Novel hydrogels of chitosan and poly(vinyl alcohol)-g-glycolic acid copolymer with enhanced rheological properties

Modification of chitosan with monomethyl fumaric acid in an ionic liquid solution

“…Recently, DOSY has been proved to be a useful and handy tool for analysis for a variety of complex mixtures (Balayssac et al, 2009;Han et al, 2012;Primikyri et al, 2012;) and aggregates (Hamdoun et al, 2014;Kotzé, Gerber, Wu, & Koch, 2013;Li, Sun, et al, 2008;Li, Keresztes, Hopson, & Williard, 2009) as well as for the study of the hydrogen bonds between chitosan and poly(vinyl alcohol) (Lejardi et al, 2014). It can resolve diffusion data for each component and permits a fingerprint of complex mixture to be obtained quickly.…”

A vegetable oil-based organogel for use in pH-mediated drug delivery

“…Ideal gels behave as viscous flowing liquids over long time scales and so the storage modulus (G´) must dominate the loss modulus (G´´) in order for the system to be qualified as a gel. 40 Initially, the linear viscoelastic region ) (Fig. 3a).…”

Injectable chitosan/dextran-polylactide/glycerophosphate hydrogels and their biodegradation

“…It can be observed that the chitosan/Dex-PLA/GP(IV) showed its G′ much higher compared to the chitosan/GP. Some reported results for the chitosan/GP gel or other chitosan-based gels point out that the higher density in these gels can result in significantly larger G′ due to increasing intermolecular interactions during the gel formation [11,44,48]. In the present instance, addition of Dex-PLA into the chitosan/GP system with various Dex-PLA amounts would increase the density of chitosan/Dex-PLA/GP gels because the full volume for all gels was a constant value, as shown in Table 2.…”

“…In general, the magnitude of G′ together with the ratio of G′ to G″ can be used to estimate the strength of hydrogels [48,49]. In principle, mechanically strong hydrogels are associated with high G′ values, and meanwhile, G′ of strong hydrogels is usually one order or even two orders of magnitude greater than their G″ [37,44,50].…”

“…Frequency-dependence of G′ and G″ is commonly used to assess rheological properties of hydrogels [37,[44][45][46]. Approximate independence of G′ and G″ against frequency within a relatively low frequency range is considered to be important for evaluating the strength of hydrogels [37,47,48]. Fig.…”