Freeze-dried nanoparticles produced by Johns Hopkins biomedical engineers might be a better, safer alternative to virus-mediated gene therapy, according to researchers writing in the August issue of Biomaterials. Science Daily has the story about one solution to the safety problems associated with use of viruses to deliver genes.
"Most nonviral gene therapy methods have very low efficacy," Jordan Green, an assistant professor of biomedical engineering at Johns Hopkins, tells Science Daily. "Nanoparticle-based gene therapy has the potential to be both safer and more effective than conventional chemical therapies for the treatment of cancer."
First, the team played around with combinations of molecules to form different polymers. Then they mixed in a DNA that encodes a glowing protein and watched the DNA combined with the polymers to form nanoparticles. Next, the nanoparticle mix was introduced to human brain tumor cells. Forty-eight hours later, they took a look at which cells were glowing, which indicated which ones took in the nanoparticles. One formulation of poly(beta-amino ester) nanoparticles did particularly well at getting into both glioblastoma and brain tumor stem cells. Those are the nanoparticles that the researchers decided to freeze-dry and store at different temperatures for different lengths of time. They found that six months was too long and three months was just the right amount of time with no change in effectiveness.
Also, Science Daily reports, the team found that some nanoparticles enjoyed the company of brain tumor cells over healthy brain cells. "I could imagine particles based on this technology being used in conjunction with, and even instead of brain surgery," Johns Hopkins' Alfredo Quinones-Hinojosa tells Science Daily. "I envision that one day, as we understand the etiology and progression of brain cancer, we will be able to use these nanoparticles even before doing surgery--how nice would that be? Imagine avoiding brain surgery all together."