High-Density Microneedle Array (HIDMA): An in vivo Electroporation Method for Low-Voltage Gene Delivery

In this work, we report a novel in vivo electroporation method for gene delivery utilizing high-density microneedle array (HIDMA). Owing to the minimized needle spacing, hexagonal distribution, and tri-polarity electric connection of the device, the low voltage and uniform electric field during electroporation can dramatically reduce cell damage and enhance delivery efficiency. The HIDMA is constructed with modified acupuncture needles, and can be customized for both superficial and deep tissues with different electroporation areas. According to the in vivo experiments on DNA plasmid delivery, our 0.6 and 1.2-mm-long microneedles with ~ 5 μm tips and 750 μm pitch, can penetrate the outer skin to reduce the contact impedance that achieves effective electroporation within tens of volts and without obvious injury.