Engenharia Biomédica
URI permanente para esta coleçãohttps://repositorioacademico.universidadebrasil.edu.br/handle/123456789/915
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Resultados da Pesquisa
Item Utilização de quitosana e piperina na alimentação de animais: análise da eficácia no reparo de lesões cutâneas em ratos(Universidade Brasil, 2024) Carvalho, Conceição de Maria Aguiar; Costa, Adriana Pavinatto da; Tim, Carla RobertaThe skin, known as the largest organ in the human body, stands out for its unique role in maintaining the integrity of the organism. Disruptions in the epithelial layers are called skin lesions or wounds. Wound repair consists of a mechanism consisting of the phases of hemostasis and inflammation, proliferation and remodeling, starting immediately after the injury occurs. The need for efficient therapy to care for a population affected by injuries is a growing challenge that demands innovative, efficient and affordable strategies. In this scenario, the present study aims to the evaluation of the association of the antimicrobial and reparative action of Chitosan (Chi) with the anti-inflammatory action of Piperine (PIP) in the process of repairing skin lesions. To this end, lyophilized microparticles of Chi and PIP were produced and characterized for subsequent administration to animals with lesions induced via gavage. After freeze-drying, 2.4g of QUI and 2.7g of Chi/PIP were obtained. The spectra obtained through Fourier Transform Infrared Spectroscopy (FTIR) showed vibration bands characteristic of the chemical groups that form the material and corroborate the literature. Scanning electron micrographs (SEM) of the powdered samples showed particles with relatively rough surfaces, while the freeze-dried samples presented thinner surfaces with greater surface area. Both materials do not present a thermal degradation process at temperatures below 60ºC, indicating that they remain active (not degraded) when subjected to animal body temperature. The qualitative analysis of the lesions, obtained from in vivo results, revealed no signs of necrosis, odor or liquid in the lesion cavity, nor did it indicate the presence of fibrosis. The morphometric analysis of the wound repair index showed no statistically significant difference between the experimental groups in all periods studied. Likewise, through histological analysis of the injured tissue, it was not possible to observe significant changes between the experimental groups.Item Desenvolvimento de biossensor eletroquímico para detecção de lactato(Universidade Brasil, 2021) Torres, Samuel Guerra; Costa, Adriana Pavinatto da; Costa, Mardoqueu Martins daThe development of new sensory platforms is of great interest to the field of biosensors, especially those with low cost and high reproducibility characteristics. In this context, the present study aimed at the production and characterization of a biosensor platform composed of films produced by the physical adsorption self assembly technique (Layer-by-Layer - LbL) using chitosan and AuNps@PTS (gold nanoparticles stabilized with PTS polymer – a sulphonated polythiophene derivative). Subsequently, the platform formed was used for immobilization of the enzyme lactate oxidase (LOx) and detection of lactate. The films were formed in different numbers of bilayers and characterized by spectroscopic measurements of ultraviolet absorption (UV-Vis) and fluorescence, and electrochemical measurements. The LOx enzyme was immobilized on two LbL film bilayers through dripping and subsequent cross linking performed with the addition of glutaraldehyde. The detection of lactate was performed through cyclic voltammetry (VC) measurements on standard samples. The results show that film growth was relatively homogeneous, and until the fourth bilayer the absorption intensity increased linearly with the number of bilayers. CV measurements showed that the electrode modified with two film bilayers allows greater charge transfer, being the platform chosen for immobilization of the LOx enxima and detection of lactic acid. Voltammograms showed that the presence of the LOx enzyme hinders charge transfer and that its immobilization was effective. Detection measurements show that the developed platform is suitable for detecting lactate, and the analytical signal presented a linear regime between the increase in the anodic current magnitude and the increase in the lactate concentration, in the range of 0.5 to 30 mM of lactate. The platform used was able to detect human sweat lactate at different times and intensities of physical exercise, with detection limits close to those found in the literature.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 Membrana à base de Quitosana com diferentes massas molares: produção, caracterização e bioatividade(Universidade Brasil, 2023) Macedo, Juliana Bezerra; Pavinatto, AdrianaChitosan is a polysaccharide widely used in biomedical applications due to its bioactivity, which is often related and can be modulated by its structural characteristics. Among these characteristics, molar mass is one that influences its action and, as cited in the literature, it may have different activity depending on the microorganism studied. In this context, this study aimed to evaluate the bioactivity of four types of membranes formed by pure high (QAMM) and low (QBMM) molar mass chitosans associated with turmeric (QAMM + turmeric and QBMM + turmeric), produced using the technique casting thin film formation (solvent evaporation). For physicochemical and morphological characterization of the membranes, thickness measurement techniques, absorption spectroscopy in the infrared region (FTIR) and contact angle were used. To carry out the microbiological tests, strains of the fungus Trychophyton rubrum, the gram-positive bacterium Staphylococcus aureus and the gram-negative bacterium Escherichia coli were used, and the bioactivity of the membranes was evaluated through the inhibition halo formed. To evaluate cell viability/cytotoxicity, fibroblast cell lines (L929) were used at a concentration of 1x104 using the alamarBlue® and Picrogreen assay. The methodology used to manufacture membranes was successful, making it possible to obtain self-supporting and homogeneous membranes, with thicknesses ranging from 35 to 56 μm. FTIR spectra show the main vibrational bands for chemical groups in chitosan. Contact angle results show that membranes containing turmeric are more hydrophilic than pure chitosan. The membranes did not show antimicrobial growth inhibition properties against the tested microorganisms. However, the presence of an inhibition halo was verified under bacterial cultures in tests using the membrane preparation solutions, with the QBMM and QBMM + turmeric solutions showing a greater inhibitory effect. The membranes produced did not present a cytotoxic effect, as they induced an increase in cell proliferation. In general, QBMM+ turmeric provided greater cell proliferation compared to that observed using other membranes. The results of the present study suggest that the membranes produced are promising materials for application in tissue engineering, favoring their manufacturing and optimal use.