Membrana à base de Quitosana com diferentes massas molares: produção, caracterização e bioatividade

Abstract

Chitosan 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.