Voltage commutator for multiple electrodes in gene electrotransfer of skin cells

Abstract

Gene electrotransfer is a promising nonviral method for transferring genes into the cells. The method is based on electroporation and it has been proven to be successful in both in vivo and in vitro conditions. This phenomenon occurs when cells are exposed to electric field established by high and low voltage pulses. The first high voltage pulse results in a high level of cell permeabilization (permeabilization pulse), while the second low voltage pulse provides a driving force for transport of DNA into cells (electrophoretic pulse). The efficiency and successfulness of gene electrotransfer significantly depends on electrical devices in use. A voltage commutator presents one of the most important electrical components in bipolar or multi electrodes devices. Its main function is commutating high and low voltage pulses, which are delivered through the microelectrodes to the skin cells. Even though gene electrotransfer is based on electroporation, our previous voltage commutator for electroporation is appropriate for gene electrotransfer because of its slow switching between voltage pulses. The aim of this study was to develop and test a new voltage commutator with multiple outputs and faster switching capabilities. We achieved that with high speed MOSFET drivers, which can withstand a voltage up to 600 V with commutation delay time less than 170 ns. We examined and confirmed voltage commutator switching capability with measuring deviation of the output signal in the frequency range of gene electrotransfer. In addition, we discovered that voltage commutator is capable of driving voltage pulses with even higher frequency. We also made every one of ten voltage commutator outputs independently programmable to deliver its own sequence of high and low voltage pulses. We demonstrated that with commutating a typical gene electrotransfer pulse sequence, consisting of a high voltage pulse and followed by a low voltage pulse. Due to voltage commutator scalability, the number of outputs can be increased for future requirements.