Albumin release from a brain-resembling superabsorbent magnetic hydrogel based on starch

Superabsorbent hydrogels based on polysaccharides for application in agriculture as soil conditioner and nutrient carrier: A review

“…To address the challenges associated with the lack to ability to produce mechanically stable hydrogels from not chemically modified polysaccharides, an approach based on a chemical reaction that involves linking carbon-carbon double bonds to polysaccharide chains has been widely used [59]. Many polysaccharides, including those of complex structures, such as pectin [60], cashew gum [28], Arabic gum [61] and starch [62], have been modified through vinyl groups incorporation in order to produce SH. The idea of modifying polysaccharides by addition of vinyl groups is far being new, although the mechanisms involving methacrylate addition reaction through glycidyl methacrylate (GMA) were recently clarified.…”

Starch-based microspheres for sustained-release of curcumin: Preparation and cytotoxic effect on tumor cells

“…The insertion of methacrylate groups from GMA on different polysaccharides backbones is a well-known methodology used to form crosslinked networks (Guilherme et al, 2012;Thompson et al, 2006). The chemical reaction of GMA with the polysaccharide has been described in the literature by two possible mechanism routes.…”

“…This route predominates when the reaction is carried out in a protic solvent, as water. The epoxy ring-opening reaction is known as slow and irreversible, fact that could increase its effectiveness (Guilherme et al, 2012;Thompson et al, 2006). Fig.…”

“…k is a constant of proportionality that relates the characteristics of the polymeric network and the solute at a given solvent. n is a parameter that depends on the diffusion mechanism and it has different conceptual meaning depending on the geometrical shape of the release device (Guilherme et al, 2012;Thompson et al, 2006). For a spherical shape (which corresponds to the geometry of our microspheres) the value of the parameter n could be interpreted in the following way: (i) n = 0.43 for Fickian diffusion or Case I (the diffusion rate is slower than the relaxation of the polymeric chains); (ii) 0.43 < n < 0.86 for anomalous transport, contribution of Fickian diffusion and controlled relaxation (the diffusion rate and the relaxation of the polymeric chains are similar), (iii) n = 0.86 for zero order or Case II (the diffusion rate is faster than the relaxation of the polymer chains) and (iv) n > 0.86 for super Case II (contribution of the macromolecular relaxation of the polymer chains in the diffusion process).…”

Magnetic nanoparticles and nanocomposites for remote controlled therapies

“…Iron oxide MNPs were loaded in the reservoir, and when exposed to a static magnetic field of sufficient magnitude, the MNPs aggregated and sealed the pores. In other work, Guilherme et al demonstrated an increase in albumin release rate under exposure to a continuous magnetic field from a superabsorbent hydrogel composite based on vinyl-modified starch, acrylic acid, and N,N-dimethylacrylamide containing iron oxide MNPs [69]. …”