Shape matters in DNA nanotherapy

Scientists at Johns Hopkins University and Northwestern University have discovered how to manipulate the shape of nanoparticles that transport DNA through the body and have demonstrated that the shape is important in how well they work in the treatment of diseases.

The study, “Plasmid Templated Shape Control of Condensed DNA-Block Copolymer Nanoparticles,” appeared in the October 12 online edition of the journal Advanced Materials. The study is noteworthy in that this gene therapy technique does not use a virus to carry DNA into cells, which has been shown to pose some health risks.

“These nanoparticles could become a safer and more effective delivery vehicle for gene therapy, targeting genetic diseases, cancer and other illnesses that can be treated with gene medicine,” said Hai-Quan Mao, an associate professor of materials science and engineering in Johns Hopkins’ Whiting School of Engineering.

The particle shapes (rods, worms, and spheres) used in the research were formed by packaging of DNA with polymers and exposure to various dilutions of an organic solvent. The nanoparticles contract into a certain shape after this, the genetic material being protected from immune cells. Degradation of the polymer only occurs within the target cells, releasing the DNA that can then serve as a template to produce functional proteins that combat disease.

Using computer simulations and theoretical model produced by the team from Northwestern University, the researchers were able to predict how to choose the nanoparticle components to obtain a certain shape. Furthermore, the researchers conducted animal tests, all using the same particle materials and the same DNA, changing only the shape of the nanoparticles. This was done to demonstrate the importance of particle shapes in the delivery of gene therapy.