Who knew that $40 and a cotton candy machine from Target could possibly lead to a critical advance in tissue transplant technology? But that's just what happened when a mechanical engineer from Vanderbilt University used his powers of observation during graduate school.
Transplantation using organs manufactured in a lab are a step closer to becoming a not so distant reality thanks to this cotton candy technology. One of the major challenges in creating viable tissues for transplantation, or to regenerate or replace those that have been damaged in the host, has been creating a vascular supply to provide tissues with the nourishment they need while disposing of the waste products they don t.
Capillaries are fine branching blood vessels that provide blood supply to tissues and carry waste products away. It seems that research from the lab of Leon Bellan, assistant professor of mechanical engineering at Vanderbilt University in Nashville, TN, could not come at a more opportune time. Dr. Bellan has been working for several years on using the cotton candy machine to spin out capillary-like networks of tiny threads that resemble very closely patterns formed by capillaries, in size, density and complexity.
Recently published in the journal Advanced Healthcare Materials, Dr. Bellan and his colleagues discuss how their unorthodox technique has enabled them to keep living cells viable and functional for over a week this is much longer than any previous attempt.
Some people in the field think this approach is a little crazy, states Dr. Bellan. But now we ve shown we can use this simple technique to make microfluidic networks that mimic the three-dimensional capillary system in the human body in a cell-friendly fashion. He went on to add, Generally, it s not that difficult to make two-dimensional networks, but adding the third dimension is much harder; with this approach, we can make our system as three-dimensional as we like.
Recently, I wrote about the technology of 3D bioprinting and how this technology is being used to construct tissues from living cells. According to Keith Murphy, the CEO of a 3D bioprinting company, Organovo, The biggest challenge to making larger tissues is keeping them alive. We could print a larger block of tissue but it wouldn t survive because the cells need oxygen and nutrients. You need a full vascular system like the one that exists in the body to keep those cells alive. Again, the findings from Dr. Bellan s lab will be critical in addressing that challenge.
Dr. Bellan s team is using hydrogels as the scaffold for the support of cells in artificial organs a well-established method in the field of tissue engineering. Hydrogels are the preferred material as they very closely resemble the gel-like environment outside of cells, called the extracellular matrix (ECM). Another challenge in the creation of capillary networks embedded in a hydrogel structure is creating channels that allow free flow of fluids and nutrients like an actual capillary system. The scientists have overcome this roadblock using a technique they call the top-down approach.
This is certainly a ground-breaking effort in the challenge of making artificial organs to fulfill the imbalance of need and availability of life-saving organ transplants. It is also extraordinarily impressive to see how someone s creatively elegant vision fused science and art to potentially save lives.