Organ transplants continue to be in high demand, with many people dying due to a lack of suitable organs. Due to the high demand, considerable shortages and the critical importance to human health, scientists are working with bio-printers to create viable 3D printed human organs with most research currently conducted on artificial heart, kidney, and liver structures.
According to the World Health Organization organ transplants are key to saving lives. Taking kidney transplants alone, the United Nations health agency notes that those transplants are carried out in 91 countries. In a typical year, some 66,000 kidney transplants, 21,000 liver transplants and 6000 heart transplants were performed globally. Although organ transplants often provide the only effective therapy for many otherwise fatal conditions there is invariably a shortage of suitable organs.
How might the technology work?
The main approach, being explored by many research groups, is:
3D printing of organs will begin with the layer-by-layer construction of a particular organ structure to form a cell scaffold.
This is followed by a process called cell seeding; here cells of interest are pipetted directly onto the scaffold structure.
Finally the process of integrating cells into the printable material itself begins.
The road ahead
There are several hurdles to be overcome before this vision becomes a reality. A considerable problem exists in terms of incorporating blood vessels into bioprinted tissue. All living tissue requires a blood supply; otherwise it would be impossible to deliver nutrients and remove waste from biological cells. In a new development, Rice University and Baylor College of Medicine scientists have developed a new technique that should make the fine capillaries needed for these functions possible.
With this the research team used endothelial cells and mixed them with the protein fibrin or with a semi-synthetic material termed gelatin methacrylate (GelMA). The latter material can effectively be 3D-printed.
Organ startups
Several startup companies are interested in developing 3D printed organ technology, such as biotech startup SiMMo3D which is evaluating what the latest developments can do now and in the future. Another company is Organovo which seeks to create functional human organs; the company already produces human tissues using a proprietary three-dimensional bioprinting technology. Taking a different direction is French 3D-printing startup Biomodex which aims to use regular additive manufacturing to create ultra-realistic organ replicas to help train surgeons.
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The research groups found, as Engadget reports, that when mixed with fibrin, the endothelial cells formed tubes. The same effect did not occur with GelMA initially.
However, when a stem cell found in bone marrow was added the endothelial cells were then able to form tubes in the GelMA. The fact that GelMA can be 3D printed marks a major step forwards in overcoming an obstacle in 3D printing functional human organs.
The new research is published in Biomaterials Science. The research is titled “Tubulogenesis of co-cultured human iPS-derived endothelial cells and human mesenchymal stem cells in fibrin and gelatin methacrylate gels.”
