Electroporation-Enhanced Nonviral Gene Transfer for the Prevention or Treatment of Immunological, Endocrine and Neoplastic Diseases

Abstract

Nonviral gene transfer is markedly enhanced by the application of in vivo electroporation (also denoted electro-gene transfer or electrokinetic enhancement). This approach is safe and can be used to deliver nucleic acid fragments, oligonucleotides, siRNA, and plasmids to a wide variety of tissues, such as skeletal muscle, skin and liver. In this review, we address the principles of electroporation and demonstrate its effectiveness in disease models. Electroporation has been shown to be equally applicable to small and large animals (rodents, dogs, pigs, other farm animals and primates), and this addresses one of the major problems in gene therapy, that of scalability to humans. Gene transfer can be optimized and tissue injury minimized by the selection of appropriate electrical parameters. We and others have applied this approach in preclinical autoimmune and/or inflammatory diseases to deliver either cytokines, anti-inflammatory agents or immunoregulatory molecules. Electroporation is also effective for the intratumoral delivery of therapeutic vectors. It strongly boost DNA vaccination against infectious agents (e.g., hepatitis B virus, human immunodeficiency virus-1) or tumor antigens (e.g., HER-2/neu, carcinoembryonic antigen). In addition, we found that electroporation-enhanced DNA vaccination against islet-cell antigens ameliorated autoimmune diabetes. One of the most likely future applications, however, may be in intramuscular gene transfer for systemic delivery of either endocrine hormones (e.g., growth hormone releasing hormone and leptin), hematopoietic factors (e.g., erythropoietin, GM-CSF), antibodies, enzymes, or numerous other protein drugs. In vivo electroporation has been performed in humans, and it seems likely it could be applied clinically for nonviral gene therapy.

Control by pulse parameters of DNA electrotransfer into solid tumors in mice

“…[3][4][5] Gene therapy using electropulsation as a gene delivery method has already entered clinical trials for the treatment of different tumor types in cancer patients and for vaccination. [6][7][8][9] Electrotransfer of plasmid DNA has been assayed and used in many different tissues, such as skin, muscle, liver, tumors, lung, cornea, kidney, brain, cartilage, bladder, carotid artery and tendon. [6][7][8] However, most studies were carried out in muscle, where high transfection efficiencies can be obtained.…”

“…[6][7][8][9] Electrotransfer of plasmid DNA has been assayed and used in many different tissues, such as skin, muscle, liver, tumors, lung, cornea, kidney, brain, cartilage, bladder, carotid artery and tendon. [6][7][8] However, most studies were carried out in muscle, where high transfection efficiencies can be obtained. So far, the transfection efficiencies obtained in tumors following electropulsation have been smaller compared to other tissues, [10][11][12] but a significant therapeutic effect can nevertheless be obtained by electrotransfer of therapeutic genes into tumors.…”

“…So far, the transfection efficiencies obtained in tumors following electropulsation have been smaller compared to other tissues, [10][11][12] but a significant therapeutic effect can nevertheless be obtained by electrotransfer of therapeutic genes into tumors. 7,8 Classically, electrically mediated gene delivery is obtained by submitting the target to a train of pulses lasting a few milliseconds or 100 microseconds at a 1 Hz frequency, and adjusting the voltage to the electrode width. [10][11][12][13][14][15][16] A new protocol with high transfection efficacy in muscle and skin has recently been described, consisting of a combination of one high-field (HV, B1000 V cm À1 ) and one (or several) low-field (LV, B100 V cm À1 ) pulse.…”

DNA immunization using constant-current electroporation affords long-term protection from autochthonous mammary carcinomas in cancer-prone transgenic mice

“…Recent technological advancements in increasing DNA vaccine uptake and expression using a constant-current electroporation (CCE) technique, could help to overcome this limitation. [1][2][3] Many recent studies using in vivo electroporation to enhance the uptake and expression of DNA vaccines have been performed with high doses of plasmid and voltagebased methods. This technique involves delivering a predetermined voltage between the electrodes, without taking into account the resistance of the tissue to be treated.…”

A Numerical Model of Skin Electropermeabilization Based on In Vivo Experiments

“…8 Reversible increase of cell membrane permeability caused by electric field-electroporation-is currently one of the most efficient and simple non-viral methods of gene transfer. 10,19 Cell membrane is permeabilized when the threshold transmembrane voltage is reached, i.e., when the external electric field is above the threshold value. Induced transmembrane potential depends on cell and tissue parameters (tissue conductivity, cell size, shape, and distribution) 12,20,22 and pulse parameters (pulse duration, amplitude, and number of pulses).…”