A wide range of chemical agents are already known to be able to form a complex of 1,4-DHP with DNA and deliver it into the recipient's cells. These agents are much easier to produce on a large scale than viruses and do not usually cause an immune response. However they are not so effective at introducing the DNA as the viral carriers.
Seeking the best of both worlds
The challenge facing the partners in the EUREKA project was to combine the effectiveness of the viral vectors with the production advantages and lack of immune response shown by chemical agents. Scientists at the Latvian Institute of Organic Synthesis and the University of Kuopio in Finland had discovered new groups of possible DNA transfer agents: 1,4-DHP derivatives. These compounds were found to be more effective in gene transfer than two widely-used standard gene delivery agents (known as DOTAP and PEI 25) and the discovery was covered by a patent. This finding offered the exciting prospect of better efficiency from a non-viral carrier.
Professor Arto Urtti of Helsinki University (formerly from Kuopio) explains: "When these compounds are in solution and DNA is added, they bind together. The large, loose DNA molecule collapses and tiny particles of about 10-50nm in diameter are formed, composed of both DNA and carrier. When you present this to the cells, the nanoparticles bind to the cell surface, which folds inwards to form a vesicle within the cell. The particles then escape from the vesicle, releasing the DNA."
Researchers at Helsinki University found that out of all the compounds tested, the most effective were those which succeeded in transferring DNA into the nucleus. The mechanism by which the DNA enters the nucleus is not yet c
|Contact: Piotr Pogorzelski|