Investigation of the effect of peptide gels on neural differentiation of olfactory mucosal mesenchymal stem cells

There is no effective treatment for central nervous system diseases. In particular, the incidence of neurodegenerative diseases increases day by day and effective treatment methods cannot be developed. Neural regeneration can be achieved to a larger extent by tissue engineering approaches, such as supporting isolated cells with neurotrophic factors and extracellular matrices. Stem cells, because of their unique features, such as self-renewal and differentiation, have lately become a focus in neural tissue engineering applications. Consideration of isolation challenges of neural stem cells has brought mesenchymal stem cells to the agenda. In particular, it has been suggested that olfactory mucosal mesenchymal stem cells (OM-MSCs) are predisposed to neural differentiation. Based on this information, OM-MSCs isolated from young rats were used in this thesis study. The neural differentiation of the isolated cells was supported by a self-assembled peptide gel, which is one of the tissue engineering approaches. The self-assembled PuraMatrixä peptide gel, which serves as an extracellular matrix, was previously shown to support neural regeneration on oligodendrocytes due to its ability to support the neural cell differentiation and proliferation. Therefore, neural differentiation of OM- MSCs was supported by PuraMatrix peptide gel and various neural growth factors supplied in the culture medium. In summary, in this thesis, in vitro neural differentiation capacities of OM-MSCs in 2D and 3D, and the effects of PuraMatrix peptide gels in their differentiation were investigated. Characterization of differentiation was performed by: immunohistochemical staining using beta-III-tubulin, synaptophysin, GFAP and O4 neural markers, real-time polymerase chain reaction using beta-III-tubulin, synaptophysin and tyrosine hydroxylase neural markers, and electron microscopy imaging for determination of neural morphology. According to the experimental results, it was determined that PuraMatrix peptide gel supports the differentiation of the OM-MSCs toward neuron- like cells. Keywords: OM-MSC, puramatrix, neural differentiation, neural tissue engineering