Over 4000 patients in the United States are waiting for a heart transplant, while millions of others worldwide need hearts but are ineligible for the waitlist. In Germany, for instance, 300 heart transplants take place every year, while 700 people are waiting to receive a new heart, according to the German Center for Health Awareness.
US researchers used the 3D printing technique to create a heart prototype composed of two ventricles that contract regularly, and two valves. This prototype proves that this technique can be used in the future to print body organs, they said.
Adam Feinberg, senior researchers at the Carnegie Mellon University in Pittsburgh, Pennsylvania, said: "What we've shown is that we can print pieces of the heart out of cells and collagen into parts that truly function, like a heart valve or a small beating ventricle."
"We were able to accurately reproduce patient-specific anatomical structure," he explained noting that the method is not yet ready for the practical use, the German News Agency reported.
For his part, Andrew Hudson, co-author on the paper, said: "Collagen is an extremely desirable biomaterial to 3D print with because it makes up literally every single tissue in your body. What makes it so hard to 3D print, however, is that it starts out as a fluid, and forms a puddle on your build platform. So we've developed a technique that prevents it from deforming."
In the new method dubbed "FRESH", the researchers used a 3D printer that allows collagen to be deposited layer-by-layer within a support bath of gel, giving the collagen a chance to solidify in place. Once the printing process ends, the support gel can be easily melted away by heating the gel from room temperature to body temperature to preserve the final structure without damages, explained the researchers in their study published in the current issue of the Science journal.
The printing purity is estimated at 20 micrometers (1 micrometer = 1000 millimeter), 10 times thinner than the method used four years ago for the same purpose. According to the researchers, the ultrathin porous structure allows cells and capillaries to grow inside it.