High-molecular-weight chitosan

Chitosan is a biodegradable polysaccharide and has been shown to interact with the phosphate groups of DNA, condensing plasmids into spherical and toroidal particles. The colloidal and surface properties of plasmid/chitosan complexes have been shown to depend on the molecular weight of chitosan, the ratio of plasmid to chitosan and the preparation medium. Smaller nanoparticles have been observed with low molecular weight chitosan (2 kDa) as compared to high molecular weight chitosan (540 kDa). A number of cell lines have been transfected with plasmid/chitosan complexes. 

Clear relationship - Low Mw chitosan 2D chains between - Medium molecular weight chitosan single nanoparticles morphology and - High molecular weight chitosan nanoplates molecular weight... 

To improve the transfection efficiency and cell specificity, Gao et al. [76] depo-lymerized the high molecular weight chitosan (HMWC) into low molecular weight chitosan (LMWC), and then it was modified with galactose group. They... 

On the other hand, literature studies report that the survivability and stability of probiotic bacteria loaded into chitosan-coated alginate microcapsules are largely dependent on the molecular weight of chitosan. ° Thus, the microcapsules prepared with high molecular weight chitosan provided a higher survival rate (46%) compared with the microcapsules made with low molecular weight chitosan (36%). ... 

Incorporation of sodium acetate has been found to drop the viscosity of chitosan solution (Fig. 19.16) [50]. The effect of electrolyte was observed to be more pronounced on high-molecular-weight chitosan, CHT-MC. With decrease in molecular weight of chitosan, the amount of sodium acetate required to attain a minimal viscosity was decreased. The decrease in viscosity with increase in electrolyte concentration can be attributed to the shielding effect... 

Homer V, Pittermann W., Wachter R., Efficiency of high molecular weight chitosan in skin care application, in Adv. Chitin Sci., Eds. Domard A., Roberts G.A.F., and Vamm K.M., Jacques Andre Publisher, Lyon, 1997, Volume II, pp. 671-677. 

Do, J. Y, Kwak, D. M., and Kwon O. D. 2008. Antidiabetic effects of high molecular weight chitosan in streptozotocin-induced type 1 diabetic ICR mice. Laboratory Animal Research 24 311-317. 

This innovative experiment demonstrates that the polyplexes of the oligomer fractions have superior physicochemical properties in comparison to the commonly used high-molecular-weight chitosan. 

Lian, G.M. and Chen, K.C. 1998. Effect of high molecular weight chitosan on nutrient digestibility, blood lipids and fecal contents in rats. In Advances in Chitin Science, Proceedings of the 3rd Asia-Pacific Chitin and Chitosan Symposium, Keelung, Taiwan, pp. 229-306. 

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