University of Ljubljana, Faculty of Electrical Engineering, Slovenia.
University of Ljubljana, Faculty of Electrical Engineering, Slovenia.
Bioelectrochemistry. 2022 Apr;144:108004. doi: 10.1016/j.bioelechem.2021.108004. Epub 2021 Nov 23.
Electroporation threshold depends on the membrane composition, with cholesterol being one of its key components already studied in the past, but the results were inconclusive. The aim of our study was to determine behaviour of planar lipid bilayers with varying cholesterol concentrations under electric field. This would give us a better insight into cholesterol effect on membrane properties during electroporation process, since cholesterol is one of the major components of biological membranes and plays a crucial role in membrane organisation, dynamics, and function. Planar lipid bilayers were prepared from phosphatidylcholine lipids with 0, 20, 30, 50 and 80 mol% cholesterol. Capacitance was measured using the discharge method. Results show no statistical difference of c between the cholesterol concentrations. Breakdown voltage U of planar lipid bilayers was measured by means of linear rising voltage with seven different slopes. Obtained results were fitted to a strength-duration curve, where parameter U represents minimal breakdown voltage, and parameter τ represents the inclination of the strength-duration curve. Adding cholesterol to planar lipid bilayer gradually increased its U until 50 mol% cholesterol concentration. Afterwards at 80 mol% U does not further increase, in fact it reduces by 20% of the U at 50 mol% cholesterol concentration.
电穿孔阈值取决于膜的组成，胆固醇就是过去已经研究过的关键成分之一，但结果尚无定论。我们的研究目的是确定在电场作用下具有不同胆固醇浓度的平面脂质双层的行为。这将使我们更深入地了解胆固醇在电穿孔过程中对膜性质的影响，因为胆固醇是生物膜的主要成分之一，在膜的组织、动力学和功能中起着至关重要的作用。平面脂质双层由含有 0、20、30、50 和 80 mol%胆固醇的磷脂组成。使用放电法测量电容。结果表明胆固醇浓度之间的 c 没有统计学差异。通过七种不同斜率的线性上升电压测量平面脂质双层的击穿电压 U。获得的结果拟合到强度-持续时间曲线，其中参数 U 表示最小击穿电压，参数 τ 表示强度-持续时间曲线的斜率。向平面脂质双层中添加胆固醇会逐渐增加其 U，直到胆固醇浓度达到 50 mol%。之后，当胆固醇浓度达到 80 mol%时，U 不再进一步增加，实际上比胆固醇浓度为 50 mol%时降低了 20%。
