The idea of creating artificial body organs is not new. It has been vastly developed in sci-fi literature, where the very process of creation was surrendered to the imagination of the author. Few people know that scientists have long been into this area and have reached some positive results.
Science Daily reports that Gabor Forgacs, a professor of physics in the MU College of Arts and Science, has been developing and perfecting the process of “printing” tissues, aiming at building human organs. In his recent study, Forgacs showed that creating tissue structures by means of printing maintain the properties of the composing cells, and the very process resembles the way living tissues are created in nature.
The researchers used bio-ink particles, or spheres with 10,000 to 40,000 cells, and “printed” them on sheets of special “bio-paper.” The spheres then began to fuse in the bio-paper into one structure, pretty much like drops of water stick together into a larger drop of water. The size and shape of the resulting structure can be controlled by removing bio-paper to stop the fusion.
Previously, there have been two obstacles that prevented printing tissues using large amounts of cells. First, it was necessary to find out how to get right cells to the right places locations within the tissue. Second, even with the right cells positioned in the right place, it was unclear how to make an organ start working.
In the course of the study, it turned out that both problems get solved almost automatically. As the tissue structure begins to form, the cells go through a natural process called “sorting,” which is nature’s way of determining where specific cells need to be. For example, an artery has three specific types of cells — endothelial cells, smooth muscle cells and fibroblast cells, each type needing to be in a specific location in the artery. As thousands and thousands of cells are added to the bio-paper under controlled conditions, the cells migrate automatically to their specific locations to make the structure form correctly.
The team also found that nature was the answer to the second question. In the study, scientists took cells from a chicken heart and used them to form bio-ink particles, which were then printed on to thick sheets. Heart cells must be synchronized for the heart to beat properly. When the bio-ink particles were first printed, the cells did not beat in unison, but as the cellular spheroids fused, the structure eventually started beating just as a heart does.