Full factorial design, physicochemical characterisation and biological assessment of cyclosporine A loaded cationic nanoparticles.

Cyclosporine A loaded poly(lactide-co-glycolide) nanoparticles coated with chitosan were prepared using the o/w emulsification solvent evaporation method. A 2(3) full factorial design was used to investigate the effect of 3 preparation parameters on the particle size, polydispersity index, zeta potential and drug release. In vitro experiments were performed in order to evaluate the cytotoxicity and anti-inflammatory activity of the developed nanoparticles. Particle sizes varied from 156 nm to 314 nm, and polydispersity index values of 0.07-0.56 were obtained depending on the different preparation parameters. All nanoparticles showed positive zeta potential values. Nanoparticles prepared with the highest concentration chitosan retained a positive zeta potential after dispersion in simulated lachrymal fluid, which supports the possibility of an electrostatic interaction between these particles and the negatively charged mucus layer at the eye. The in vitro release profile of cyclosporine A from the chitosan-coated nanoparticles was strongly dependent on the release medium used. None of the cationic nanoparticle formulations showed significant cytotoxicity compared to the negative control using human epithelial cells (HaCaT). Cyclosporine A encapsulated in the various nanoparticle formulations remained anti-inflammatory active as significant suppression of interleukine-2 secretion in concanavalin A stimulated Jurkat T cells was observed.