Scientists report today that artificial blood vessels made using a person’s own skin cells work well in patients receiving kidney dialysis. The new blood vessels mark the first vascular grafts to be derived entirely from a patient’s own tissues, which lowers the odds of a harmful immune reaction.

To speed the procedure of renal dialysis doctors typically implant a small blood vessel between a vein and an artery in the patient’s arm. Blood is then removed and reinserted through an intravenous line inserted into this bypass vessel. When possible, doctors typically harvest a piece of a vein from a patient to make this bypass, called a shunt. But over time, these shunts often fail, forcing doctors to use shunts made with plastics and other synthetic materials that can trigger immune reactions or blood-flow problems downstream.

They start by harvesting skin cells known as fibroblasts and growing these in a sheet. They then roll up the sheet and allow the cells to produce an interpenetrating mixture of structural support proteins, known as collagen and elastin. The trouble with fibroblasts is that they can transform into smooth muscle cells that can eventually clog the vessel. So McAllister’s team removed the fibroblasts, leaving behind just the protein scaffold. Then the researchers layered another sheet of fibroblasts on the outside of this scaffold, which is dense enough to prevent the cells from easily migrating to the inside of the engineered vessel. Finally, the team added a layer of the patient’s own endothelial cells, which promote smooth blood flow, on the inside of the vessel.