The findings are published in the April 27 issue of the Proceedings of the National Academy of Sciences. The researchers caution, however, that the effect the PEI has on the cell needs to be known before this method could be used to treat disease. Once inside the cell, rather than being broken down and used by the cell's machinery, the complexes move into the nucleus, where the desired gene is turned on. The researchers labeled both the DNA and the PEI separately in different colors, to verify that the complex gets into the nucleus intact.
More research needs to be done to determine the mechanism.
Gene therapy has traditionally taken advantage of a virus's ability to inject its DNA into cells, but with the viral agents come risks, such as an immune response. Researchers have wanted to find safer, nonviral agents to gain access to cells. Both viral methods and nonviral methods using liposomes, which can fuse with the cell membrane to gain entry, have been used in clinical trials to treat Cystic Fibrosis and several forms of cancer. In addition to Cystic Fibrosis and cancer, the technique is also promising for cardiovascular applications such as balloon angioplasty. During the procedure, gene therapy could be used to deliver genes aimed at slowing down the rapid proliferation of cells which causes scarring and a re-narrowing of the artery.