Viability and Neuronal Differentiation of Neural Stem Cells Encapsulated in Silk Fibroin Hydrogel Functionalized with an IKVAV Peptide

Three-dimensional (3D) porous scaffolds combined with therapeutic stem cells play vital roles in tissue engineering. The adult brain has very limited regeneration ability after injuries such as trauma and stroke. In this study, injectable 3D silk fibroin-based hydrogel scaffolds with encapsulated neural stem cells were developed, aiming at supporting brain regeneration. To improve the function of the hydrogel towards neural stem cells, silk fibroin was modified by an IKVAV peptide through covalent binding. Both unmodified and modified silk fibroin hydrogels were obtained, through sonication, with mechanical stiffness comparable to that of brain tissue. Human neural stem cells were encapsulated in both hydrogels and the effects of IKVAV peptide conjugation on cell viability and neural differentiation were assessed. The silk fibroin hydrogel modified by IKVAV peptide showed increased cell viability and an enhanced neuronal differentiation capability, which contributed to understanding the effects of IKVAV peptide on the behaviour of neural stem cells. For these reasons, IKVAV-modified silk fibroin is a promising material for brain tissue engineering.