ZnO-ZnS QDs interfacial heterostructure for drug and food delivery application: enhancement of the binding affinities of flavonoid aglycones to bovine serum albumin.

Zero-dimensional nanostructures are green nanomaterials that have recently attracted increasing attention. However, very little information is available on whether or not these heterostructures affect drug transport in blood. In current work, flavonoid aglycones were studied for their affinities for bovine serum albumin (BSA) in the presence and absence of zinc oxide-zinc sulfide quantum dots (ZnO-ZnS QDs) in vitro. The fluorescence intensity of BSA decreased remarkably with increasing concentration of ZnO-ZnS QDs, resulting in an obvious red-shift of the maximum emission of BSA from 340 to 348 nm. The magnitudes of binding constants in the presence of QDs ranged from 10(4) to 10(6) L/mol, and the number of binding sites per BSA molecule (n) was determined as 1.12 ± 0.17. Although ZnO-ZnS QDs significantly increased the affinities for BSA of myricetin, luteolin, gallocatechin gallate, tectorigenin, and formononetin, they barely affected the binding affinities of flavone, (-)-epicatechin gallate, and quercetin. FROM THE CLINICAL EDITOR: Serum albumins are major transport proteins in blood that reversibly bind fatty acids, amino acids, drugs, and inorganic ions, which interactions have important effects on the distribution, free concentration, and metabolism of drugs in blood. In this research nine flavonoid aglycones were studied for their affinities for bovine serum albumin (BSA). Interestingly it was found that presence of ZnO-ZnS QDs significantly increased the affinities of BSA for several of these aglycones.