s Chitosan Nanoparticles Plus KLH Adjuvant as an Alternative for Human Dendritic Cell Differentiation

Background: Immunotherapy involving dendritic cells (DC) has been used to treat cancer with satisfactory results. The generation of mature dendritic cells derived from monocytes, however, is expensive because of the use of cytokines. Objective: To reduce DC therapy costs, it is important to evaluate lower-cost materials capable of inducing dendritic cell maturation; for this purpose, we synthetized chitosan nanoparticles. Methods: Chitosan nanoparticles were synthetized by ionic gelation and characterized using dynamic light scattering, laser Doppler electrophoresis, transmission electron microscopy and infrared spectrum. Endotoxin levels were determined by Limulus amoebocyte lysate. The biological effect was evaluated by microscopy, immunophenotypification, cellular viability and phagocytosis assays. Results: We synthetized endotoxin-free chitosan nanoparticles with an average size of 208 nm and semi-spherical morphology. The nanoparticles induced changes in monocyte morphology, surface marker expression and phagocytosis that correlate with those of DC. These preliminary results demonstrate that chitosan nanoparticles can induce monocyte differentiation into immature dendritic cells and, when combined with albumin and keyhole limpet hemocyanin, they can induce dendritic cell maturation. Conclusion: We conclude that chitosan nanoparticles are a suitable alternative for lower-cost DC immunotherapy generation, provided that our results be corroborated in vivo.