The ability to bio-print tissues and organs could one day allow us to create custom body parts that could be used for transplants. New research has brought that possibility one step closer to reality. Scientists have bio-printed artificial vascular networks that mimic the body's circulatory system.
Bio-printing continues to move forward. Recent advancements have included the development of a new technique that creates thicker, healthier tissue and a means of printing stem cell structures for treating osteoarthritis.
Being able to bio-print an artificial vascular network would give us the ability to keep tissue and organs alive where previously it would not have been possible. The body's vascular network enables it to transport blood and, therefore, oxygen and nutrients, to tissues and organs. It also provides a means of transporting waste materials away from tissues and organs.
"Cells die without an adequate blood supply because blood supplies oxygen that's necessary for cells to grow and perform a range of functions in the body," says lead author of the study, Dr. Luiz Bertassoni. "To illustrate the scale and complexity of the bio-engineering challenge we face, consider that every cell in the body is just a hair's width from a supply of oxygenated blood. Replicating the complexity of these networks has been a stumbling block preventing tissue engineering from becoming a real world clinical application."
In order to solve this problem, the researchers created a framework of tiny interconnected fibers to serve as a mold, using a bio-printer. The structure was then covered with a "cell-rich protein-based material" and solidified using light. The fibers were removed to leave a "network of tiny channels coated with human endothelial cells, which self-organized to form stable blood capillaries in less than a week."
According to the University of Sydney study, the technique demonstrated better cell survival, differentiation and proliferation compared to cells that received no nutrient supply. In addition, Bertassoni says that it provides the ability to create large, life-supporting three-dimensional, micro-vascular channels quickly and with the precision required for application to different individuals.
"While recreating little parts of tissues in the lab is something that we have already been able to do, the possibility of printing three-dimensional tissues with functional blood capillaries in the blink of an eye is a game changer," he says.
Bertassoni explains that the ultimate aim of the research is for patients to be able to walk into a hospital and have a full organ printed with all the cells, proteins and blood vessels in the right place.
"We are still far away from that, but our research is addressing exactly that," he says. "Our finding is an important new step towards achieving these goals. At the moment, we are pretty much printing 'prototypes' that, as we improve, will eventually be used to change the way we treat patients worldwide."
Source: The University of Sydney