Nonviral gene delivery

Gene and RNA interference therapies are promising cures for intractable renal failure. However, low delivery efficiency of the therapeutic nucleic acid into the nucleus of the target cell is a significant obstacle in the clinical application of nonviral gene therapy. Various mechanical techniques (hydrodynamic injection, electroporation and ultrasound-microbubble) and topically applied preparations (HVJ liposome and cationic liposome/polymer), which introduce transgenes into specific renal compartments depending on the administration route, have been reported. Additional improvements in renal application of nonviral gene vectors must address the important issue of how to control intracellular trafficking. Therefore, novel vectors based on the 'programmed packaging' concept are desirable in which all functional devices are integrated into a single system so that each function occurs at the appropriate time and correct place. In parallel with development of the carrier, quantitative evaluation of intracellular trafficking is essential to determine the efficacy of the modified devices in the cellular environment. In particular, comparison of the intracellular trafficking of the engineered devices with that of viruses (i.e. adenovirus) is useful in identifying the rate-limiting intracellular processes of the vectors during development.