Kontrollü Bor Salan Biyobozunur Yara Örtülerinin Geliştirilmesi ve Dermal/Mukozal Rejenerasyonda Kullanımlarının Araştırılması

Abstract

The following thesis presents the development of fiber matrices containing boron (B), which has therapeutic effects in wound healing, and montmorillonite (MMT) as nanoclay. These are specifically used in the treatment of oral mucositis and foot ulcers, which are the most common of oral mucosal and skin wounds, respectively. This study aimed to evaluate the interaction of fiber matrices containing B and MMT with keratinocyte and fibroblast cells which are involved in wound healing process. In the first phase of the thesis study, the effects of different concentrations of boron (a therapeutic ion) were evaluated in human endothelial, keratinocyte and fibroblast cells on cell culture dishes for their wound healing potential. The results showed that the vascular-forming capacity of endothelial cells increased at 10 and 20 μg/mL B concentrations, and keratinocyte and fibroblast cell migration was somewhat accelerated. At the same time, this amount of boron supported the proliferation of fibroblast cells. An addition of up to 20 μg/mL of boron to cell culture media had no significant effect on the morphology and viability of keratinocytes and fibroblasts. In the second stage of the study, boron adsorption was carried out on montmorillonites. On average, 2847 μg/g MMT of B was adsorbed and it was determined that approximately 87% of the boron was released in the first 24 hours. In the third step, PLGA (poly(lactic-co-glycolic acid)) fiber matrices containing MMT and B-doped MMT (B-MMT) were produced by electrospinning and cultured keratinocyte cells. XRD analysis ensured MMT contribution to the fiber matrices. It was determined that PLGA fiber matrices doped with 20 percent B-MMT continued to release boron for 9 days. However, the shrinkage behaviour of PLGA-based fiber matrices caused a decrease in porosity and a rigid structure, negatively affecting the success of cell cultures. In the last stage of the study, PLA (poly(lactic acid)) based fiber matrices with doped MMT and B-MMT were produced, characterized and cell culture studies were conducted. The effects of different amounts of B-MMT additives on the morphology, degradation behavior and chemical/physical properties of fiber matrices were evaluated. Antibacterial tests have shown that 10% B-MMT added PLA matrices have a bactericidal effect on gram-positive bacteria S.aureus strains. It was determined by a mucoadhesion test that PLA fiber matrices containing 10% B-MMT were more mucoadhesive than the other groups. In cell culture studies with keratinocytes and fibroblast cells, the proliferation of keratinocytes was highest in the PLA group. In fibroblast cells, the highest proliferation values were achieved in PLA-based fiber matrices containing 10% MMT and B-MMT. Live/dead staining analyses revealed that dead cells were more intense in the PLA group for both cell types. Expressions of genes important for wound healing were examined by RT-PCR. It was determined that gene expressions of vascularization-related growth factors of keratinocytes increased in B-MMT doped PLA fiber matrices, and simultaneously, the proliferation capacity of the cells was preserved. The increase in the expression of genes associated with extracellular matrix production particularly demonstrated the most significant effect of B-MMT doped PLA fiber matrices on fibroblasts. In light of the findings, the study suggests that B-MMT doped PLA fiber matrices positively affected the wound healing response. Thus, B-MMT doped PLA fiber matrices might has potential as a bioactive wound dressing with potential therapeutic function for both skin and oral mucosa regeneration.