Structural and spectroscopic features of lutein/butanoyl-beta-cyclodextrin nanoassemblies

Lutein, the primary carotenoid present in the central area of the retina of eye appears to be associated with the protection against age-related macular degeneration (the leading cause of blindness in older adults). Its lipophilicity and consequently its scarce water solubility (1.3 × 10−9 M) represent a drawback for bioavailability. To circumvent these unfavorable characteristics, in this work lutein (Lut) have been encapsulated in amphiphilic cyclodextrin (ACyD) by following the well-established strategy of entrapping a lipophilic drug in CyD carriers. Primary face butyrate modified β-cyclodextrins (C4:7) form in water nanoaggregates with a average size of 250 nm and a ζ-potential of about −6 mV. They are able to entrap lutein at 1:6 Lut/ACyD molar ratio by yielding nanoassemblies of vesicular aspect (320 nm and −8 mV) such as observed by static, dynamic and electrophoretic light-scattering. UV–vis measurements revealed that electronic properties of lutein were maintained when interact with ACyD nanoaggregates. The monitoring of the entapped carotenoid leaking from ACyD nanostructures was investigated suggesting the potential of Lut/ACyD nanoassemblies in drug delivery.