Chemically crosslinked guar gum hydrogels: An investigation on the water transport and its relationship with hydrocortisone release.

In this work, we describe the synthesis, the characterization, and the potential application of a pH-responsive guar gum-based hydrogel. The polysaccharide produced permanent hydrogels with improved biocompatibility. In this work, we report the chemical modification of guar gum (with glycidyl methacrylate) and its use, as the main constituent, in obtaining chemically cross-linked hydrogels.

Gold nanoparticles capped with polysaccharides extracted from pineapple gum: Evaluation of their hemocompatibility and electrochemical sensing properties.

In the present work, gold nanoparticles were synthesized through a green route by using, for the first time, polysaccharides extracted from pineapple gum (PG) as the reducing and capping agent. The obtained nanoparticles (AuNPs-PG) were characterized by UV-VIS, FTIR, TEM, FESEM, EDX, XRD, and zeta potential measurements, which confirmed that PG was effective to produce AuNPs with an average diameter of 10.3 ± 1.

Porphyran-capped silver nanoparticles as a promising antibacterial agent and electrode modifier for 5-fluorouracil electroanalysis.

In the present work, the green synthesis of silver nanoparticles (AgNPs) using the sulfated polysaccharide porphyran (PFR) as capping agent and d-glucose as reducing agent is described. PFR was extracted from red seaweed and characterized by employing C NMR and determination of total sugar, protein, and sulfate contents. The obtained AgNPs-PFR were characterized by using UV-VIS spectroscopy, zeta potential determination, FESEM, and TEM, which demonstrated that PFR was effective at capping the AgNPs, yielding stable suspensions.

A sensitive label-free impedimetric DNA biosensor based on silsesquioxane-functionalized gold nanoparticles for Zika Virus detection.

Zika virus (ZIKV) has recently become a global health challenge due to its rapid geographical expansion, since it is associated with serious neurological anomalies such as Guillain-Barré syndrome and microcephaly. Currently, the techniques for ZIKV diagnosis require labor-intensive, expensive and lengthy tests using sophisticated equipment. Moreover, false-positive or false-negative results can occur.

β-D-(1→4), β-D-(1→3) 'mixed linkage' xylans from red seaweeds of the order Nemaliales and Palmariales.

Xylans from five seaweeds belonging to the order Nemaliales (Galaxaura marginata, Galaxaura obtusata, Tricleocarpacylindrica, Tricleocarpa fragilis, and Scinaia halliae) and one of the order Palmariales (Palmaria palmata) collected on the Brazilian coasts were extracted with hot water and purified from acid xylomannans and/or xylogalactans through Cetavlon precipitation of the acid polysaccharides. The β-D-(1→4), β-D-(1→3) 'mixed linkage' structures were determined using methylation analysis and 1D and 2D NMR spectroscopy. The presence of large sequences of β-(1→4)-linked units suggests transient aggregates of ribbon- or helical-ordered structures that would explain the low optical rotations.