3D Printers and Human Tissue
A
Although the technology for it has been around since the 1980s, it was only after 2010 that 3D printers became widely available commercially. The ability to make three-dimensional solid objects of almost any shape from a digital model has since taken off exponentially, with virtually every sector eager to find ways to apply this technological breakthrough. While most people expect that 3D printing would be useful in fields such as architecture, construction, industrial design, and aerospace, few consider the implications of this technology for biotechnology and medical research. But, in fact, the ability to create live human tissue replacement, and potentially even whole organs, is what has the medical science community so excited.
B
For the last 20 years, even before 3D printers hit the market, medical researchers have been experimenting with ways to use the technology to create three-dimensional biological structures for medical purposes. To understand stand how this is possible, it’s important to grasp how 3D printing works. The first step is to create a 3D image of the desired item using a computer-assisted design software program. The program then slices the object into hundreds or even thousands of horizontal layers that become the blueprint for the printing stage. The actual printing is achieved using an additive process, which means that successive layers of liquid, powder, paper or other material are laid down from the bottom up to build the model from a series of cross sections. These layers are then joined or fused to produce the final shape.
C
As soon as this technology came out, medical researchers thought, why not layer living cells just as you do any other material, and thereby engineer biological structures such as tissue? Since the mid-2000s, biotechnology firms and academic researchers have taken up this question. In only a few years, they have achieved significant success in producing human tissues that preserve cell function and viability. The types of human tissue that have thus far been successfully produced include bits of lung, kidney and heart muscles, as well as valves, splints, and even a human ear. Experiments transplanting these tissues into laboratory animals have produced overwhelmingly positive results. Surgeons have also been able to implant some of this bioprinted tissue—including skin, cartilage and muscle—into human patients, in one case saving a 3-year-old girl by keeping her airway open with a stint.
D
But the ultimate goal is to be able to create whole organ replacements using a patient’s own cells, reducing the risk of rejection that is so common with donor organs or artificial hearts. Developing complex organs is a major challenge, especially in regards to creating a structure with enough oxygen to survive until it can integrate with the body. In addition, even if you can develop the organ with the right structure, getting all of the cells to work together as they do in a natural organ is a formidable task. However, leading biotechnology experts are optimistic that such a goal is achievable in the near future, and that a “bioficial organ”—an organ made with a blend of natural and artificial elements—could be tested in a human within the next decade.
E
The primary purpose of doing so is, of course, to provide replacement organs for patients desperately in need of transplants. With more than 80,000 people on kidney transplants lists in the UK alone, the pressure to advance this technology is high. But asides from organ replacement, bioficial tissue can also be used for medical research and drug development. For example, scientists have found that bioprinted slivers of liver, although quit tiny, respond to drugs in very similar ways to a full-grown human liver. This has allowed researchers to test the toxicity of new drugs before approving expensive clinical trials with patients. The potential to save billions of dollars in clinical research each year has caught the attention of investors and funders.