Characterization of chitosan matters


Chitosan is a polysaccharide of N-acetyl-glucosamine and glucosamine units derived largely from invertebrate sources such as shells of shrimp, crab, and fungal cell walls. Chitosan is generally accepted as being biocompatible and biodegradable, and its properties such mechanical strength and degradation can be adjusted by manipulating the relative proportion glucosamine units (i.e., degree of deacetylation, DDA) and its molecular weight (MW). This makes chitosan a highly flexible polymer for meeting requirements in a wide range drug delivery, wound healing, and tissue engineering/regenerative medicine applications. Thus chitosan is not a single polymer but a wide and diverse family of polymers based predominantly on DDA and MW. Because of the difficulty in controlling factors such as original natural sources (e.g., crab, shrimp, fungi) and processing conditions there is highly variable and confusing data on chitosan physical and biological property relationships. This chapter provides an overview on how DDA and MW characteristics of chitosan influence physical and biological properties, and how contaminants such as residual ash (e.g., mineral from shellfish shells) and protein may affect properties and confound results. This chapter emphasizes the importance of determining and reporting DDA, MW, and other contaminants of chitosan materials to be able to reproduce and validate study results and to enable effective development and translation of clinically viable chitosan-based implant devices. Protocols for determining residual ash and protein contents and endotoxin levels are also included.

Publication Title

Chitosan Based Biomaterials