Production, physico-chemical characterization and biodistribution studies of lipid nanoparticles

This study describes the preparation, characterization, in vitro uptake and in vivo biodistribution in mice of solid lipid nanoparticles and nanostructured lipid carriers. The effect of nanoparticle lipid matrix, presence of fluorescent and functionalization by polysorbate 80 on dimensional distribution and morphology have been studied by sedimentation field flow fractionation, photon correlation spectroscopy and cryogenic transmission electron microscopy. The complementary use of different techniques demonstrated that lipid matrix composition, presence of fluorescent dye and polysorbate 80 functionalization have little effect on nanoparticle morphology and size distribution. Uptake of fluorescent nanoparticles was determined in vitro by human brain endothelial cells, showing that nanoparticles treated by polysorbate 80 displayed lower uptake values with respect to the corresponding control nanoparticles. Biodistribution of solid lipid nanoparticles treated by polysorbate 80 was evaluated by fluorescent luminescent imaging after intraperitoneal administration in mice. The in vivo images indicate that SLNs treated with polysorbate 80 four hours after i.p. administration were able to reach the brain even if they accumulated prevalently in the anatomical areas corresponding to liver and spleen.