Chitosan-Based Hydrogels: Preparation, Properties, and Applications

Chitosan is a hydrophilic polysaccharide obtained by partial deacetylation of chitin, which is one of the most popular biopolymers. Chitosan is well known for its favorable properties including biocompatibility, biodegradability, antibacterial, and biological activity, as well as its renewable character. Thanks to those features chitosan's popularity in various applications ranging from food industry to tissue engineering is constantly growing. The following chapter will more closely consider fabrication, properties, and specific applications of chitosan-based hydrogel networks. Methods for chitosan preparation will be summarized, followed by detailed characterization of chitosan properties. Strategies for their improvement and fabrication of chitosan derivatives will be discussed as well. Next, attention will be drawn to preparation of chitosan-based hydrogels via chitosan crosslinking. Both chemical and physical crosslinking methods will be considered with special emphasis on comparison between the two crosslinking methods and recent advancements in application of novel biocompatible crosslinkers. This chapter will also take a closer look at formation of stimuli-responsive (especially pH- and temperature-sensitive systems) and injectable hydrogels. Utilization of chitosan hydrogels in tissue engineering will be highlighted together with different techniques for fabrication and construction of three-dimensional scaffolds. Finally, other applications of chitosan-based hydrogels and their composites will be summarized.