Researchers at the National University of Singapore have developed a method for delivering the polypeptide antibiotic actinomycin D with modified, self-assembled DNA nanopyramid against bacteria such as E. coli and Staphylococcus aureus, the bug that causes staph infections.
When the antibiotic was delivered via the nanopyramids, it killed 65% of Staphylococcus and 48% of E. coli, compared to 42% and 14% respectively when used alone, according to Nevada's Liberty Voice. In addition, the researchers used red-emissive glutathione-protected gold nanoclusters to track whether the DNA pyramids entered the cell.
Much like some other recent developments in drug delivery, this one makes use of a technique called DNA origami, which uses the genetic substance not for its ability to carry information, but to form itself into easily manipulated shapes based on an engineer's needs. These can be used to develop simple cagelike structures or highly complex nanorobots with the ability to perform certain functions in the body.
DNA Origami is an important innovation in drug delivery, as it allows for precise, robotic methods to transport and release drugs at targeted locations. For example, earlier this year researchers at Harvard University's Wyss Institute developed "smart" nanoparticles out of DNA that acted like a virus to bypass the immune system's defenses and deliver drugs to a tumor. Also a team at Italy's University of Udine have developed small nanorobots with a "flap" designed to open and release compounds with unprecedented precision.
The latest breakthrough described in journal ACS Applied Materials and Interface comes at a time of growing concern about the rise of antibacterial resistant strains and a lack of new antibiotics. The director of the Centers for Disease Control and prevention Tom Frieden said during a recent speech that "we talk about pre-antibiotic era and the antibiotic era. If we're not careful, we will soon be in a post-antibiotic era. And in fact, for some patients and some pathogens, we're already there."
Special Report: The year in nanotech drug delivery - 'DNA origami' shapes vehicles to be used for delivery