Wheat germ agglutinin-grafted lipid nanoparticles: preparation and in vitro evaluation of the association with Caco-2 monolayers.

A bioadhesive drug delivery system, wheat germ agglutinin (WGA)-grafted lipid nanoparticles, was developed for the oral delivery of bufalin (a hydrophobic active component extracted from the traditional Chinese medicine Chan'su). The lipid nanoparticles associated with poly(vinyl alcohol) (PVA) were prepared by high-pressure homogenization. WGA was coupled to lipid nanoparticles by activating the hydroxyl group using glutaraldehyde, and then conjugating the nanoparticles with WGA. WGA-grafted lipid nanoparticles with a mean particle size of 164 nm and zeta potential of -10.6 mV were obtained with bufalin encapsulation of 68.2%. The amount of bound WGA was approximately 28.9% of the amount of WGA initially added. The association study between fluorescent 6-coumarin-loaded WGA-grafted lipid nanoparticles and Caco-2 monolayers showed that WGA enhanced the cellular uptake of nanoparticles compared with WGA-free lipid nanoparticles. These results suggest that WGA-grafted lipid nanoparticles could be a promising carrier to enhance cellular uptake. They could also improve drug bioavailability through the oral route.