Notwithstanding, knowing that the complexation with dendrimers probably did not fully protect siRNA from nucleolytic degradation, we proceeded to evaluate the transfection efficiency of control FITC-labeled siRNA complexed with both dendrimers at a lower, less cytotoxic concentration (3.5 µM and 10 µM for (CuSO4)18@DAB-dendr-(Pyrr)64 and (ZnCl2)22@DAB-dendr-(Pyrr)64, respectively). A commercially used carrier of the genetic material lipofectamine was used as a control.