A new method for the ablation of undesirable tissue such as cells of a cancerous or non-cancerous tumor is disclosed. It involves the placement of electrodes into or near the vicinity of the undesirable tissue through the application of electrical pulses causing irreversible electroporation of the cells throughout the entire area of the undesirable tissue. The electric pulses irreversibly permeate the cell membranes, thereby invoking cell death. The irreversibly permeabilized cells are left in situ and are removed by the body immune system. The amount of tissue ablation achievable through the use of irreversible electroporation without inducing thermal damage is considerable.

Tissue ablation with irreversible electroporation

Electric field-mediated fusion and related electrical phenomena.

Irreversible electroporation (IRE) is a new tissue ablation technique in which micro to millisecond electrical pulses are delivered to undesirable tissue to produce cell necrosis through irreversible cell membrane permeabilization. IRE affects only the cell membrane and no other structure in the tissue. The goal of the study is to test our IRE tissue ablation methodology in the pig liver, provide first experience results on long term histopathology of IRE ablated tissue, and discuss the clinical implications of the findings. The study consists of: a) designing an IRE ablation protocol through a mathematical analysis of the electrical field during electroporation; b) using ultrasound to position the electroporation electrodes in the predetermined locations and subsequently to monitor the process; c) applying the predetermined electrotroporation pulses; d) performing histolopathology on the treated samples for up to two weeks after the procedure; and e) correlating the mathematical analysis, ultrasound data...

https://journals.sagepub.com/doi/pdf/10.1177/153303460700600106

Irreversible electroporation: a new ablation modality--clinical implications.

The considerable amount of activity in the field of electrofusion and electropermeabilization is very promising from the point of view of new insights into biomembranes and new technologies in the future for the production of new compounds and modification of cell systems for nutrition, energy production and the removal of waste products. It is particularly gratifying to see how basic science has provided the foundation for a useful technology, although in some cases the time needed to develop an application is very long. In other cases, it is necessary to overcome the difficulties posed by existing schools of thought which have been shown to be wrong. It is fascinating to observe the many developments and discoveries in the areas of physics, material science, space technology and electronics which are just waiting to be applied to biological systems. An increased interdisciplinary collaboration between physicists and biologists could provide considerable impetus to biology and its application in technology. However, this can only be achieved if basic research into biological membranes is accelerated. The techniques for electrical breakdown, electropermeabilization and electrofusion could be an important tool in this process, since we cannot rule out the possibility that the high electrical fields occurring naturally in the membrane play an important role in the selective transport of substances across the membrane as well as in natural regulatory processes.

Electrical breakdown, electropermeabilization and electrofusion

A microfluidic system was fabricated on a glass chip to study mobilization of biological cells on-chip. Electroosmotic and/or electrophoretic pumping were used to drive the cell transport within a network of capillary channels. Whole cells such as Saccharomyces cerevisiae, canine erythrocyte, and Escherichia coli were employed in this work. Photographs are presented to illustrate how cells are selected and transported from one location to another within the capillary network, with velocities up to about 0.5 mm/s in capillaries with a 15- × 55-μm cross section. The mixing of canine erythrocytes with the lysing agent sodium dodecyl sulfate, at an intersection within the chip, was performed to demonstrate that cell selection and subsequent reaction can be accomplished within the microchip.

Transport, manipulation, and reaction of biological cells on-chip using electrokinetic effects.

Dielectric Breakdown of Cell Membranes

A Coulter Counter is a measuring device for counting and sizing non-conducting particles suspended in a conducting medium. This instrument is based on the principle that the electrical resistance in a small orifice, across which a voltage is applied, will change when a suspension of non-conducting particles is sucked through it. The current or voltage pulses arising are, to a first approximation, proportional to the size of the particles (size = shape factor X volume); this means that after linear electronic amplification and subsequent pulse height analysis the size distribution of each population under investigation can be obtained. Using conventional Coulter Counters, however, the measured size distribution is generally strongly distorted (skewed) due to inhomogeneities in the electric field strength in and near of the orifice; the pulse height becomes dependent on the path and orientation of each particle in the orifice (GROVER et al., 1969a, b, 1972; THOM, 1972). As described previously (ZIMMERMANN et al., 1973) the distortion arising from the inhomogeneous field can be eliminated by hydrodynamic focusing of the suspension flow. Then the particles travel on the same pathway, parallelly oriented, along the central axis through the orifice, and a true measurement of the real size distribution of the population can be obtained.

F. Riemann

Papers

Dielectric Breakdown of Cell Membranes

Dielectric Breakdown of Cell Membranes