Chitosan-Based Systems for Gene Delivery

Conventional methods for gene delivery with non-viral or viral delivery carriers are beset with various disadvantages such as immune reactions, low transfection efficiency, and toxicity. Innumerable methods are under investigation to help improve the development of biodegradable polymers with low cytotoxicity, transcellular transport ability, favorable physicochemical properties, ease of modification by targeting ligands, and high transfection efficiency. Chitosan is a biodegradable polymer that has attained a lot of attention as a gene delivery vector due to its ease of modification, high transfection efficiency, and exceptional biocompatibility. Chitosan being cationic in nature can form polyelectrolyte complexes with negatively charged DNA allowing nucleic acid condensation along with protection from nucleases, which is widely beneficial in gene therapies. Moreover, factors such as pH, degree of acetylation, N/P ratio, and surface modifications can be suitably investigated to improve transfection efficiency of chitosan-based vectors. Various chitosan-based gene delivery systems developed in the past decade including chitosan-based polyplexes, nanoparticles, and DNA vaccines have been discussed in this chapter. The goal of this book chapter is to review recent advancements in gene therapy with major focus on chitosan and its applications as a gene delivery vector.