Intracranial Nonthermal Irreversible Electroporation: In Vivo Analysis

Abstract Aims Irreversible electroporation (IRE) ablation is a non-thermal ablation method based on the application of direct current between a multi-electrode catheter and skin electrode. The delivery of current through blood leads to electrolysis. Some studies suggest that gaseous (micro)emboli might be associated with myocardial damage and/or (a)symptomatic cerebral ischaemic events. The aim of this study was to compare the amount of gas generated during IRE ablation and during radiofrequency (RF) ablation. Methods and results In six 60–75 kg pigs, an extracorporeal femoral shunt was outfitted with a bubble-counter to detect the size and total volume of gas bubbles. Anodal and cathodal 200 J IRE applications were delivered in the left atrium (LA) using a 14-electrode circular catheter. The 30 and 60 s 40 W RF point-by-point ablations were performed. Using transoesophageal echocardiography (TOE), gas formation was visualized. Average gas volumes were 0.6 ± 0.6 and 56.9 ± 19.1 μL (P < 0.01) for each anodal and cathodal IRE application, respectively. Also, qualitative TOE imaging showed significantly less LA bubble contrast with anodal than with cathodal applications. Radiofrequency ablations produced 1.7 ± 2.9 and 6.7 ± 7.4 μL of gas, for 30 and 60 s ablation time, respectively. Conclusion Anodal IRE applications result in significantly less gas formation than both cathodal IRE applications and RF applications. This finding is supported by TOE observations.

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Nonthermal Irreversible Electroporation for Tissue Decellularization

Journal of Biomechanical Engineering ◽

10.1115/1.4001882 ◽

2010 ◽

Vol 132 (9) ◽

Cited By ~ 53

Author(s):

Mary Phillips ◽

Elad Maor ◽

Boris Rubinsky

Keyword(s):

Thermal Damage ◽

Irreversible Electroporation ◽

Electrical Parameters ◽

Irreversible Damage ◽

Tissue Scaffold ◽

Electrical Fields ◽

Nonthermal Irreversible Electroporation ◽

Tissue Scaffolding ◽

Living Tissues

Tissue scaffolding is a key component for tissue engineering, and the extracellular matrix (ECM) is nature’s ideal scaffold material. A conceptually different method is reported here for producing tissue scaffolds by decellularization of living tissues using nonthermal irreversible electroporation (NTIRE) pulsed electrical fields to cause nanoscale irreversible damage to the cell membrane in the targeted tissue while sparing the ECM and utilizing the body’s host response for decellularization. This study demonstrates that the method preserves the native tissue ECM and produces a scaffold that is functional and facilitates recellularization. A two-dimensional transient finite element solution of the Laplace and heat conduction equations was used to ensure that the electrical parameters used would not cause any thermal damage to the tissue scaffold. By performing NTIRE in vivo on the carotid artery, it is shown that in 3 days post NTIRE the immune system decellularizes the irreversible electroporated tissue and leaves behind a functional scaffold. In 7 days, there is evidence of endothelial regrowth, indicating that the artery scaffold maintained its function throughout the procedure and normal recellularization is taking place.

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Meiotic CENP-C is a shepherd: bridging the space between the centromere and the kinetochore in time and space

Essays in Biochemistry ◽

10.1042/ebc20190080 ◽

2020 ◽

Vol 64 (2) ◽

pp. 251-261

Author(s):

Jessica E. Fellmeth ◽

Kim S. McKim

Keyword(s):

Chromosome Segregation ◽

New Technologies ◽

Early Prophase ◽

Unique Role ◽

Kinetochore Assembly ◽

M Phase ◽

In Vivo Analysis ◽

Meiosis I

Abstract While many of the proteins involved in the mitotic centromere and kinetochore are conserved in meiosis, they often gain a novel function due to the unique needs of homolog segregation during meiosis I (MI). CENP-C is a critical component of the centromere for kinetochore assembly in mitosis. Recent work, however, has highlighted the unique features of meiotic CENP-C. Centromere establishment and stability require CENP-C loading at the centromere for CENP-A function. Pre-meiotic loading of proteins necessary for homolog recombination as well as cohesion also rely on CENP-C, as do the main scaffolding components of the kinetochore. Much of this work relies on new technologies that enable in vivo analysis of meiosis like never before. Here, we strive to highlight the unique role of this highly conserved centromere protein that loads on to centromeres prior to M-phase onset, but continues to perform critical functions through chromosome segregation. CENP-C is not merely a structural link between the centromere and the kinetochore, but also a functional one joining the processes of early prophase homolog synapsis to late metaphase kinetochore assembly and signaling.

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