Polypeptide – decorated nanoliposomes as novel delivery systems for lutein

Lutein (LUT) is a bioactive food compound found in various vegetables and plays a critical role in the promotion of health and well-being. However, lutein is an unstable molecule which has a very low bioavailability caused by its poor solubility in aqueous media, and is poorly absorbed when administered orally. To enhance the stability, release and bioactivity of lutein, poly-l-lysine (PLL) decorated nanoliposomes (PLL–LUT-NLP) were developed as novel delivery systems for lutein. The mean particle size of PLL–LUT-NLP was found to be in the range 264–367 nm with a low polydispersity index (PDI < 0.4). The zeta potential changed from −38.6 mV in undecorated nanoliposomes to −27.9 mV in PLL-decorated nanoliposomes. Furthermore, the lutein entrapment efficiency (EE%) of PLL–LUT-NLP was found to be highest in nanoliposomes decorated with 0.06% (w/v) PLL. PLL could protect lutein in nanoliposomes from degradation and promote the lutein release from the nanoliposomes in gastrointestinal fluid conditions. Additionally, the PLL-decorated nanoliposomes maintained the antioxidant activity of the lutein, and the antiproliferative activity was more significant than that of undecorated nanoliposomes in inhibiting the proliferation of human tumor cells. These results suggest that PLL-decorated nanoliposomes have potential to be used for efficient delivery of lutein and further improve its bioavailability.