Wounds are defined as skin damage caused by external factors, surgery or pathological conditions (diabetes, vascular diseases). If wound healing lasts longer than 8 weeks, we are talking about chronic wounds, which significantly impair the quality of life of those affected and represent an increasing health and economic social problem. Lower concentrations of growth factors are observed in chronic wounds compared to acute wounds, suggesting that their deficiency could be a major risk factor for the development of chronic condition. The aim of the master's thesis was to isolate growth factors from adherent mononuclear blood cells, isolated from peripheral blood in order to potentially utilize them for wound healing. Mononuclear blood cells were isolated from donor blood filters by attaching them to a plastic substrate and using a nylon fibre column, to extract adherent blood cells. The latter were hypoosmotically activated and then the influence of released cytokines or growth factors on the proliferation of human keratinocytes was studied in vitro. We have shown that we have succeeded in obtaining growth factors that significantly influence the growth and proliferation of keratinocytes and thus accelerate wound healing. By determining the amount of growth factors using flow cytometry, we were able to demonstrate that the extraction of growth factors was more successful when we used a nylon fibre column to adhere mononuclear cells. Since cytokines or growth factors are proteins and their stability in vivo is limited, appropriate delivery systems are crucial for their effective uptake into the body. Since we wanted to produce a wound dressing with growth factors, we chose nanofibers as a delivery system. For this purpose, using the electrostatic twisting method, we tried to produce hydrophilic nanofibers from chitosan or alginate, with the addition of polyethylene oxide. We did not succeed in producing chitosan and polyethylene oxide nanofibers. However, we were successful in producing nanofibers from alginate and polyethylene oxide. By optimizing the process parameters, we produced smooth nanofibers, without knots. We then investigated their stability in water and found that nanofibers made of alginate and polyethylene oxide are not stable in purified water, as they dissolve immediately. Therefore, they were ionically crosslinked with a CaCl2 solution. The cross-linked nanofibers retained their fibrous structure in purified water for at least 72 h, indicating that they would be suitable for the potential production of wound dressings with incorporated growth factors.
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