Protein and peptide delivery by chitosan systems

Abstract

Chitin is the most abundant amino-polysaccharide polymer found in nature. Chitosan is the main derivative of chitin, which is obtained from the alkaline deacetylation of chitin. Because chitosan has some limitations, chitosan derivatives (i.e., trimethyl chitosan and thiolated chitosan) are successfully employed to develop delivery systems for the administration of proteins. These polymers have mucoadhesive characteristics and penetration potential, so they have been effectively used to deliver proteins. Peptides or proteins as therapeutics are structurally and chemically labile substances. Parenteral is the preferred route for administering proteins and peptides. Besides parenteral route, other routes such as the oral, nasal, and pulmonary routes are also attracting the researchers for the administration of these biotherapeutics. Peptide and protein containing chitosan-based delivery systems improve cellular uptake and absorption across the mucosal sites. Because of their mucoadhesive nature, chitosan and its derivatives have the potential to open tight junctions between epithelial cells, resulting in enhanced penetration. Different chitosan-based delivery systems such as microparticles, nanoparticles, liposomes, and niosomes have been extensively used to deliver proteins. This chapter provides an overview of chitosan-based polymers for the preparation of therapeutic peptides and proteins. The physicochemical characteristics of these different carrier systems as well as their applications in protein and peptide administration through parenteral and other types of administration are discussed