Chitin and chitosan polymers: Chemistry, solubility and fiber formation

Chitin and chitosan (CS) are biopolymers having immense structural possibilities for chemical and mechanical modifications to generate novel properties, functions and applications especially in biomedical area. Despite its huge availability, the utilization of chitin has been restricted by its intractability and insolubility. The fact that chitin is as an effective material for sutures essentially because of its biocompatibility, biodegradability and non-toxicity together with its antimicrobial activity and low immunogenicity, points to immense potential for future development. This review discusses the various attempts reported on solving this problem from the point of view of the chemistry and the structure of these polymers highlighting the drawbacks and advantages of each method and proposes that based on considerations of structure-property relations, it is possible to obtain chitin fibers with improved strength by making use of their nanostructures and/or mesophase properties of chitin.