Chemically modified chitin and chitosan as biomaterials

Recent studies of the chemical modification of chitin and chitosan are discussed from the viewpoint of biomedical applications. Special emphasis is placed on the role of individual functional groups in applications of modified chitosan. The modifications discussed here include chitosan attached to sugars, dendrimers, cyclodextrins, crown ethers, and glass beads. Among these derivatives, sugar-modified chitosans are excellent candidates for drug delivery systems or cell culture owing to their specificity. Chitosan-dendrimer hybrids are interesting multifunctional macromolecules. Chitosan and its derivatives are useful as carriers in drug delivery systems, as antibacterial agents, and in other medical applications. (C) 2004 Elsevier Ltd. All rights reserved.