Using specialized nanoparticles, MIT engineers have developed a way to turn off specific genes in cells of the bone marrow, which play an important role in producing blood cells. These particles could be tailored to help treat heart disease or to boost the yield of stem cells in patients who need stem cell transplants, the researchers say. This type of genetic therapy, known as RNA interference, is usually difficult to target to organs other than the liver, where nanoparticles would tend to accumulate. The MIT researchers were able to modify…