Molecular Microdosimetry for Electric Fields and Eletroporation Mechanism

描述(由申请人提供)：电子干预在医学中广泛存在并不断增长，但基本的相互作用机制往往知之甚少。电穿孔就是一个主要的例子。传统的电穿孔被广泛应用于生物医学研究，通过经验调整将DNA、蛋白质、抗癌药物和荧光标记物输送到细胞中。最近发现的超电穿孔具有有限的药物传递能力，但通过与细胞器的相互作用而引起细胞内效应。超电穿孔还通过触发细胞凋亡来去除细胞，而过度的常规电穿孔则会导致坏死。绝大多数的研究应用都是在体外进行的，但对体内电穿孔的实验研究也在迅速增长。我们建议使用高级建模继续对电场与细胞和组织的相互作用进行基础研究。虽然我们将考虑局部加热和其他机制(例如，电压门控通道)，但我们将重点介绍电穿孔高度非线性行为的基本机制。在整个研究过程中，我们将通过创建相应的、现实的细胞和组织级别的模型来创建和扩展机械假设，这些模型可以解释：(1)对简单和复杂应用波形的电响应，(2)显微镜(细胞级别)加热的量，以及(3)特定离子和分子的场诱导传输。我们的方法涉及电、热和化学系统的耦合模型。每个系统模型由大量相互连接的本地模型组成，这些模型相互作用以定义系统响应。这些方法使我们能够为外质膜和内部细胞器膜创建具有逼真、不规则形状的细胞模型。我们的细胞级模型可以与组织级模型集成，以进行电、热和化学反应。化学反应模型可以进一步扩展到包括药代动力学模型。这集成了细胞和组织水平的模型，以描述整个身体水平的化学变化。我们将通过将建模结果与已发表的结果和合作者的实验结果进行直接比较来测试我们的基于机制的模型。这种基于机制的建模能力将通过在大参数空间中提供对不同脉冲波形的细胞响应的初步评估来辅助生物电干预的工程设计。这项拟议的研究与公共卫生相关，因为定量的机制理解对于开发有效的生物电动医疗设备和干预措施至关重要，同时将副作用降至最低。

DESCRIPTION (provided by applicant): Electrical interventions in medicine are widespread and growing, but basic interaction mechanisms are often poorly understood. Electroporation is an major example. Conventional electroporation is widely used in biomedical research with empirically adjusted delivery of DNA, proteins, cancer drugs and fluorescent markers into cells. Recently discovered supra-electroporation has limited drug delivery capability, but causes intracellular effects by interactions with organelles. Supra-electroporation also removes cells by triggering apoptosis whereas excessive conventional electroporation leads to necrosis. The great majority of research applications are in vitro, but there is rapidly growing empirical investigation of electroporation in vivo. We propose continued basic investigation of the interaction of electric fields with cells and tissue by using advanced modeling. Although we will consider localized heating and other mechanisms (e.g. voltage-gated channels) we will focus on the fundamental mechanisms for the highly non-linear behavior of electroporation. Throughout our investigation we will create and extend mechanistic hypotheses by creating corresponding, realistic cell- and tissue-level models that can account for the: (1) electrical response to simple and complex applied waveforms, (2) amount of Thicroscopic (cell level) heating, and (3) field-induced transport of particular ions and molecules. Our methods involve coupled electrical, thermal and chemical system models. Each system model consists of a large number of interconnected local models that interact to define a system response. These methods allow us to create cell models with realistic, irregular shapes for the outer plasma membrane and also for internal organelle membranes. Our cell-level models can be integrated with tissue-level models for electrical, thermal and chemical responses. Chemical response models can be further expanded to involve pharmacokinetic models. This integrates cell- and tissue-level models to describe chemical changes at the whole body level. We will test our mechanistic-based models by direct comparison of modeling results with published results and experimental findings of our collaborators. This mechanism-based modeling capability will assist engineering of bioelectric interventions by providing preliminary assessment of cellular responses for different pulsing waveforms in a large parameter space. The proposed research is relevant to public health because quantitative mechanistic understanding is critical to developing effective bioelectric medical devices and interventions while minimizing side effects.