Investigation of the effect of polymeric membranes loaded with Hypericum perforatum oil on scar tissue formation in burn wound healing

Second degree burns, which are damaged by epidermis and dermis, cause certain rates of loss in the dermis. Therefore, wound healing process is usually completed by creating a serious scar. The aim of the thesis is to produce two layer PEG-PCL polymeric membranes loaded with Hypericum perforatum oil known as wound healing in the treatment of second-degree burns. H. perforatum oil is encapsulated by electro-spraying into PEG polymer solution. The electro-spraying PEG solution and the electro-spun PCL solution were deposited simultaneously and mutually in the rotary collector. Distribution of microcapsules within the membrane, membrane surface morphology and interactions of polymers with solvents were determined byScanning Electron Microscope (SEM) and Fourier Transformed Infrared Spectroscopy (FTIR), respectively. Mechanical strength of membraneshave been characterized by standard tensile test. Gas permeability properties were investigated by standard air gas permeability test. The hydrophilicity of the membranes was determined by carrying out contact angle measurements and swelling tests. The time-dependent mass loss of the membranes and the controlled release properties of the H. perforatum oil from membranes over time were investigated in vitro. The antibacterial activity on gram-positive and gram-negative bacterial strains of the membranes was observed by disk diffusion tests. The biocompatibility (WST-1) and cell interaction with cells (incubation, proliferation and apoptosis-necrosis) of membranes, in vitro incubation with L929 mouse fibroblast cell line, were investigated. Finally, polymeric membranes were evaluated for their wound healing properties in a 16-days animal experiment performed by using Wistar Albino rats (n=35). Histochemical and immunohistochemical findings were evaluated statistically. As a result of produced polymeric membranes have the optimum values to be in an ideal wound dressing in terms of various properties (porosity, air permeability, moisture retention capacity, hydrophilicity, elasticity, antibacterial, non-stickiness on wound, biocompatibility etc.). It was confirmed by in vitro and in vivo studies that controlled release of the H. perforatum oil from the membranes as desired to accelerate the healing process by supporting wound healing. However, it is thought that membranes have the potential to reduce long-term scar formation.