ABSTRACT
Chitosan is a second abundant heteropolysaccharide composed of β-(1-4)-2-deoxy-2-amino and -2-acetamino D-glucopyranose units [31]. Chitosan is the partial deacetylated (involving alkaline hydrolysis) product of chitin. Chitin is the main component of outer skeleton of small insects, cuticles, and the shells of shrimp, crab, lobster, etc. Chitosan has been expansively investigated in the pharmaceutical industries for the development of various sustained and controlled release drug delivery systems due to its versatile biological activity (as food and non-food items) and excellent biocompatibility. Hirano [22] conducted an experiment with both healthy and infected skin and found the LD50 in case of orally administered mouse to be (>16 g/kg). Wu et al. [76] worked on
acylated chitosan derivatives and reported their ability to increase membrane permeability in vitro and in vivo. It is a safe and friendly substance for humans; therefore, medical and pharmaceutical applications can be easily worked out with joint efforts from specialist in various ields [57]. Biodegradability of chitosan is of paramount importance because it is easily degraded by ubiquitous enzymes in the human body, and the oligomers so formed can activate macrophages too.
