HOUSTON, May 5, 1999 -- A material used for years in common processes such as shampoo manufacturing, paper production and water filtration may one day bring DNA to a patient's cells by way of a safer, nonviral gene therapy method.

Poly(ethylenimine) (PEI), a polymer, has been used to successfully transfer genes into living cells. For the first time, researchers at Rice University and the University of Texas-Houston Health Science Center have tracked the path that this polymer--which acts as an artificial virus--and the DNA it carries take through the cell. They have shown that the complex ends up--intact--in the cell's nucleus, where the new DNA can be read and put to work.

Antonios (Tony) Mikos, Rice professor of bioengineering, W.T. (Terry) Godbey, Rice graduate student in biochemistry and cell biology, and Kenneth Wu, professor and director of the Division of Hematology and Vascular Biology Research Center at the UT-Houston Health Science Center, labeled PEI/DNA complexes, which are joined by their electrostatic attraction to each other, with fluorescent markers and followed the trail as they moved through the cell to the nucleus.

"This study improved our understanding of the transport of DNA into the nucleus and provided new knowledge for the design of better and safer nonviral carriers for gene delivery," Mikos said.

The findings are published in the April 27 issue of the Proceedings of the National Academy of Sciences.

"We ran into something a little bit surprising--that PEI actually delivers the DNA to the nucleus without separating from the DNA--they get in as intact structures," Godbey said. "That's important because there are other polycationic [positively charged] systems that exist and if our carrier gets into the nucleus, other polycationic carriers might also get in." The researchers caution, however, that the effect the PEI has on the cell needs to be known before this method coul
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Contact: Lia Unrau
unrau@rice.edu
713-831-4793
Rice University
5-May-1999