A team of bioengineers at Rice University and surgeons at the University of Pennsylvania have created an implant with an intricate network of blood vessels that point toward a future of growing replacement tissues and organs for transplantation by using sugar, silicone and a 3-D printer. The research might provide a method to overcome one of the biggest challenges in regenerative medicine: How to deliver oxygen and nutrients to all cells in an artificial organ or tissue implant that takes days or weeks to grow in the lab prior to surgery.
The new study was undertaken by a research team led by Jordan Miller, assistant professor of bioengineering at Rice, and Pavan Atluri, assistant professor of surgery at Penn. The study showed that blood flowed normally through test constructs that were surgically connected to native blood vessels. Miller said one of the hurdles of engineering large artificial tissues, such as livers or kidneys, is keeping the cells inside them alive. Tissue engineers have typically relied on the body’s own ability to grow blood vessels, for example, by implanting engineered tissue scaffolds inside the body and waiting for blood vessels from nearby tissues to spread to the engineered constructs. Miller said that process can take weeks, and cells deep inside the constructs often starve or die from lack of oxygen before they’re reached by the slow-approaching blood vessels. Using Doppler imaging technology, the team observed and measured blood flow through the construct and found that it withstood physiologic pressures and remained open and unobstructed for up to three hours.