الفهرس 
CHAPTER (1): INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Nanofibers of polyethylene oxide (PEO) from an acetic acid aqueous solution were prepared using the electrospinning technique. The experiments were designed using a Taguchi L16 (4^2) orthogonal array. Based on the Taguchi (design of experiment) method, the effects of electrospinning parameters (PEO concentration and acetic acid concentration) on the diameter and morphology of polymer nanofibers were evaluated. Analyses of the experiments for the diameters of the polymer nanofibers showed that the polymer concentration was the most significant factor. For this purpose, the appropriate factor levels were determined as follows: a polymer solution concentration of 3.5% and an acetic acid concentration of 50% to obtain the thinnest nanofibers.
Then, using response surface methodology (RSM), the electrospinning settings were optimized to create achitosan/polyethylene oxide hybrid nanofiber composite with the lowest possible diameter and coefficient of variation (homogeneity). Four parameters—the chitosan/PEO ratio, the applied voltage, the needle-to-collector distance, and the spinning angle—were applied based on central composite design (CCD) in order to assess the impacts of each parameter separately and in combination on the average diameter of nanofibers. At weight ratios of 1:1, 2:1, 3:1, 4:1, and 5:1, polyethylene oxide (PEO) and chitosan (CS) were combined. The RSM model determined that a CS/PEO blend ratio of 2:1 (w/w), a voltage of 25 kV, a distance of 20 cm, and a spinning angle of 45° were required to generate the ideal and most uniform CS/PEO fiber diameter. Under these circumstances, the average nanofiber diameter and homogeneity were found to be 73 nm and 20.5%, respectively, which was higher than the expected values of 71 nm and 15.58%, respectively.
The nanofibers were characterized by SEM, tensile strength, elongation at break, XRD, and TGA/DSC. The optimized electrospun CS/PEO nanofiber mats have demonstrated a remarkable 178.5% increase in tensile strength when compared to PEO nanofiber mats. The thermal stability of the nanofiber was enhanced by blending chitosan and polyethylene oxide. CS/PEO nanofibrous mats loaded with Alagebrium (ALT-711) for wound dressing application were fabricated. CS/PEO nanofiber and CS/PEO nanofiber loaded with ALT-711 were used to investigate whether they could accelerate wound healing in non-diabetic and diabetic rats. The ALT-711-loaded nanofiber dressings accelerated the wound healing process in non-diabetic rats and diabetic rats compared to their counterparts that were treated with ALT-711 un-loaded nanofiber dressings. Rats with and without diabetes found that the ALT-711-loaded nanofiber dressings sped up the healing of wounds more quickly than the rats treated with ALT-711 unloaded nanofiber dressings. The neuropathy was ameliorated when using ALT-711-loaded nanofiber dressings when performing the hotplate test. According to our research, CS/PEO/ALT-711 hybrid nanofibril mats can be used as wound dressings to control diabetic foot ulcers (DFU) and hasten their healing.