As osteoarthritis wears away at joint cartilage, there are no available drugs to stop the process. Steroid injections help to reduce inflammation in the area, but they get washed away by the body in a short amount of time and the process continues. Researchers at Washington University in St. Louis have now created nanoparticles that carry an engineered version of a protein called melittin bound to an siRNA (small interfering RNA) molecule. The nanoparticles themselves are an order of magnitude smaller than red blood cells, allowing them to penetrate through cartilage and get inside of cells that are undergoing inflammation. The siRNA molecules interfere with the natural process of inflammation, essentially halting it and preventing further injury.
These loaded nanoparticles were injected into the cartilage of mice just after an injury. They started having an effect within 24 hours and continued working for weeks thereafter. While animal models post injury are a pretty good indicator of future success, these nanoparticles will need to prove their benefits over a longer term and on models with osteoarthritis that are not necessarily injured. There’s still a long ways to go before we see this technology being used in humans.
Study in Proceedings of the National Academy of Sciences: Suppression of NF-κB activity via nanoparticle-based siRNA delivery alters early cartilage responses to injury…