Development of Silk based Bio-polymeric Porous Matrices for Tissue Engineering Applications

Abstract

Tissue engineering has emerged as a promising approach for the development of artificial body organs, repair, recover or improve tissue structures and functionality. 3D porous scaffolds possessing biomimicking properties are needed to support the neogenesis of tissues and mass transport of cells, nutrients and metabolic waste. Keeping this in view, the present dissertation work was undertaken for the development of SF based scaffolds with improved surface, mechanical and biological properties that can be used as artificial extracellular matrices for tissue regeneration. The silk fibroin was extracted from B. mori silk cocoon and the process was optimized by Response surface methodology using Box-Behnken Design. Porous SF and SF/PVA) blend scaffolds were prepared by salt leaching process and characterized for morphological (SEM), structural (XRD and FTIR), thermal (DSC and TGA) and mechanical (compressive strength) behaviour. The SF scaffolds were further modified with soluble eggshell membrane protein (SEP) with the aim of improving cell affinity for tissue regeneration. The pore size of the prepared SEP-SF and SEP-(SF/PVA) scaffold were in the range of 250-350µm and porosity of 90-93%. The measured compressive strength of SF and SF/PVA (50:50) scaffold were 279.8 ± 36.2 KPa and 235 ± 67.1 KPa respectively. The existence of soluble eggshell membrane protein on the scaffold surface, structural and thermal stability was confirmed by EDX, XRD, FTIR, DSC and TGA analysis. An increase in compressive strength of the prepared SF scaffolds was achieved by modification with SEP (321.5 ± 42.2 KPa for SEP-SF and247.5± 23.7 KPa for SEP-(SF/PVA) scaffolds). The cell culture study has indicated the significant improvement in cell adhesion and proliferation observed with hMSCs cultured on SF and SF/PVA scaffolds modified with SEP. The cyto-compatibility of the SEP conjugated SF scaffolds was confirmed by in-vivo animal model testing. This study has demonstrated that the biomimic property of SF scaffold can be enhanced by surface modification with SEP. Finally, it is concluded that the SEP conjugated SF/PVA (50:50) has the potential for use as artificial extra cellular matrix particularly for soft and other non-load bearing tissue engineering applications.