Characterization of hydrogels using nuclear magnetic resonance spectroscopy

Characterization of the pore structure of aqueous three-dimensional polyacrylamide gels with a novel cross-linker

“…Most techniques used to investigate the porosity of hydrogels are limited because they require the pore solvent and/or temperature to be altered, causing the gel to shrink, swell or require mathematical manipulation and assumption, which may introduce unwanted artifacts [12,14]. Currently there is no direct method available to analyze and correlate the formation of the three-dimensional polymer network to the properties of the gel.…”

A Convenient Low-Resolution NMR Method for the Determination of the Molecular Weight of Soybean Oil-Based Polymers

“…The literature is full of recent methods 21 where highresolution NMR techniques have been developed for determination of the MW of glassy polymers, polysaccharides, 22 fluoropolyethers, 23 hydrogels, 24,25 and other complex hydrocarbon systems. Although these methods are of considerable interest, they require an even more expensive instrument than gel permeation chromatography.…”

Nano-Engineering of Complex Systems: Smart Nanocarriers for Biomedical Applications

“…To answer this question it is necessary to consider some facts: a) new research has shown that folic acid specific ligand is over expressed in cancer cells and can be also referred to as a tumor marker. Also, as already mentioned in this work that the folate receptor is one of the 25 receptors that mediate the endocytosis process mediated by receptors (Mathur & Scranton, 1996) (previously described), b) the pH inside the tumor cell has a decrease to a value of 4.5 (Katime et al, 2009) and c) the average body temperature is near 36°C . Focusing on these facts we can say that the design of a nanostructure that can be used to treat diseases like cancer must submit specificity, sensitivity to pH and temperature.…”

“…Devices for controlled release of drugs are an especially important application that exploits the collapse-swelling properties of the polymers in response. In this field are particularly important hydrogels containing poly (N-isopropyl acrylamide) (PNIPA), which generate matrices that can exhibit thermally reversible collapse above the LCST of the homopolymer is taken as base (Mathur & Scranton, 1996). The collapse in the structure of the matrix is accompanied by loss of water and any cosolute, as it may be a therapeutic agent or active ingredient.…”