Obtenção de nanofibras contendo fucoidana e zeína por electrospinning

Abstract

Nanofibers are gaining prominence due to their unique properties which allow them to be applied in different areas. Among the production techniques, electrospinning stands out for its low cost, simplicity and efficiency in controlling the structure and diameter of the fibers, making it possible to manufacture nanofibers from a variety of materials, such as polysaccharides from macroalgae and natural proteins. Fucoidans, a class of sulphated polysaccharides extracted from brown algae, have attracted attention in biotechnological research due to their diverse bioactivities. Zein, a natural and nontoxic protein, is recognized as a safe polymer and comes from renewable resources. Considering the above, the aim of this work was to develop nanofibers from polymeric solutions of zein with the addition of fucoidan extracted from brown algae using the electrospinning technique. Fucoidan was extracted from the macroalga Durvillaea antarctica, but due to the low yield obtained, the extraction was not viable for the production of nanofibers on a large scale. To overcome this limitation, we opted to use commercial fucoidan purchased from Sigma-Aldrich®, which allowed us to continue producing nanofibers. Polymeric solutions of Zein at 30% (w/v) and fucoidan (0%, 25%, 30% and 35%) were produced and their electrical conductivity and viscosity were analyzed. The highest viscosity was observed in solutions with 25% and 30% fucoidan, while electrical conductivity showed little variation with increasing fucoidan concentration. Contact angle analysis indicated a hydrophilic characteristic of the polymer solutions, which may be favorable to cell adhesion and proliferation. The Fourier transform infrared spectra of the nanofibers revealed bands characteristic of the materials used, and the X-ray diffraction analysis showed the amorphous nature of the fibers. The size distribution analysis showed an average size of 540 ± 130, while the nanofibers incorporated with 25% and 30% fucoidan had a ribbon shape with an average size of 234 ± 54 nm and 276 ± 54 nm. It was therefore possible to observe that the addition of fucoidan to the polymer solution significantly improved the morphology of the fibers, changing them to a ribbon shape, as well as reducing their diameter, when compared to the control fiber, which makes the study of its biological activity viable, given that it has already been reported in the literature that fibers smaller than 100 nm showed toxic responses in vitro. In the cytotoxicity tests with 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and sulforhodamine B, the nanofibers showed no cytotoxic effects on healthy mouse fibroblast cells at the analyzed times of 24h and 48h, which makes it feasible to continue the biological studies, such as the application as a healing adhesive for skin in future stages of this project.