AN OVERVIEW ON VARIOUS MODIFICATIONS OF CHITOSAN AND IT’S APPLICATIONS

Chitosan is a natural polysaccharide which is widely exploited for its various applications. It has received much attention as a functional biopolymer especially in pharmaceutics and medicine because of its better biodegradability, biocompatibility, versatility and availability. The unique biological applications of chitosan are attributed to these specific properties. The chemical and biological modification of chitosan is mainly done to increase its solubility in aqueous solutions and absorbability in the in vivo system. A variety of chemical modifications are employed to modify this carbohydrate polymer. The modifications of chitosan are influenced by several factors such as molecular weight of chitosan, viscosity, reaction conditions etc. The selective biological applications include antimicrobial, hypocholesterolemic, antitumor, anti-inflammatory, antioxidant, angiotensin-I-converting enzyme (ACE) inhibition, excluding toxins from the intestines, reducing heavy-metal poisoning in humans, mucoadhesive haemostatic, analgesic, radio-protective properties, preventing tooth decay and tooth diseases and immunity enhancing activities. It is also widely useful in biomedical industries and food industries. The present paper reviews the current trend of investigation on various useful modifications on chitosan and their applications in various fields.