide component, has many advantages in comparison with other biological materials. Such as porous, hydrophilic, neutral, chemical stability and so on. Agarose gel is widely used in biological macromolecules electrophoresis due to its good properties. Recently, agarose gradually earns widespread respect as a biological material on tissue engineering applications, especially, has been used on repair and regeneration of the central nervous system areas as an excellent scaffold material.In this dissertation, the composite scaffold material was prepared by the experimental methods of freeze-drying, based on silk fibroin and agarose, the specimen were fabricated with different mass ratio with homogeneous mixture method. The SF/Agarose composites were investigated with SEM, FTIR and TGA to evaluate the characterization of the scaffold. The porosity, density, swelling ratio, water uptaking, mechanical properties and degradation of materials were tested by the related assays in vitro. The results show that, silk fibroin / agarose composite scaffold materials can compensate for the shortcomings of the silk fibroin scaffolds, such problems as fragile, high dissolve loss rate, poor porosity and slow degradation rate. At the same time, the poor mechanical properties of agarose were also improved in the composite scaffold materials. The results suggest that the mass ratio of silk fibroin and agarose is 7 to 3, which exhibits the best properties in porosity, swelling ratio, water uptaking, degradation in vitro and mechanical properties. This study demonstrates that for bone tissue engineering repair, SF / Agarose composite scaffold material has broad application prospects due to many excellent properties.