Imagine lying in a hospital room after a heart attack. The doctor comes in with a small device that looks like a tiny apple corer and says, “You need a valve replacement. I just need a bit of your skin, and we’ll have a new one printed for you in no time.”
The lab of Mayo Clinic’s Robert Simari, M.D., recently acquired one of the very few bioprinters in the nation, a device that lets us imagine such a scenario. Wednesday, Dr. Simari told an audience at the World Stem Cell Summit that his lab is working toward such a goal. Dr. Simari is the director of Mayo Clinic’s Center for Regenerative Medicine’s Valvular and Vascular Repair and Regeneration Program.
The technology of 3D printing, which layers, or prints, material to make a three-dimensional shape, has been around for decades, but until recently, it has been confined to the mechanical world. Today, scientists are applying the technology to print human tissue, using as its ink living human cells. Dr. Simari referred to an article in The Economist, which stated, “It is impossible to foresee the long term impact of 3D printing... But the technology is coming and it is likely to disrupt every field it touches.”
Dr. Simari is testing if bioprinting can complement his work of applying stem cells to build biological heart valves. He is completing studies using animal valve scaffolds populated with stem cells. However, the process of populating these scaffolds with cells and waiting for them to grow is difficult and time-consuming. The bioprinter might cut down on that time by printing the valve on demand, microscopic cell layer by microscopic cell layer.
Dr. Simari hopes his work will give better options for patients with heart valves. Today, two main options exist for the 200,000 patients who need valve replacements each year, but both have drawbacks. One is a bioprosthetic valve, which fails 20 percent of the time within first six years of placement. The other is a mechanical valve, which requires patients take anticoagulant drugs for the rest of their lives. For many patients, both options carry even larger risks. For instance, neither valve can grow, so when children need a new valve, they face a series of operations as they age, replacing larger valves to keep up with their growing hearts.
Dr. Simari believes that a heart valve tailored to each patient will help such patients.