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Palma, SI, Rodrigues CA, Carvalho A, Morales PM, Freitas F, Fernandes AR, Cabral JS, Roque ACA.  2015.  A value-added exopolysaccharide as a coating agent for MRI nanoprobes. Nanoscale. (7):14272-14283. AbstractWebsite

Fucopol, a fucose-containing exopolysaccharide (EPS) produced by the bacterium Enterobacter A47 DSM 23139 using glycerol as a carbon source, was employed as a new coating material for iron oxide magnetic nanoparticles (MNP). The coated particles were assessed as nanoprobes for cell labeling by Magnetic Resonance Imaging (MRI). The MNP were synthesized by a thermal decomposition method and transferred to aqueous medium by ligand-exchange reaction with meso-2,3-dimercaptosuccinic acid (DMSA). Covalent binding of EPS to DMSA-stabilized nanoparticles (MNP-DMSA) resulted in a hybrid magnetic-biopolymeric nanosystem (MNP-DMSA-EPS) with a hydrodynamic size of 170 nm, negative surface charge at physiological conditions and transverse to longitudinal relaxivities ratio, r2/r1, of 148. In vitro studies with two human cell lines (colorectal carcinoma - HCT116 - and neural stem/progenitor cells - ReNcell VM) showed that EPS promotes internalization of nanoparticles in both cell lines. In vitro MRI cell phantoms also showed superior performance of MNP-DMSA-EPS in ReNcell VM, for which iron dose-dependent MRI signal drop was obtained at relatively low iron concentrations (12 - 20 µg Fe/ml) and short incubation time. Furthermore, ReNcell VM multipotency was not affected by culture in the presence of MNP-DMSA or MNP-DMSA-EPS for 14 days. Our study suggests that Fucopol-coated MNP represent useful cell labeling nanoprobes for MRI.

Padrão, I, Fernandes CSM, Esteves C, Fernandes T, Pina AS, Roque ACA.  2020.  Versatile and Tunable Poly(Ethylene Glycol)‐Based Hydrogels Crosslinked through the Ugi Reaction. ChemPlusChem. 85(12):2737-2741.
Esteves, C, Palma S, Costa H, Alves C, Santos G, Ramou E, Roque AC.  2022.  VOC Sensing in Humid and Dry Environments, may. 2022 IEEE International Symposium on Olfaction and Electronic Nose (ISOEN). :1–3.: IEEE AbstractPDFWebsite

We report the development of gas-sensing multicomponent hybrid materials to be used under humidified and dried environments without the need of sample preconditioning or heavy signal processing. The easy tunability and the unique characteristics presented by the multicomponent hybrid materials suggests their use in nearterm applications in electronic nose systems able to operate in dry or humidified environments.