Liposomes Containing Esters of the Natural Antioxidant Astaxanthin Modified with Pluronic F68 or DSPE-PEG 2000

Abstract

Liposomes containing a natural antioxidant, astaxanthin esters, are prepared by dispersing the lipid film and evaporating from chloroform with further ultrasonic treatment. To increase the stability of the astaxanthin esters, liposomes based on Lipoid S75 (2 mg/mL) are modified with pluronic F68 or PEGylated distearylphosphatidylethanolamine (DSPE-PEG 2000). As a result of optimization, the ratio of phospholipid and modifiers is selected for stable liposomes with 0.5 mg/mL astaxanthin esters. Liposomes with 0.5% pluronic F68 consists of two fractions with sizes of 110 ± 15 and 440 ± 15 nm, and liposomes with DSPE-PEG 2000 (2.5 mg/mL) have one fraction with an average hydrodynamic diameter of 255 ± 40 nm. The ζ potentials of the liposomes are –35 ± 15 and –60 ± 10 mV, respectively. When mononuclear blood cells are incubated with the developed liposomes for 24 h, the survival rate is found to be 84 ± 4%. It is shown that liposomes with astaxanthin esters of different compositions inactivate the ABTS cation radical 17–50% more effectively than liposomes without astaxanthin esters.