Influence of cholesterol on electroporation in lipid membranes of giant vesicles

• Published in: European biophysics journal Vol. 49; no. 5; pp. 361 - 370
• Main Authors: Karal, Mohammad Abu Sayem, Ahamed, Md. Kabir, Mokta, Nadia Akter, Ahmed, Marzuk, Ahammed, Shareef
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-07-2020; Springer Nature B.V
• Subjects: Ablation; Biochemistry; Biological and Medical Physics; Biomedical and Life Sciences; Biophysics; Cell Biology; Cell death; Cell Membrane - metabolism; Cholesterol; Cholesterol - metabolism; Electroporation; Kinetics; Life Sciences; Lipid membranes; Lipids; Membrane Biology; Membranes; Nanotechnology; Neurobiology; Original Article; Pore formation; Porosity; Prairies; Probability; Short pulses; Statistical analysis; Tension; Time dependence; Unilamellar Liposomes - chemistry; Unilamellar Liposomes - metabolism; Vesicles; Giant unilamellar vesicles; Membranes; IRE technique; Rate constant; Cholesterol; Pore formation
• ISSN: 0175-7571; 1432-1017
• DOI: 10.1007/s00249-020-01443-y

Irreversible electroporation (IRE) is primarily a nonthermal ablative technology that uses a series of high-voltage and ultra-short pulses with high-frequency electrical energy to induce cell death. This paper presents the influence of cholesterol on the IRE-induced probability of pore formation and the rate constant of pore formation in giant unilamellar vesicles (GUVs). The GUVs are prepared by a mixture of dioleoylphosphatidylglycerol (DOPG), dioleoylphosphatidylcholine (DOPC) and cholesterol using the natural swelling method. An IRE signal of frequency 1.1 kHz is applied to the membranes of GUVs. The probability of pore formation and the rate constant of pore formation events are obtained using statistical analysis from several single GUVs. The time-dependent fraction of intact GUVs among all those examined is fitted to a single exponential decay function from where the rate constant of pore formation is calculated. The probability of pore formation and the rate constant of pore formation decreases with an increase in cholesterol content in the membranes of GUVs. Theoretical equations are fitted to the tension-dependent rate constant of pore formation and to the probability of pore formation, which allows us to obtain the line tension of membranes. The obtained line tension increases with an increase in cholesterol in the membranes. The increase in the energy barrier of the prepore state, due to the increase of cholesterol in membranes, is the main factor explaining the decrease in the rate constant of pore formation.