Nucleic acids electrotransfer in vivo: Mechanisms and practical aspects

Nucleic acids transfer has been steadily improving over the years and is slowly starting to fulfill its long awaited promises. In the beginning, viral approaches raised strong safety concerns that are now answered by various nonviral techniques. Among the physical approaches developed, nucleic acids electrotransfer is probably the one with the highest momentum. Here we review the present knowledge on the mechanistic and practical aspects of in vivo nucleic acids electrotransfer. For each step of this procedure we present different strategies that are used, with their advantages and drawbacks. As we report here, practical solutions have been found to overcome each limiting step in the procedure and to improve its outcome. Some crucial issues are beyond the application of the electric pulses itself, like the administration (i.e., in almost all of the cases, the injection) of the nucleic acids to the tissue or the body. High efficiency and safety are at reach if all the present knowledge and strategies are put to use. Electrotransfer is now a mature technique as proven by the fact that clinical trials using nucleic acids electrotransfer have already started within the past few years.