Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Peptide Hydrogels Containing Cell Attachment Molecules(Izmir Institute of Technology, 2019) Uysal, Berk; Top, Ayben; Top, AybenIn this study, peptides with sequences and notations as KLELKLELKLEL (KLEL), KLDVKLDVKLDV (KLDV), KLDVKLDVKLKV (KLKV1), KLKVKLDVKLKV (KLKV2), KLKVKLKVKLKV (KLKV3) were synthesized using solid phase peptide synthesis (SPPS) method based on Fmoc chemistry. Reverse phase HPLC and MALDI-TOF mass spectroscopy characterization methods were used to assess the purity of the peptides. Three different synthesis procedures were tested, and it was found that employing DMF:DMSO at 1:1 ratio as a solvent increased purity of the resultant peptide. FTIR results indicated the presence of expected β-sheet secondary structure, as well as an interference band from TFA salts for all of the peptides. All the peptides formed hydrogels at pH 7.4 with 1 wt% concentration in deionized water (DIW). AFM results of these hydrogels indicated that KLKV1 and KLKV2 had fibrous morphology with a width of 5-20 nm and 7-18 nm respectively. KLDV and KLKV3 peptide hydrogels, on the other hand, exhibited globular structures, having sizes with 15-50 nm and 8-15 nm, respectively. Storage moduli (G’) of these hydrogels in DIW were obtained as ~860 ± 150 Pa, ~260 ± 60 Pa, ~210 ± 30 Pa and ~1850 ± 200 Pa for KLDV, KLKV1, KLKV2 and KLKV3 respectively. Of these peptides, only HCl salt of KLDV and KLKV1 peptides more readily formed hydrogels in PBS but at 1.5 wt% concentration. G’ values of these KLDV and KLKV1 hydrogels were determined as ~1810 ± 850 Pa and ~700 ± 230 Pa, respectively. Cell proliferation tests (CCK-8 assay) of KLDV and KLKV1 hydrogels were performed by using L929 mouse fibroblast cells. Empty wells (TCPS) were used as a control group. Cell proliferation was observed to be comparable for both select hydrogels and empty wells, suggesting possible applications of these hydrogels in tissue engineering.Master Thesis Ultra-Porous Interconnected Hydrogel Structures for Tissue Engineering Applications(Izmir Institute of Technology, 2018) Yıldız, Büşra; Yıldız, Ümit Hakan; Arslan Yıldız, AhuTissue engineering aims to repair and regenerate tissue and organs with functional defects. The most significant developments in tissue engineering emerging as modification of the scaffold used to mimic native extracellular matrix (ECM) and support cell proliferation and differentiation. Hydrogel-based biomaterials are one of the most utilized materials as scaffold providing excellent chemical, physical/biophysical properties, high biocompatibility and functionality necessary for the applications in tissue engineering. In this study, Gelatin methacryloyl hydrogel (GelMA) and Gelatin-urethane hydrogels (GelatinK) are successfully synthesized as scaffold material for tissue engineering applications. Gelatin is modified with methacrylic anhydride for GelMA polymer and with 2-isocyanatoethly methacrylate for GelatinK polymer. The hydrogels of these two novel polymer are produced with photopolymerization reactions in aqueous media using Irgacure 2959 as redox initiator. Hydrogels are freeze-dried to remove solvent in the gel matrix and then they immersed in distilled water to reach equilibrium swelling ratio. The swelling capacity of GelMA hydrogels ranges between 1200 and 300% whereas GelatinK hydrogels has swelling capacity in between 1900-380%. Also, morphology of the hydrogels were investigated with Scanning Electron Microscopy (SEM). GelMA hydrogels has pore sizes between 142-14 µm while GelatinK hydrogels has between 160-56 µm pore sizes. The cell viability assay were also conducted using GelMA and GelatinK hydrogels. The results showed that both hydrogels provide high viability as compared to 2D control assay.