Characterization of high density lipoprotein from egg yolk and its ability to form nanocomplexes with chitosan as natural delivery vehicles

In this work, egg yolk high density lipoprotein (HDL) was first extracted and solubilized with a salt-free method. The freshly purified egg yolk HDL was characterized for its physicochemical properties and its delivery potentials for hydrophobic bioactives were also investigated. Native chitosan (NACS) and its amphiphilic derivative (stearic acid conjugated chitosan, SACS) were adopted to fabricate polyelectrolyte nanocomplexes with egg yolk HDL and the fabrication as well as formulation of nanocomplexes were optimized. HDL/SACS and HDL/NACS nanocomplexes had a diameter of 75 nm and 97 nm, respectively. Gastrointestinal stability tests suggested that the nanocomplexes were more stable in gastric phase than in the intestinal condition with the presence of digestive enzymes (pepsin and pancreatin). Curcumin was selected as a model hydrophobic compound to assess the encapsulation and delivery potentials of HDL-based nanocomplexes. HDL/SACS nanocomplexes showed better encapsulation property than HDL/NACS nanocomplexes due to enhanced hydrophobic interactions, which was confirmed by fluorescence and surface hydrophobicity tests. The HDL/SACS nanocomplexes also exhibited slower sustained release of curcumin in simulgated GI tract, indicating the promising features as nanoscale oral delivery vehicles for hydrophobic phytochemicals. (C) 2017 Elsevier Ltd. All rights reserved.