UEA I-bearing nanoparticles for brain delivery following intranasal administration

Surface engineering of nanoparticles with lectins opened a novel pathway to improve the brain uptake of agents loaded by biodegradable PEG-PLA nanoparticles following intranasal administration. Ulex europeus agglutinin I (UEA I), specifically binding to l-fucose, which is largely located in the olfactory epithelium, was selected as a promising targeting ligand and conjugated onto the PEG-PLA nanoparticles surface with an optimized protocol relying on maleimide-mediated covalent binding technique. The in vivo results in rats suggested that UEA I modification at the nanoparticles surface facilitated the absorption of a fluorescent marker—6-coumarin associated with the nanoparticles into the brain following intranasal administration with significant increase in the area under the concentration–time curve (about 1.7 times) in different brain tissues compared with that of coumarin incorporated in the unmodified ones. UEA I-conjugation also elevated the brain-targeting efficiency of nanoparticles. Inhibition experiment of specific sugar suggested that the interactions between the nasal mucosa and the lectinised nanoparticles were due to the immobilization of carbohydrate-binding pockets on the surface of the nanoparticles. Distribution profiles of UEA I-modified nanoparticles indicated their higher affinity to the olfactory mucosa than to the respiratory one. Therefore, the UEA I-modified nanoparticles might serve as potential carriers for brain drug delivery, especially for mental therapeutics with multiple biological effects.