Synergistic effects of local temperature enhancements on cellular responses in the context of high-intensity, ultrashort electric pulses

Abstract

Results of self-consistent analyses of cells show the possibility of temperature increases at membranes in response to a single nanosecond, high-voltage pulse, at least over small sections of the membrane. Molecular Dynamics simulations indicate that such a temperature increase could facilitate poration, which is one example of a bio-process at the plasma membrane. Our study thus suggests that the use of repetitive high-intensity voltage pulses could open up possibilities for a host of synergistic bio-responses involving both thermal and electrically driven phenomena.

Cell Death Induced by Subnanosecond Pulsed Electric Fields at Elevated Temperatures

“…9 are in agreement with the experimental trends in that no pore formation occurs at 25 • C. However, at 47 • C, there is a clear indication of pore formation at 0.75 ns The results underscore the role of temperature in facilitating and accelerating the poration process. A similar trend toward a synergism involving both thermal and electrically driven biophenomena had recently been reported [36].…”

“…This observation is evident in the MD simulations of a lipid layer with constant electric field strength of 0.5 V/nm at 25 • C and 47 • C. The high background electric field is typically used in MD simulations to probe poration [36]. It serves as an accelerated test of the pore formation process, since low electric fields would take inordinately long simulation time.…”

Membrane Heating in Living Tissues Exposed to Nonthermal Pulsed EM Fields

“…Our findings suggest that whenever the pulse duration is small compared to the thermal relaxation constant of the cell membrane, and the membrane capacitance drops to its low asymptotic high-frequency value in the pulse spectral bands, one may observe a steep increase in the membrane temperature, up to physiologically significant levels, the average (cytoplasm) temperature remaining essentially unaffected. Similar conclusions were obtained in [14] following a more sophisticated approach which combines Smoluchowski equation to describe membrane response, the heat equation and molecular dynamics simulations, to gauge the impact of localized membrane heating on membrane poration. In this paper we extend the analysis of [13] to the more realistic case where the cell is part of a bio-tissue.…”

Rhodamine B as an optical thermometer in cells focally exposed to infrared laser light or nanosecond pulsed electric fields

“…nsPEFs can be used to transiently permeabilize the plasma membranes of cells [11,12], but despite having high peak power, the effect of these ultrashort pulses are considered to be nonthermal due to the low average energy density that they deliver. Interestingly, it has been shown analytically that the application of nsPEFs to cells could result in both thermal (Joule heating) and electrical effects [13]. Thus, like infrared laser light, local temperature measurements of biological samples exposed to nsPEFs are necessary to better understand the mechanisms involved in these effects.…”