Silk-based medical devices promote bone regrowth

Biomedical engineers at Tufts University in Maryland have devised a method for incorporating RNA-based therapeutics into surgical devices such as screws, rods and plates used to support healing bone fractures that speed up the regeneration of healthy bone. The devices are derived from silk, and the therapeutic agents are incorporated into the structure during their manufacture.

One advantage of using devices made from silk is that they are absorbed into the body, leaving just healthy bone behind as part of the healing process. The team, comprising Eric James, David Kaplan, Emily Van Doran, and Chunmai Lee, coated the surface of the devices with a micro-RNA agent which suppresses the action of proteins that slow down bone growth. Known as anti-sense miR-214, the healing agent should not be regarded as a genetic therapy, they explain, because it is such a small fragment that, although it works by penetrating the cell wall, it does not need to enter the cell nucleus and change the function of that cell’s DNA for its activity.