Design and application of chitosan microspheres as oral and nasal vaccine carriers: an updated review

Abstract

Chitosan, a natural biodegradable polymer, is of great interest in biomedical research due to its excellent properties including bioavailability, nontoxicity, high charge density, and mucoadhesivity, which creates immense potential for various pharmaceutical applications. It has gelling properties when it interacts with counterions such as sulfates or polyphosphates and when it crosslinks with glutaraldehyde. This characteristic facilitates its usefulness in the coating or entrapment of biochemicals, drugs, antigenic molecules as a vaccine candidate, and microorganisms. Therefore, chitosan together with the advance of nanotechnology can be effectively applied as a carrier system for vaccine delivery. In fact, chitosan microspheres have been studied as a promising carrier system for mucosal vaccination, especially via the oral and nasal route to induce enhanced immune responses. Moreover, the thiolated form of chitosan is of considerable interest due to its improved mucoadhesivity, permeability, stability, and controlled/extended release profile. This review describes the various methods used to design and synthesize chitosan microspheres and recent updates on their potential applications for oral and nasal delivery of vaccines. The potential use of thiolated chitosan microspheres as next-generation mucosal vaccine carriers is also discussed.

Biomaterials for Nanoparticle Vaccine Delivery Systems

“…Chitosan has attractive properties for vaccine delivery applications, including high availability, biodegradability, and biocompatibility. In addition, high density of amino groups in chitosan allows facile chemical modification, complexation with negatively charged antigens, and muco-adhesiveness (59,60). Chitosan has been formulated into nano/microparticles without the use of organic solvents or high shear stress via ionotropic gelation and self-assembly of polyelectrolytes, preserving immunogenicity of antigens (61,62).…”

Efficient delivery of recombinant human bone morphogenetic protein (rhBMP‑2) with dextran sulfate‑chitosan microspheres

“…In searching for such delivery system, it is noticed that chitosan (CS), a cationic polysaccharide, has been widely used as a drug carrier due to its good biocompatibility and biodegradability and CS-based microsphere have shown some distinct advantages in delivery of various bio-active species ( 24 ). It has been demonstrated that CS-based microspheres as a drug delivery system (DDS) is able to reduce side effects, improve drug stability and enhance therapeutic efficacy of drugs and proteins ( 25 , 26 ).…”

Astragalus Polysaccharides/Chitosan Microspheres for Nasal Delivery: Preparation, Optimization, Characterization, and Pharmacodynamics

“…The chitosan (CTS) microsphere is a potential drug carrier and enhances absorption by opening tight junctions between the epithelial cells (Abdel Mouez et al, 2014). The CTS microsphere has been used as a promising carrier system for both vaccines and DNA (Islam et al, 2012).…”