Cryogel tissue scaffold: guided tissue engineering applications using mesenchymal stem cell from Wharton's gel

Title: Cryogel Tissue Scaffold: Guided Tissue Engineering Applications Using Mesenchymal Stem Cells Derived from Wharton's Jelly Aim: Our study is a multidisciplinary research aimed at developing an innovative strategy for the treatment of neurodegenerative diseases and bone defects by examining the neural and osteogenic differentiation potentials of stem cells in a cryogel-based tissue scaffold. By analyzing the effects of the biomechanical and biochemical properties of the cryogel on cell behavior, the aim is to determine the optimal conditions that support bidirectional differentiation. Methods: In the first phase of the thesis study, stem cells were isolated and characterised from Wharton's jelly tissue obtained from the human umbilical cord. In the second phase, synthetic (poly(2-dimethylamino)ethyl methacrylate, PDMA) and natural (carboxymethyl cellulose, CMC) polymeric scaffolds were synthesised using the cryopolymerisation method to create a 3D structure. Additionally, synthetic and natural polymer scaffolds containing graphene oxide (GO) and hydroxyapatite (HAp) were prepared in a 3D structure to promote differentiation. The cryogels were characterised using SEM, TGA and FT-IR analyses, as well as swelling tests. In the third stage, biocompatibility and cytotoxicity tests were performed on the 3D tissue scaffolds and differentiation studies were initiated. Differentiation characterisations were performed using light and confocal microscopy with histological and immunofluorescent staining at different time intervals. Results: The data obtained in the study showed that PDMA and CMC cryogels containing GO and HAp additives in a 3D structure provided significant support for osteogenic and neural differentiation. Cell morphology and staining results corroborated these findings. Furthermore, the effects of the GDE and STP crosslinkers on cell proliferation and structural stability were determined to be different. Conclusion: This thesis contributes to the development of biocompatible and steerable scaffold designs for tissue engineering and regenerative medicine applications, revealing the effects of synthesised 3D PDMA and CMC cryogels, as well as their modified forms, on cell behaviour.