Construction and In Vitro Evaluation of Brain-Targeted Lutein Liposomes

Lutein is one of carotenoids in the human brain that is consistently associated with all cognitive performance indicators, and its levels are closely linked to age-related cognitive decline. However, lutein application is limited by its poor stability and low bioaccessibility. In this study, a lutein-loaded delivery system was developed to enhance stability and achieve brain-targeting effects. Using high-speed shear and ethanol hydration methods, PEGylated lutein liposomes with lactoferrin (Lf-LLips) were constructed and characterized. The morphology was observed using TEM and AFM. Particle sizes and lutein retention rates were evaluated under different temperatures (4 °C, 25 ± 2 °C, 50 °C), light (diffusion light, DL; light shielding, LS), and storage durations at 28 d. Compared with free lutein, the in vitro release behavior and permeability across the blood-brain barrier of the systems were investigated. Lf-LLips exhibited a particle size of 186.63 ± 2.04 nm and a potential of -30.53 ± 1.65 mV, and the lutein encapsulation efficiency was 83.11 ± 1.67%. When stored under LS, the particle size of Lf-LLips remained under 190 nm at 4 °C for 28 days, and the retention rate of lutein exceeded 80%. The release curve of Lf-LLips in vitro over 72 h followed the Weibull model. Furthermore, the permeability across the blood-brain barrier model within 12 h was 22.73 ± 1.42%. These results demonstrate that Lf-LLips significantly improve the stability of lutein and exhibit sustained-release properties along with brain-targeting efficiency. The findings demonstrate the promising future of lutein for applications in brain health enhancement.