Improvements of Solubility and Bioavailability of Lutein Through Grafting with Hydrophilic Polyacrylic Acid.

In this study, polyacrylic acid grafted lutein (PAA-g-lutein) was prepared by hydrophilic modification of lutein with polyacrylic acid (PAA) through Steglish esterification method. The unreacted lutein was loaded in micelles formed by self-assembly of graft copolymers in water to form composite nanoparticles. The bioaccessibility and bioavailability of lutein nanoparticles were studied by in vitro and in vivo digestion experiments. Compared with free lutein, the saturated solubility and bioaccessibility of lutein nanoparticles were increased by 78 times and 3.6 times, respectively. The pharmacokinetics results in the mice model showed that the maximum concentration (C max) and area under concentration-time curve (AUC) of plasma of mice were increased by 3.05 and 6.07 times with lutein nanoparticles compared with free lutein. Meanwhile, the prepared lutein nanoparticles also promoted the accumulation of lutein in the liver, mesenteric adipose, and eyeballs. These results indicate that graft copolymerization of lutein with water-soluble polymers to form nanoparticles is an effective method to promote the bioavailability of lutein in vivo. Moreover, this method is simple and applicable, and can also be used for the modification of other bioactive molecules. [Display omitted] • The graft copolymer was synthesized by hydrophilic modification of lutein with polyacrylic acid by esterification reaction. • Nanocomposite particles were prepared by graft copolymer loaded lutein for self-assembly. • In vitro simulated digestion experiments indicated that lutein nanoparticles promoted the saturation solubility and bioaccessibility of lutein. • The pharmacokinetics results in the mice model proved that the modification improved the bioavailability of lutein and sustained release. [ABSTRACT FROM AUTHOR]