Thiruvallur R. Gowrishankar

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—Electroporation has been widely used to manipulate cells and tissues, but quantitative understanding of electrical behavior in cell membranes has not been achieved. According to the transient aqueous pore hypothesis, pore creation and expansion is a nonlinear, hysteretic process. Different membrane sites respond locally to their own transmembrane voltage(More)
Conventional electroporation (EP) changes both the conductance and molecular permeability of the plasma membrane (PM) of cells and is a standard method for delivering both biologically active and probe molecules of a wide range of sizes into cells. However, the underlying mechanisms at the molecular and cellular levels remain controversial. Here we(More)
Extremely large but very short (20 kV/cm, 300 ns) electric field pulses were reported recently to non-thermally destroy melanoma tumors. The stated mechanism for field penetration into cells is pulse characteristic times faster than charge redistribution (displacement currents). Here we use a multicellular model with irregularly shaped, closely spaced cells(More)
Science increasingly involves complex modeling. Here we describe a model for cell electroporation in which membrane properties are dynamically modified by poration. Spatial scales range from cell membrane thickness (5 nm) to a typical mammalian cell radius (10  $$\upmu$$ μ m), and can be used with idealized and experimental pulse waveforms. The model(More)
The membrane of a living cell consists of a bilayer of amphipolar lipid molecules as well as much larger proteins. Transmembrane potentials of up to 120 mV are physiologic and well tolerated, but when the potential is more than 300 mV, this lipid bilayer is unstable. Pores are then formed through which measurable flow of ions can occur. We follow currents(More)
Pulse trains are widely used in electroporation (EP) for both general biomedical research and clinical applications such as nonthermal tumor ablation. Here we use a computational method based on a meshed transport network to investigate a cell system model's response to a train of identical, evenly spaced electric field pulses. We obtain an unexpected(More)
Cells exposed to electric fields are often confined to a small volume within a solid tissue or within or near a device. Here we report on an approach to describing the frequency and time domain electrical responses of a spatially confined spherical cell by using a transport lattice system model. Two cases are considered: (1) a uniform applied field created(More)
The frequency and time domain transmembrane voltage responses of a cylindrical cell in an external electric field are calculated using a transport lattice, which allows solution of a variety of biologically relevant transport problems with complex cell geometry and field interactions. Here we demonstrate the method for a cylindrical membrane geometry and(More)
Conditions that stimulate action potentials in one or more nerves is of widespread interest. Axon and nerve models are usually based on two dimensional pre-specified lumped equivalents that assume where currents will flow. In contrast, here we illustrate creation of three dimensional (3D) system models with a transport lattice of interconnected local models(More)