Electroporation-based treatments with new high-frequency electroporation pulses (2018-2021)

Electroporation-based treatments with new high-frequency electroporation pulses (2018-2021)
Head: Assist. Prof. Matej Reberšek, Faculty of Electrical Engineering, University of Ljubljana
Partner: /
Funding: ARRS – Slovenian Research Agency
Code: J2-9227

 

The project is funded by the Slovenian Research Agency (ARRS).

Member of University of Ljubljana

University of Ljubljana, Faculty of Electrical Engineering

Code
J2-9227
Project
Electroporation-based treatments with new high-frequency electroporation pulses
Period
1.7.2018 - 30.6.2021
Amount of financing
1.3 FTE
Head

Matej Reberšek

Research activity
Engineering sciences and technologies - Systems and cybernetics
Research Organisation
Abstract

More than 10 000 patients have been treated with electroporation-based treatments in more than 150 hospitals in Europe after the development of the first clinical device in 2006, comparable values are also for USA. Moreover, there are currently ongoing tens of clinical trials worldwide evaluating electroporation-based treatments.

In electroporation-based treatments, the electroporation pulses have fundamental frequency of 5 kHz or lower. The tissues in the body have at these frequencies a large impedance range. The electric field distribution in the body is thus very inhomogeneous during the delivery of classical electroporation pulses. Because of the inhomogeneous electric field distribution inside the body, the effects of electroporation-based treatments are also inhomogeneous in the body and thus less effective. Electroporation-based treatments thus require extensive numerical optimizations to cover the entire treatment area with sufficient electric field. At higher pulse frequencies tissues in the body have a smaller impedance range, and recent studies suggest that with shorter high-frequency bipolar electroporation pulses, electroporation of the tissues in the body could be more homogeneous, and that high-frequency electroporation pulses can achieve effective treatment without muscle contraction.

Our group regularly follows the development of commercial and laboratory prototype electroporation devices and we conclude that the first problem arises as there are no suitable electroporation devices for thoroughly analysing the effects of high-frequency electroporation pulses. The second problem arises as some groups independently to high-frequency treatments researchers concluded that high-frequency bipolar electroporation pulses can cause cancellation effect. Therefore we will develop a new prototype electroporation device that will generate high-frequency monopolar, bipolar and asymmetric bipolar electroporation pulses from 100 ns to 1 ms pulse duration, pulse amplitude up to 4 kV, and pulse repetition rate up to 5 MHz. For the first time, we will analyse thoroughly the high-frequency electroporation pulses in vitro as well as in vivo. Current electroporation models for electric field distribution in tissue are stationary and the changing of tissue impedance with the frequency of the pulses is not included. We will develop a new model in frequency domain and include the frequency characteristics of the tissue, and thus more precisely determine the electric field distribution of the high-frequency electroporation pulses in the tissue. Previous studies suggest a presence of cancellation effect in the field of high-frequency electroporation pulses. We will analyse thoroughly the range of electroporation pulse parameters and determine the equivalent parameters of high-frequency electroporation pulses regarding currently used classical electroporation pulses. We will systematically analyse the findings that the high-frequency electroporation pulses distribute in the tissue more homogeneously than classical electroporation pulses by indirect observation of electric field distribution using magnetic resonance imaging, and the findings that at the equivalent high-frequency electroporation pulses do not cause muscle contractions and pain by quantitative evaluation of muscle contractions and unpleasant sensations.

The expected results would significantly influence the development of current electroporation-based treatments because they would improve coverage of the entire treatment area with sufficient electric field. This would most likely increase the efficiency of the treatments, reduce the scattering of the results and simplify the treatment planning. The expected results would also reduce the muscle contraction and excitation of nerves and thus reduce the unpleasant sensations, movement of tissue and electrodes during the treatment, and improve the safety of treatments close to nerves.

Researchers

Link to SICRIS.

The phases of the project and their realization

Organization of the project is closely linked to the objectives pursued. The principal research institution in the project is the University of Ljubljana (UL), Faculty of Electrical Engineering, one of the leading research institutions in the world in the field of new electroporation devices, modelling electric field distribution and in vitro electroporation experiments. In addition, the principal research institution has prominent experience in analysis of tissue impedance, muscle contractions and unpleasant sensations due to electroporation pulses. The collaborating research institution is the Jozef Stefan Institute (IJS) which is one of the leading research institutions in the world in the field of in vivo magnetic resonance imaging of electroporation effects. In the field of the action potential, muscle contractions and unpleasant sensations we will collaborate with dr. Rodney Philip O’Connor acknowledged expert in the field of neurophysiology and neurobiology with whom UL cooperates on bilateral project. Animal work will be performed in collaboration with Department of Experimental Oncology, Institute of Oncology, Ljubljana, Slovenia that has many years of experience with animal work, and with whom UL regularly cooperates. With dr. Rodney Philip O’Connor from École Nationale Supérieure des Mines de Saint-Étienne, France and with prof. Gregor Serša from Institute of Oncology, Ljubljana, Slovenia we have signed a »letter of intent« to collaborate in the proposed project. The participating research institutions are complementary and highly competent in theoretical and practical knowledge regarding issues to be investigated.

Effective management of knowledge and exploitation will be assured as well as compliance with provisions of ARRS projects. The project leader is responsible for:

  • overall management of the project,
  • preparation of the meetings,
  • timely execution of tasks defined in WPs and preparation of reports,
  • timely delivery of all data identified as deliverables, and
  • control of the budget.

The work on the proposed project will be organised in five work packages (WP):

In Work package 1 of the project, we will develop a new prototype electroporator that will allow systematic analysis of the high-frequency pulses in vitro (WP 3) and in vivo (WP 4; described in WP 1). In Work package 2 of the project we will develop a new frequency-domain electroporation model that will allow calculation of the distribution of the electric field in the inhomogeneous tissue. The tissue model will be built by means of magnetic resonance imaging (WP 4) and validated by in vitro (WP 3) and in vivo experiments (WP 4; described in WP 2). In Work package 3 of the project, we will use the new prototype electroporator developed in WP 1 to systematically analyse in vitro the effect of the high-frequency electroporation pulses on permeabilization, molecular transport, and cell survival. Comparing the results with classical electroporation, we will also define equivalent high-frequency electroporation pulses that will be used in WP 4 (described in WP 3).

In Work package 4 of the project, we will first submit applications to obtain permits for the experiments in WP 4. The application should be submitted at least one year before the planned experiments. In case of complication with one of the application we have 6 months of reserve. After we will obtain the permissions for the experiments and develop the new prototype electroporator in WP 1, we will start with the in vivo experiments. By means of magnetic resonance imaging, we will define the mice leg tissue structure for the numerical model in WP 2, compare the electric field distribution of classical electroporation pulses with equivalent high-frequency electroporation pulses determined in WP 3. Within this work package, we will also determine whether high-frequency electroporation pulses have a less significant effect on muscle contraction and unpleasant sensations compared to classical electroporation pulses. After finishing all the experiments in this project, we will take into account all the results obtained in WP 2, 3 and 4, and define the guidelines for more efficient and less painful electroporation-based treatments (described in WP 4).

In Work package 5 of the project, we will seek the opportunities to protect new knowledge and disseminate results to potential partners in industry. Also, regular meetings and financial reporting to ARRS agency will be organized. By tightening the cooperation between both partners, the project will serve as a base for the preparation of spin-off proposal for international calls, in particular for Horizon 2020 (described in WP 5).

Citations for bibliographic records

N/A.