Quatemized chitosan

Wu J, Wei W, Wang LY, Su ZG, Ma GH (2007) A thermosensitive hydrogel based on quatemized chitosan and polyethylene glycol) for nasal drug delivery system. Biomaterials 28 2220-2232. 

Thanou M, Florea BI, Geldof M et al (2002) Quatemized chitosan oligomers as novel gene delivery vectors in epithelial cell lines. Biomaterials 23 153-159... 

Quatemized chitosan (QCh) derivatives have a high activity against bacteria and thus are potential candidates for wound dressing applications. Electrospun QCh fiber mats were successfully prepared by electrospinning QCh solutions mixed with PVA [131]. The electrospun QCh/PVA fiber mats were stabilized against dissolution in aqueous environment using photomediated crosslinking. 

The quatemization of the primary amine was investigated [28, 29]. This chemical modification increased the solubility of chitosan in water [30], keeping chitosan soluble over a wide pH range. In addition, the cationic character [23] can be controlled and kept pH-independent, which is desirable for improving the stability of ionic complexes [31, 32]. Typically, the reaction of chitosan with methyl iodide under basic conditions is the most straightforward route for quatemizing chitosan [33]. 

Among all the quatemized chitosans described into literature, W,W,W-trimethyl chitosan chloride (TMC) is the most widely applied for gene therapy applications [28, 33, 34]. The quatemization maintained and improved the muco-adhesive properties of chitosan, depending on the quatemization degree, which makes this chitosan derivative an ideal candidate for gene delivery [23]. Typically, TMC can be synthesized by reaction of chitosan with methyl iodide in the presence of sodium hydroxide into A-methyl-2-pyrrolidinone at 60 °C. In a second step, the iodide ion is substituted by chloride by an ion exchange process [34] (Fig. 2). 

Guo et al. (2006) have synthesized A -substituted chitosan and quatemized chitosan and evaluated their antioxidative activity on hydroxyl radicals. It has been found that the antioxidative activity of quatemized chitosan derivatives was higher than that of TV-substituted chitosan derivatives. 

Uragami, T., Kato, T., Nagayasu, H., and Yura, I. 1993a. Transport of nucleic acid bases against their concentration gradients through quatemized chitosan membrane. Carbohydr. Polym. 21 289-293. 

Uragami, T., Takuno, M., and Miyata, T. 2002a. Evapomeation characteristics of cross-linked quatemized chitosan membranes for the separation of an ethanol/water azeotrope. Macromol Chem. Phys. 203 1162-1170. 

Uragami, T., Tanaka, Y, and Nishida, S. 2002b. Permeation and separation under high temperature and high pressure for ethanol/water vapors through cross-linked quatemized chitosan composite membranes. Desalination 147 449 54. 

Quatemized chitosan (QCS)/poly (aspartic acid) nanoparticles For protein dmg-delivery [187]... 

Quatemized chitosan-organic rectorite intercalated composites based NPs For protein controlled release [189]... 

NPs of quatemized chitosan derivatives As a carrier for colon delivery of insulin Ex vivo and in vivo studies [191]... 

Wang et al., has explored quatemized chitosan (QCS)/poly (aspartic acid) NPs as a most reliable carrier protein dmg-delivery system. Similarly various other examples are below mentioned in tabular form (Table 3.3). 

Wan Y, Peppley B, Creber KAM, Bui VT, Halliop E (2008) Quatemized-chitosan membranes for possible applications in alkaline fuel cells. J Power Sources 185 183-187... 

Ignatova, M., N. Manolova, and I. Rashkov (2007). Novel antibacterial fibers of quatemized chitosan and poly(vinyl pyrrolidone) prepared by electrospinning . European Polymer Journal 43(4) 1112-1122. 

Shu, S., Zhang, X., Wu, Z., Wang, Z., Li, C. Delivery of protein drugs using nanoparticles self-assembled from dextran sulfate and quatemized chitosan. J. Controlled Release 152, el70-el72(2011)... 

R. Belalia, S. Grelier, M. Benaissa, V. Coma, New bioactive biomaterials based on quatemized chitosan, J. Agric. Food Chem. 56 (2008) 1582-1588. 

Fig. 6 Quatemized chitosan derivatives TMC trimethylchitosan, HTCC Af-hydroxypropyltri-methylammoniumchitosan...

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