Cross-shaped RNA carries drugs to cells

By creating X-shaped fragments of RNA, a research team at the University of Kentucky has created a stable nanoparticle that can carry four active agents, one on each arm. These could have potential in delivering diagnostics and therapeutics to treat viral infections. They could also target cancer without affecting healthy tissues.

Historically, RNA particles have been rather unstable. But the researchers have managed to stabilize these, both on the bench and in animals, so that they can resist both the temperatures in the body, and naturally occurring RNase enzymes in the blood.

Each "arm" of the RNA molecule can carry a small interfering RNA or microRNA (scraps of RNA that control gene expression), a ribozyme (folded RNA that acts as an enzyme) or an aptamer (a piece of genetic material that binds to a target, such as a cancer cell).

In mice, the nanoparticles bound to tumors and stayed there for more than 8 hours, with no traces in the liver, lungs or other tissues. According to the researchers, the more of these "functional modules" the particle carries, the more effect the molecule has. The results were published in NanoToday.

"A major problem with cancer treatments is the ability to more directly and specifically deliver anti-cancer drugs to cancer metastases," said Mark Evers, of the UK Markey Cancer Center, in a statement. "Using the nanotechnology approach that Peixuan Guo and his group have devised may allow us to more effectively treat cancer metastasis with fewer side effects compared to current chemotherapy."

- read the press release
- see the abstract