Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia.
Jožef Stefan Institute, Ljubljana, Slovenia.
Radiol Oncol. 2024 Sep 15;58(3):406-415. doi: 10.2478/raon-2024-0047. eCollection 2024 Sep 1.
Administering gadolinium-based contrast agent before electroporation allows the contrast agent to enter the cells and enables MRI assessment of reversibly electroporated regions. The aim of this study was evaluation of contrast agent entrapment in Chinese hamster ovary (CHO) cells and comparison of these results with those determined by standard methods for assessing cell membrane permeability, cell membrane integrity and cell survival following electroporation.
Cell membrane permeabilization and cell membrane integrity experiments were performed using YO-PRO-1 dye and propidium iodide, respectively. Cell survival experiments were performed by assessing metabolic activity of cells using MTS assay. The entrapment of gadolinium-based contrast agent gadobutrol inside the cells was evaluated using T relaxometry of cell suspensions 25 min and 24 h after electroporation and confirmed by inductively coupled plasma mass spectrometry.
Contrast agent was detected 25 min and 24 h after the delivery of electric pulses in cells that were reversibly electroporated. In addition, contrast agent was present in irreversibly electroporated cells 25 min after the delivery of electric pulses but was no longer detected in irreversibly electroporated cells after 24 h. Inductively coupled plasma mass spectrometry showed a proportional decrease in gadolinium content per cell with shortening of T relaxation time ( = 0.88 and = 0.0191).
Our results demonstrate that the contrast agent is entrapped in cells exposed to reversible electroporation but exits from cells exposed to irreversible electroporation within 24 h, thus confirming the hypothesis on which detection experiments were based.
在电穿孔前给予钆基造影剂可以使造影剂进入细胞，并能够对可逆电穿孔区域进行 MRI 评估。本研究的目的是评估造影剂在仓鼠卵巢（CHO）细胞中的滞留，并将这些结果与评估电穿孔后细胞膜通透性、细胞膜完整性和细胞存活率的标准方法进行比较。
使用 YO-PRO-1 染料和碘化丙啶分别进行细胞膜通透性和细胞膜完整性实验。通过 MTS 测定评估细胞代谢活性来进行细胞存活率实验。电穿孔后 25 分钟和 24 小时，通过细胞悬液的 T 弛豫测量评估细胞内钆基造影剂钆布醇的滞留情况，并通过电感耦合等离子体质谱法进行确认。
在可逆电穿孔的细胞中，在施加电脉冲后 25 分钟和 24 小时检测到造影剂。此外，在施加电脉冲后 25 分钟不可逆电穿孔的细胞中存在造影剂，但在 24 小时后不再检测到不可逆电穿孔的细胞中的造影剂。电感耦合等离子体质谱法显示，每个细胞的钆含量与 T 弛豫时间的缩短呈比例下降（ = 0.88 和 = 0.0191）。
我们的结果表明，在暴露于可逆电穿孔的细胞中，造影剂被捕获，但在暴露于不可逆电穿孔的细胞中，在 24 小时内从细胞中逸出，从而证实了检测实验所基于的假设。
