Biomimetic silk fibroin and xanthan gum blended hydrogels for connective tissue regeneration

Combination of naturally occurring materials instead of chemically synthesized products has always been an attractive proposition in the field of tissue engineering. In this study, silk fibroin (SF) and xanthan gum(XG) were physically crosslinked to form biocompatible hydrogels. SF/XG hydrogels were prepared using ultrasonication, which induces β-sheets from random coils in SF solution and allows entrapment of heated XG chains homogeneously in the SF network. It is a novel way of blending SF and XG polymers which avoids the usage of chemical crosslinkers. SF/XG blended solutions were used at different ratios for the hydrogel formation. Scanning electron microscopy (SEM) and micro-computed tomography (MCT) were used for morphological analysis of the interconnected network and porosity of the scaffolds, respectively. Rheological studies were performed to understand the changes in mechanical properties due to the incorporation of XG into SF hydrogels. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of SF and XG moieties in the blend scaffolds. Additionally, thermal Analysis (TGA & DSC) established the homogenous mixture and presence of XG in the SF network without any phase separation. Furthermore, the MTT assay demonstrates the cytocompatibility of scaffolds using L929 fibroblast cells. Thus, fabricated SF/XG scaffolds could mimic natural cartilage ECM by exhibiting enhanced water swelling capacity and suitable porosity along with its cytocompatible studies, indicating its potential application in soft tissue engineering.