Ivorra Antoni, Al-Sakere Bassim, Rubinsky Boris, Mir Lluis M
Department of Bioengineering, Department of Mechanical Engineering and Graduate Programin Biophysics, University of California at Berkeley, Berkeley, CA 94720, USA.
Phys Med Biol. 2008 Nov 21;53(22):6605-18. doi: 10.1088/0031-9155/53/22/020.
Electroporation is used in tissue for gene therapy, drug therapy and minimally invasive tissue ablation. The electrical field that develops during the application of the high voltage pulses needs to be precisely controlled. In the region to be treated, it is desirable to generate a homogeneous electric field magnitude between two specific thresholds whereas in other regions the field magnitude should be as low as possible. In the case of irregularly shaped tissue structures, such as bulky tumors, electric field homogeneity is almost impossible to be achieved with current electrode arrangements. We propose the use of conductive gels, matched to the conductivity of the tissues, to fill dead spaces between plate electrodes gripping the tissue so that the electric field distribution becomes less heterogeneous. Here it is shown that this technique indeed improves the antitumor efficacy of electrochemotherapy in sarcomas implanted in mice. Furthermore, we analyze, through finite element method simulations, how relevant the conductivity mismatches are. We found that conductivity mismatching errors are surprisingly well tolerated by the technique. Gels with conductivities ranging from 5 mS cm(-1) to 10 mS cm(-1) will be a proper solution for most cases.
电穿孔用于组织的基因治疗、药物治疗和微创组织消融。施加高压脉冲期间产生的电场需要精确控制。在待治疗区域，期望在两个特定阈值之间产生均匀的电场强度，而在其他区域，电场强度应尽可能低。在诸如大体积肿瘤等形状不规则的组织结构的情况下，使用当前的电极布置几乎不可能实现电场均匀性。我们建议使用与组织电导率相匹配的导电凝胶来填充夹住组织的平板电极之间的死腔，以使电场分布变得不那么不均匀。在此表明，该技术确实提高了电化学疗法对植入小鼠的肉瘤的抗肿瘤疗效。此外，我们通过有限元方法模拟分析了电导率失配的相关性。我们发现该技术对电导率失配误差的耐受性出奇地好。电导率范围为5 mS cm(-1)至10 mS cm(-1)的凝胶在大多数情况下将是合适的解决方案。
