Every year more than 500,000 U.S. residents undergo coronary-artery bypass surgery. Soon, thanks to Rice University associate professor of bioengineering Jennifer West, that procedure may be less painful. To create a bypass, doctors must harvest a blood vessel- usually from the patient’s leg. West, however is growing vessels in the lab. She starts by synthesizing polymers that contain biological signaling molecules, the same molecules that guide tissue growth in the body. She molds the synthetic polymers into a blood-vessel-shaped template that is then seeded with three different types of live cells; by optimizing the polymers for different regions of the template, she can recreate the architecture of a natural vessel. The signaling molecules direct the cells to form new tissue, and the polymer support degrades in response. Human tests of the technology could start in five to 10 years, West says. Meanwhile, other heart patients might benefit from another West innovation: a polymer that could be used to coat an artery after angioplasty to prevent new blockages from forming. And West’s innovations address more than heart disease. She cofounded Nanospectra Biosciences in Houston to develop a cancer therapy based on gold nanoparticles that destroy tumor cells.