Gene silencing technology, otherwise known as RNA interference (RNAi), made a big splash when it was discovered a dozen years ago because of its potential to "silence" genes that cause cancers. The approach takes strands of genetic code, programs them to find the gene responsible for a deadly condition, and then shuts it up. Many forms of cancer are caused by genes gone haywire. The ability to silence and regulate problem genes selectively through short interfering RNA (siRNA) could provide a means to treat a wide range of human diseases. It has taken the intervening 12 years to develop RNAi therapeutics and to find a way of effectively delivering it to the right spot. And it's still slow going. Some drug companies have thrown up their hands in frustration at the challenges.
Nevertheless, successes are still being reported in the lab, and much of it has to do with nanoparticles engineered to do the job. "Delivery is the key element of this field," Dicerna CEO Doug Fambrough told Xconomy earlier this year, adding that one reason his company is attracting investment is because they're linking their drugs to other molecules that deliver them to cells. Article
Researchers at the University of Texas MD Anderson Cancer Center and the University of North Texas Health Science Center believe they've found just the right delivery molecule in a batch of synthetic high-density lipoprotein (HDL) that they concocted.
Anil Sood and colleagues created synthetic HDL nanoparticles, loaded them with siRNA to silence cancer-causing genes and injected them into mice with ovarian cancer. The recipe seemed to work, as the ovarian cancers were either shrunk or destroyed.
Sood said that previous tries at delivering siRNA with liposomes and other nanoparticles have not been greatly successful because of toxicity and other concerns. "HDL is completely biocompatible and is a safety improvement over other types of nanoparticles." Article