Permeation of flavonoid loaded human serum albumin nanoparticles across model membrane bilayers

The rapid growth in the applications of nanoparticles (NPs) in biomedical and pharmaceutical fields requires an understanding of the interactions with the lipid bilayer membrane for further in vivo studies. Zwitterionic 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), negatively charged 1,2-dioleoyl-sn-glycero-3-phospho-L-serine (DOPS) and positively charged 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) have been used to prepare model lipid membranes and the ability of flavonoid loaded nanoparticles to cross the membranes investigated. The lipid vesicles have been prepared by a freeze-thaw method followed by an extrusion technique and characterised by dynamic light scattering (DLS) and high-resolution transmission electron microscopy (HRTEM). The synthesized model lipid membranes exhibited a bilayer spherical type of morphology with an average diameter of less than 150 nm. A calcein leakage assay and fluorescence anisotropy measurement indicated that the membranes are permeable to the flavonoid (fisetin/morin/epicatechin) loaded human serum albumin nanoparticles. This implies that drug/compound encapsulated nanoparticles are able to effectively cross the lipid bilayer thus permitting the design and development of new compounds that may be encapsulated for safe and potential use in biomedical applications.