Department of Morphology and Embryology, University of Ferrara, Via Fossato di Mortara 64/B, 44121 Ferrara, Italy.
Technol Cancer Res Treat. 2011 Oct;10(5):465-73. doi: 10.7785/tcrt.2012.500223.
Exposure of cells to an external sufficiently strong electric field results in the formation of pores across the membrane. This phenomenon, termed electropermeabilization, permits the transport of poorly permeant molecules into cytosol. In clinical practice, cell membrane permeabilization for drug electrotransfer is achieved using the ESOPE pulse protocol (1000 V/cm, 8 pulses, 100 μs, 5 kHz). The aim of this study was to investigate several combinations of electric field amplitude and pulse number able to induce electropermeabilization as the one observed when the ESOPE protocol was applied. Decreasing electric field amplitudes (1000 to 300 V/cm) in combination with increasing number of pulses (8 to 320) were applied to in vitro MG63 cells. Propidium iodide and Calcein blue AM uptake were used to evaluate cell electropermeabilization and viability. Results showed that the threshold of local electric field needed to obtain electropermeabilization decreased exponentially with increasing the number of pulses delivered (r2 5 0.92, p<0.0001). The absorbed dose threshold was dependent on the number of pulses for each voltage applied (r2 5 0.96, p<0.0001). In conclusion, the possibility of applying an increased number of pulses rather than increasing the electric field amplitude to perform electropermeabilization, may become an important tool for electropermeabilization-related clinical applications.
细胞暴露于外部足够强的电场会导致细胞膜形成孔道。这种现象称为电穿孔，允许不易渗透的分子进入细胞质。在临床实践中，通过使用 ESOPE 脉冲方案（1000 V/cm、8 个脉冲、100 μs、5 kHz）实现细胞膜通透性增强以进行药物电转移。本研究的目的是研究几种电场幅度和脉冲数的组合，以诱导与应用 ESOPE 方案时观察到的电穿孔相类似的电穿孔。将体外 MG63 细胞应用的电场强度（1000 至 300 V/cm）逐渐降低，并结合脉冲数量（8 至 320）逐渐增加。碘化丙啶和钙黄绿素 AM 摄取用于评估细胞的电穿孔和活力。结果表明，获得电穿孔所需的局部电场阈值随施加脉冲数量的增加呈指数下降（r2 5 0.92，p<0.0001）。对于每个应用的电压，吸收剂量阈值取决于施加的脉冲数（r2 5 0.96，p<0.0001）。总之，增加施加的脉冲数而不是增加电场强度来进行电穿孔的可能性，可能成为电穿孔相关临床应用的重要工具。
