A Vivens Ex Vivo Study on the Synergistic Effect of Electrolysis and Freezing on the Cell Nucleus

Abstract

Freezing—cryosurgery, and electrolysis—electrochemical therapy (EChT), are two important minimally invasive surgery tissue ablation technologies. Despite major advantages they also have some disadvantages. Cryosurgery cannot induce cell death at high subzero freezing temperatures and requires multiple freeze thaw cycles, while EChT requires high concentrations of electrolytic products—which makes it a lengthy procedure. Based on the observation that freezing increases the concentration of solutes (including products of electrolysis) in the frozen region and permeabilizes the cell membrane to these products, this study examines the hypothesis that there could be a synergistic effect between freezing and electrolysis in their use together for tissue ablation. Using an animal model we refer to as vivens ex vivo, which may be of value in reducing the use of animals for experiments, combined with a Hematoxylin stain of the nucleus, we show that there are clinically relevant protocols in which the cell nucleus appears intact when electrolysis and freezing are used separately but is affected by certain combinations of electrolysis and freezing.

Cryoelectrolysis—electrolytic processes in a frozen physiological saline medium

“…The first study employed a protocol in which electrolysis was delivered first, followed by freezing. Experiments on animal tissue have confirmed our hypothesis and have shown that cryoelectrolysis is more effective at cell ablation than either cryosurgery or electrolytic ablation, alone (Lugnani et al, 2015). …”

“…Diffusion and iontophoresis driven electro-osmosis, are the physical mechanisms that cause the propagation of the pH front from the electrode outward. The electro-osmotic flow is an important aspect of electrolytic ablation in tissue (Lugnani et al, 2015; Phillips et al, 2015a; Phillips et al, 2015b; Rubinsky et al, 2015; Rubinsky et al, 2016). The flow is from the anode to the cathode.…”

“…From these experiments we chose values of 400 mA, 200 mA and 50 mA. The range of electrical currents tested are typical to clinical electrolytic ablation procedures (Nilsson et al, 2000; Lugnani et al, 2015). Similarly, preliminary experiments were performed with freezing only to evaluate the time of freezing needed to obtained measurable frozen lesions in our experimental configuration.…”

“…The combinations examined include: electrolysis and electroporation; cryosurgery and electroporation; and cryosurgery and electrolysis (Lugnani et al, 2015; Rubinsky et al, 2015; Stehling et al, 2016). This paper pertains to the latter, the combination of cryosurgery and electrolysis, termed cryoelectrolysis (Lugnani et al, 2015), which is a largely unexplored process. Cryoelectrolysis, is marked by its potential to utilize the advantages of both cryosurgery and electrolytic ablation while overcoming their disadvantages.…”

“…Because the production of the electrolytic products is a time dependent reaction, decreasing the amount of electrolytic compounds needed for cell ablation, should shorten the time of an electrolytic induced mechanism of cell ablation. This is the basic principle of the cryoelectrolytic ablation concept proposed in Lugnani et al (2015). In that concept, the targeted tissue is first treated with electrolysis to generate products of electrolysis in the targeted volume; after which the targeted tissue is frozen to increase the local concentration and the exposure of the cell interior to the products of electrolysis in the frozen lesion.…”