Chitosan chemistry: Relevance to the biomedical sciences

Chitin is well characterized in terms of analytical chemistry, is purified from accompanying compounds, and derivatized in a variety of fashions. its biochemical significance when applied to human tissues for a number of purposes such as immunostimulation, drug delivery, wound healing, and blood coagulation is currently appreciated in the context of biocompatibility and biodegradability. Physical forms (nanoparticles, nanofibrils, microspheres, composite gels, fibers, films) are as important as the chemical structures. Besides being safe to the human body, chitin and chitosan exert many favourable actions, and some chitin based products such as cosmetics, nutraceuticals, bandages, and textiles are presently commercially available. This chapter puts emphasis on the development of new drug carriers and on the interaction of chitosans with living tissues, two major topics of the most recent research activities.