Bioactivity of Chitosan and its Derivatives

Background: Regarded as biofunctional poly- and oligomers having much higher potential than cellulose in many fields, chitosan and its derivatives have become of great interest thanks to the recent progress in chitin chemistry. Chitosan, which is a natural-based polymer obtained by alkaline deacetylation of chitin, is an interesting bioactive polysaccharide composed of many reactive groups. Objectives: This gives huge possibilities of chemical modifications to create new derivatives with a broad range of physico-chemical and biological activities. Method and Results: Special emphasis is given here to quaternized, N-alkyl, N-acyl, oxychitosan derivatives but also depolymerized chitosan. The present review also provides insights into chitosan derivatives and their biological activities. Numerous studies led for twenty years until now have put on track antimicrobial and antioxidant activities of chitosan derivatives. Biomedical applications have also been addressed, such as bioadhesive properties, antitumor activities, adsorption or chelation. Recent progresses of chitosan derivatives chemistry opened the way to new developments in medical and pharmaceutical fields, for example in tissue engineering or drug delivery system. Finally, biodegradability and environmental assessment concepts are reported. Conclusion: This work highlights the need for integral and comprehensive approach to comprehend all the biological potential of chitosan and its derivatives.