Gene therapy: the state of the art and future directions

Gene therapy, because of its aim to eradicate the causes rather than the symptoms of diseases, is believed by many to be the therapy of the future. The problems of developing clinically viable gene therapeutic approaches and designing safe and efficient gene delivery reagents are inseparable: shortcomings in one are going to affect adversely the success of the other. It is generally accepted that the major impediment to the successful application of gene therapy for the treatment of a range of dis-eases is not a paucity of therapeutic genes, but the lack of efficient non-toxic gene delivery systems. Transfection vectors com-monly used in gene therapy are mainly of two types: viral and non-viral. Non-viral gene delivery is currently the subject of increasing attention because of its relative safety and its simplicity of use; however, its use is still far from being ideal due to its comparatively low efficiency. The purpose of this review is to give an overview of the current knowledge concerning the assembly of lipoplexes and the trafficking of lipoplexes into cells, as well as to underscore the advantages and disadvantages of lipidic gene carriers among non-viral gene delivery systems.