ABSTRACT
With the progress of molecular biology and genetics, particularly with the identi cation, sequencing, and characterization of an increasing number of pathogenic genes, genetic therapy has appeared as a therapeutic modality with a tremendous potential impact on the quality of human life. In general, genetic therapy consists of delivering nucleic acids to the interior of speci c target cells in the organism (Rayburn et al., 2005). In the more traditional approach of gene therapy, the gene of interest is inserted into the genetic code to restore or correct some functions in the cell. In a different approach, ribonucleic acid (RNA) silencing molecules are delivered to the cell cytoplasm and produce, on the basis of different mechanisms not yet completely understood, the inhibition of the expression of pathogenic genes. In both cases, however, a proper vector transporting the therapeutic nucleic acids through the cell membrane and delivering the genetic material to the cytoplasm must be employed.
