Injury and disease can damage blood vessels. But Fan Yang, a Stanford professor of bioengineering and orthopedic surgery, has developed a way to persuade the body to repair them.
In her technique, stem cells are reprogrammed in the lab to produce a protein that stimulates the growth of blood vessels. Then the cells are injected into diseased areas of the body. Previous attempts to use this approach ran into problems because researchers relied on viruses to transport the protein-producing genetic instructions into the stem cells. Instead, Yang has made a biodegradable polymer that binds weakly to strands of DNA, clumping together to form nanoparticles that penetrate the stem cells and release the desired instructions. Because these polymers degrade naturally after use, the treatment is potentially safer than viral methods.
Yang believes that eventually the technology could be used to treat the damage caused by heart attacks, strokes, and diabetic ulcers. She’s now collaborating with Stanford surgeons and further improving the nanoparticles, but she estimates that it will be five to 10 years before the therapies move “from bench to bedside.” —Kristina Bjoran