A highly efficient electroporation method for the transfection of endothelial cells

Several approaches have been described for improving transfection efficiencies of endothelial cells but the general observations have indicated that yields of transfected endothelial cells are low, irrespective of the techniques used. Here we describe a transfection procedure performed by means of electroporation, with efficiencies up to 85%, by optimizing several parameters such as the electroporation buffer, number of cells, voltage, capacitance and pulse length. The protocol was applied to three endothelial cell types (HUVECs, HUAECs and HMEC-1) commonly used in 'in vitro' angiogenic assays. We did not observe functional impairment between transfected and non-transfected cells in their adhesion to different components of the extracellular matrix, migration, or the development of capillary-like structures. Our experiments show that this electroporation procedure does not alter the physiology of endothelial cells and can be applied to functional studies, as exemplified by the successful transfection of the isoform 1 of calcipressin 1 (CALP1L).