Monografias, Dissertações e Teses
URI permanente desta comunidadehttps://repositorioacademico.universidadebrasil.edu.br/handle/123456789/1
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Item Membranas de quitosana associada a cúrcuma: produção, caracterização e avaliação da biocompatibilidade e efeitos antimicrobianos(Universidade Brasil, 2024) Macedo, Daniela Bezerra; Assis, Lívia; Pavinatto, AdrianaSkin wounds cause pain, functional impairment and quality of life and are associated with significant economic impact. Chitosan and turmeric have properties that have the potential to promote the repair of skin wounds. However, the relationship between medium molar mass chitosan associated or not with turmeric, as well as the physicochemical properties and biological effects have not yet been elucidated. Thus, the objective of the present study was to produce, characterize and evaluate, in vitro, the cytotoxicity of a membrane based on medium molar mass chitosan associated or not with turmeric in a fibroblast line (L929), as well as the antimicrobial potential for Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Three chitosan based membranes of medium molar mass were produced using the casting (solvent evaporation) thin film formation technique: 1% chitosan-based membrane (m/v; QM); chitosan associated with 30% glycerol (m/m in relation to the mass of chitosan; QMG); chitosan associated with 30% glycerol and 1.5% turmeric (m/m in relation to the mass of chitosan; QMGC). To characterize the physicochemical and morphological properties of the membranes, infrared absorption spectroscopy (FTIR), contact angle and thickness measurements were used. To evaluate cell viability/cytotoxicity, L929 cells were used at a concentration of 1x104 using the alamarBlue® and Picrogreen assay; To evaluate the antimicrobial potential, strains of Gram-positive bacteria S. aureus and Gram-negative bacteria E. coli were used at a concentration of 1 x 108 by evaluating the inhibition halo. The results show that all membranes were sustainable, homogeneous and flexible, with the QMG and QMGC membranes being the most flexible and most hydrophilic compared to the QM membrane. Vibrational bands were observed for chemical groups of chitosan and glycerol in all membranes. Regarding the evaluation of cytotoxicity, all membranes showed higher values of metabolic activity/viability, as well as a greater proliferation of fibroblast cells in the experimental period of 72 hours when compared to 24 hours of culture. Furthermore, all membranes presented an inhibition halo to the tested microorganisms, with the QMGC membrane promoting the greatest inhibition halo. With the results obtained in the present study, it is possible to confirm the reparative potential of chitosan-based membranes of medium molar mass, as well as their antimicrobial potential, with emphasis on the membrane associated with turmeric. However, further studies are needed to elucidate the use of these membranes as potential biomaterials for bioactive wound dressings.Item Avaliação in vitro do potencial antimicrobiano e da viabilidade celular de diferentes concentrações de Ozonioterapia(Universidade Brasil, 2022) Morais, Jynani Pichara; Assis, Lívia; Tim, Carla RobertaCutaneous wound is a clinical condition with high prevalence and represents a public health problem. Although ozone therapy (O3), ozone therapy, is widely used in clinical practice due to its antimicrobial and restorative effects, evidence on ideal dosimetries is still scarce. Thus, the aim of the present study was to evaluate and compare, in vitro, the cytotoxicity of different concentrations of ozone therapy in keratinocyte (NOK) and fibroblast (L929) lines, as well as the antimicrobial potential for Staphylococcus aureus (S.aureus) and Escherichia coli (E. coli). NOK and L929 cells were seeded at a concentration of 1x104 and strains of gram-positive bacteria S.aureus and gram negative bacteria E. coli at a concentration of 1x108 and divided into 7 experimental groups treated with ozone at doses of 0 (G0), 5 (G5), 10 (G10), 20 (G20), 30 (G30), 40 (G40) and 50 μg/mL (G50). The effect of ozone on cell viability/cytotoxicity was determined using the alamarBlue® assay, the Live/Dead® assay, and morphometric analysis of the percentage of live and dead cells. The effect of the gas on the microorganisms was evaluated by counting the colony forming unit (CFU). The results obtained show that ozone at concentrations of 5, 10 and 20 μg/mL presented the highest viability values of NOK (keratinocytes) and L929 (fibroblasts) cells, as well as a higher density and percentage of live cells in the experimental period of 72 hours when compared to other concentrations. However, it was not possible to observe the difference between the percentage of dead cells between the experimental groups. Furthermore, ozone promoted a reduction in CFUs at all concentrations tested. With the results obtained in the present study, it is possible to confirm the reparative potential of ozone therapy in a dose-dependent response, as well as its antimicrobial potential. However, studies are needed to elucidate the molecular mechanisms by which it exerts such biological effects.