Buffers can modulate the effect of sonication on egg lecithin liposomes

Area of Science:

• Biochemistry and Biophysics
• Membrane Science
• Lipid Peroxidation Research

Background:

• Ultrasonic irradiation of polyunsaturated phospholipids in model membranes can generate radicals.
• Radical production leads to degradation of polyunsaturated fatty acyl chains and lipid hydroperoxide formation.
• This process compromises the integrity of liposomes and associated biomolecules.

Purpose of the Study:

• To investigate the protective effects of organic buffers during liposome preparation.
• To compare the efficacy of Hepes and Tris buffers in preventing lipid peroxidation induced by sonication.
• To understand the mechanism of buffer protection based on radical scavenging properties.

Main Methods:

• Model membranes were prepared using ultrasonic irradiation of polyunsaturated phospholipids.
• Hepes and Tris buffers were employed at a 10 mM concentration during sonication.
• Lipid peroxidation levels were assessed after 30 minutes of sonication.

Main Results:

• Both Hepes and Tris buffers demonstrated a protective effect against lipid peroxidation.
• Hepes provided significant protection, achieving 70% reduction in lipid peroxidation.
• Tris offered moderate protection, with a 50% reduction under identical conditions.

Conclusions:

• Organic buffers, particularly Hepes, are effective in mitigating sonication-induced lipid peroxidation.
• The protective efficacy correlates with the rate constants of buffers reacting with hydroxyl radicals.
• These findings are crucial for optimizing liposome preparation protocols to maintain membrane integrity.