(Monday’s/9.30H/CEB anfitheatre)
João Machado, Surface modification of bacterial cellulose by plasma treatments
Bacterial cellulose (BC) is a biocompatible material with unique properties, such as ultra-fine fibre network and high strength that makes it an attractive material for biomedical applications. This work in focused in the surface modification of BC with plasma in order to induce surface modifications and improve cell adhesion and proliferation. The plasma treatment increased the roughness and surface chemistry, as noticed by the presence of nitrogen. The obtained results suggest that the effects on BC surface properties are dependent on the gas mixture, time and flux. The alterations on current intensity didn’t influence significantly the obtained results. The MTS Cell Proliferation Assay results showed that the Ar plasma treated BC cause cell death after 48 h of cell seeding, the results also showed that the effect previously described is reversed by the presence of N2 on the treatment gas.
João Silva, Characterization of yeast metabolic state using LWUV-VIS-SWNIR spectroscopy
2nd year student
Spectroscopy is widely used in biological sciences, being applied to liquids, pastes, powders, films, fibers, gases and surfaces. It makes it possible to characterize proteins, peptides, lipids, membranes and carbohydrates in pharmaceuticals, foods, plants or animal tissues. It can also provide detailed information about the structure and mechanism of action of molecules. In this work the use of LWU-VIS-SWNIR spectroscopy is explored as an high-throughput, non-destructive technique associated to multivariate calibrations, for characterization of the metabolic state of different yeast strains, under the presence of stress-inducing compounds such as: ethanol, 1-butanol, isopropanol, 2-methyl-2-butanol, 2-furaldehyde and 5-hydroxymethyl-furfural. This technique was able to detect key parameters such as: optical density, pH as well as the concentrations of ethanol, CO2, glycerol, acetic acid, 5-hydroxymethyl-furfural and furfural. Results show that LWU-VIS-SWNIR spectroscopy is a robust technique holding potential to characterize and monitor yeast metabolic state under different stress conditions.
