Preparation and characterization of astaxanthin-loaded liposomes by phytosterol oleate instead of cholesterol

Hydrophobic bioactive compounds like astaxanthin (AST) exhibit poor water solubility and low bioavailability. Liposomes, which serve as nanocarriers, are known for their excellent biocompatibility and minimal immunogenicity. Traditionally, liposomes have been primarily constructed using phospholipids and cholesterol. However, the intake of cholesterol may pose a risk to human health. Phytosterol ester was reported to reduce level of cholesterol and improve properties of liposomes. In this study, phytosterol oleate was used to prepare liposomes instead of cholesterol to deliver AST (AST-P-Lip). The size range of AST-P-Lip was 100–220 nm, and the morphology was complete and uniform. In vitro studies showed that AST-P-Lip significantly enhanced the antioxidant activity and oral bioavailability of AST. During simulated digestion, AST-P-Lip protected AST from damage by gastric and intestinal digestive fluid. Additionally, AST-P-Lip had a good storage stability and safety. These results provide references for the preparation of novel liposomes and the delivery of bioactive compounds.