Chapter 2 - Synthesis of chitosan-based nanomaterials

Abstract

Chitosan nanoparticles (NPs) are widely studied as a carrier for drug, protein, and gene delivery. However, lack of sufficient stability, particularly under physiological conditions, renders chitosan NPs of limited pharmaceutical utility. Chitosan-based nanoparticles have a long-range of applications in antifungal (like Alternaria alternata, Macrophomina phaseolina and Rhizoctonia solani) and antimicrobial (like A. alternata, M. phaseolina and R. solani.) applications too. Chitosan has been utilized for not only the formation of metallic nanoparticles but also novel biodegradable nanoparticles based on chitosan for biomedical applications. For the synthesis of these biodegradable nanoparticles, chitosan is crosslinked by using a different cross-linking agent and varying medium environment (pH range varying from acidic to alkali). Some of the important crosslinking agents used for making chitosan-based nanoparticles (like polycations, polyanions, and polyampholyte nanoparticles) are di- and tricarboxylic acids. Chitosan can react with crosslinking agents for in situ chemical crosslinking due to the abundance of hydroxyl (-OH) and amine (-NH2) groups. Chitosan NPs can be synthesized using a “bottom-up” or “top-down” approach and/or a combination of the two procedures. Chitosan can be cross-linked with glutaraldehyde, glyoxal, and terephaldehyde to form hydrogels. Chitosan has a benefit for a great length of derivatives that can be synthesized from Chitosan because of the presence of the amino group in conjunction with the alcohol group, which gives rise to N-modified Chitosan, O-modified Chitosan, or N, O-modified chitosan. This chapter overview the state of the art regarding different methods of synthesis and characterization of Chitosan-based nanoparticles, improvement in antifungal and antimicrobial activity of chitosan-based nanoparticles, Biomedical application: wound healing activity, nanosystem against cancer treatment, chitosan NPs in drug delivery, gene delivery, and transfection, toxicity determination, and future work.