Preliminary characterization of N-trimethylchitosan as a nanocarrier for malaria vaccine.

ABSTRACT

Background & objectives: With the current snags from the use of Artemisinin-combination therapies (ACTs) in malaria treatment in addition to fear of cross-resistance to unrelated drugs, raising the immunocompetence of individuals in malaria endemic areas by vaccination is the best approach to malaria-free world. Methods: Water-soluble cationic derivative, N, N, N-trimethylchitosan (TMC) was synthesized from chitosan. Nanoparticles of the TMC were prepared in various media [milliQ water, Na2CO3 (pH 10.92), Na2HPO4 (PBS, pH 9.01 and alhydrogel®] which were characterized as adjuvants for possible vaccine delivery. The nanoparticles were characterized for particle size, surface charge and morphology using microscopy (Phase contrast microscope and Confocal laser scanning microscope), and Malvern zetasizer Nano-ZS. Time-resolved particle size analysis was performed after one month storage of the TMC nanoparticles at 4°C. Results: The result of the study showed that PBS was the best medium that produced cationic, monodispersed and stable TMC nanoparticles of <65 nm forming a compatibly homogeneous system even upon storage. Details of the polyelectrolyte-doped nanoparticles in PBS showed clear coatings due to Sodium poly (styrene sulfonate) [PSS, MW ~70 kDa] at the periphery of the particles and a fluorescent core with some tiny central hollow cavities implying that the nanoparticles can either entrap the vaccine candidate into the hollow cavities or adsorb them unto the surface of the peripheral polyelectrolyte coatings. Interpretation & conclusion: This preliminary study established that TMC has the desired qualities for the intending antigen delivery. Further research regarding the biological activity of this TMC is indicated.