Slice of human dermal tissue is positioned between electrodes connected to a generator

Apparatus in which a small slice of human dermal tissue was placed between electrodes connected to a generator. This tissue was a dermal substitute engineered from cells taken during a skin biopsy. The generator transmitted electrical impulses with known parameters to induce a transitory permeabilisation of the membranes of the tissue cells and enable a GFP-expressing plasmid (Green Fluorescent Protein a protein that emits fluorescent green light) to penetrate the cells. After 24 or 48 hours, the tissue was examined by multiphoton microscope in order to locate and quantify the amount of GFP-expressing cells. This experiment enabled us to obtain in vitro rates of transfection comparable to those obtained in vivo. It thus proved possible to create a substitute for human skin in vitro, i.e. a dermal model that can be used in the laboratory. This will allow us to limit the number of in vivo tests on animal models.