Water-soluble chitosan

Patent RF Xe 2215749, The method of preparation of chitosan water-soluble forms. 

Chitosan Water-Soluble System An Approach to Prepare Superabsorbent Gel... 

Imidazole acetic acid (lAA) was introduced to [63-65] chitosan. Water-solubility was also improved by introduction of lAA to chitosan... 

The Jordi polyethyleneimine phase has been developed in an attempt to block adsorptive effects of the PDVB surfaces toward cationic polymers such as chitosan and quaternary water-soluble flocculants (Fig. 13.17). 

A novel fiber-reactive chitosan derivative was synthesized in two steps from a chitosan of low molecular weight and low degree of acetylation. First, a water-soluble chitosan derivative, N-[(2-hydroxy-3-trimethylammonium)-... 

Another polysaccharide system that has received considerable interest is the chitosans which are water soluble derivatives of chitin. These materials appear to be very biocompatible and degradable and so are potentially excellent candidates as polymeric drug systems (27). 

Ren H, Endo H and Hayashi T (2001a), Antioxidative and antimutagenic activities and polyphenol content of pesticide-free and organically cultivated green vegetables using water-soluble chitosan as a soil modifier and leaf surface spray , JSci FoodAgric, 81, 1426-1432. 

Similar structures were later employed to create original dendronized polymers 485 and 486, based on a chitosan backbone and using such sialodendrons as 484 (Fig. 50).328 Chitosan itself is nontoxic, biodegradable, and has widespread biological activities, but major intrinsic drawbacks such as low solubility in both organic solvents and water have hampered its development as a bioactive polymer. Thus, the synthesis of water-soluble... 

We initially prepared the first chitosan-sialoside hybrid 19 by treating 80% de-AT-acetylated chitosan with p-formylphenyl a-sialoside 6 (Scheme 1) under reductive amination conditions (NaBH3CN) (Scheme 7) [64]. The level of sialo-side incorporation could be controlled by increasing the amount of 6 (Table 15.2). The reactivity of aldehyde 6 toward chitosan was found to be in the range 25-48% due to excessive reduction of the aldehyde under the acidic reaction conditions. Water-soluble materials were only achieved at high DS (DS > 0.53). Sialo-hybrids with lower substitutions were further derivatized with succinic... 

Gold nanoparticles can also be stabilized using polymers that do not have specific functional groups through physisorption. Among the possible stabilizers, the polymers used most often to stabilize Au NPs are the water soluble polymers poly(N-vinylpyrrolidone) (PVP), polyethylene glycol) (PEG), poly(vinyl pyridine), poly(vinyl alcohol) (PVA), poly(vinyl methyl ether) (PVME), and polyelectrolytes such as PAA, chitosan, polyethyleneimine (PEI) or poly(diallyl dimethylammonium) chloride (PDDA) [99]. 

Chitosan is a polymer produced from hydrolysis of natural chitin. Chitosan is not readily soluble in aqueous solutions, but can be solubilized and is thus considered with other water soluble polymers. In the hydrophobic form, chitosan has been treated in a similar manner to other hydrophobic polymers with microparticles produced by emulsion and phase separation techniques. Microparticles can be taken up by the gastrointestinal lining in a manner similar to that discussed for other hydrophobic microparticles. 

In vivo studies were also conducted by several researchers. Anraku et al. (2009) examined the antioxidant effects of water-soluble chitosan in normal subjects by measuring the reduction of indices of oxidative stress. Treatment with chitosan for 4weeks produced a significant decrease in levels of plasma glucose and the atherogenic index, and led to an increase in high-density lipoprotein cholesterol (HDL-C). Chitosan treatment also lowered the ratio of oxidized to reduced albumin and increased total plasma antioxidant activity. Further, Anraku et al. (2011) proved the antioxidant effects of high MW chitosan in normal volunteers, and the obtained results were consistent with previous results observed by Anraku et al. (2009). 

Anraku, M., Fujii, T., Furutani, N., Kadowaki, D., Maruyama, T., Otagiri, M., Gebidki, J. M., and Tomida, H. (2009). Antioxidant effects of a dietary supplement Reduction of indices of oxidative stress in normal subjects by water-soluble chitosan. Food Chem. Toxicol. 47, 104-109. 

Portero A, Remunanlopez C, Vilajato JL. Effects of chitosan and chitosan glutamate enhancing the dissolution properties of the poorly water soluble drug nifedipine. Int J Pharm 1998 175 75-84. 

Onishi, H., and Y. Machida. 1999. Biodegradation and distribution of water-soluble chitosan in mice. Biomaterials 20 175. 

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