Twelve years ago, Wake Forest University's Institute for Regenerative Medicine, based in Winston-Salem, N.C., was the first group in the world to successfully implant a lab-grown bladder in a human. The same group announced in 2011 that it had grown a miniature liver, one inch in diameter, that functions, at least in the lab, as a human liver does.
So if organs can simply be grown in a lab, what's the fuss about 3D printing? Why not just get some cells in a Petri dish and pour in the cellular Miracle Grow?
Well, for perspective, the first kidney transplant from a living donor happened a mere 59 years ago, with several unsuccessful attempts preceding it. Growing a complex organ from stem cells and then making it function normally when hooked up to the human body will take time to get right. As the process is perfected, it will need to become continuously faster and more streamlined, because organ-transplant patients' time is limited. As Wake Forest's website puts it, "One challenge is to learn to grow billions of liver cells at one time in order to engineer livers large enough for patients." This is where bioprinting comes in.
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Atala, a researcher at the forefront of tissue-engineering technology, explains the painstaking process of the 2001 bladder breakthrough. "The bladder scaffold was fashioned by hand and the cells were applied by hand with a pipette," he tells the Bohemian. "With 3D printing, our goal is to make this process more precise. The scaffold would be printed using data from a patient's medical scans, and the computer controls the placement of cells. This allows for the exact placement of multiple cell types."
In other words, 3D printing makes an exact replica of a patient's own organ using his or her own cells. It does this fast, with no breaks, and with precise execution—like an assembly line for organs.
DRUGS & SURGERY
As the only publicly traded bioprinting company, San Diego–based Organovo has been making the most headlines in the industry. In April, Organovo announced it had printed a 1mm-thick functioning human liver, which had lived for almost a week. "It grew to about twice as thick as we would have expected," says spokesman Mike Renard in a phone interview with the Bohemian. By printing cells that grew into blood vessels, in addition to ones that make the liver function, "it allowed nutrients to go deeper in than would normally be the case," says Renard.
Though this is still far away from being implantable in a human, it's a big step in another facet of bioprinting: drug research.
Organovo's focus right now is making living tissue for use in pharmaceutical research, specifically cancer drugs. Only about one in 5,000 drugs currently in development will make it to market, with an average cost of
$1.2 billion per product and 12 years in development. If drug companies were able to test prototypes on specific, living human tissue, time and money needed to produce effective pharmaceuticals would be reduced significantly. "Many drugs fail only after they get into humans," says Renard. The ability to work on living, human tissue "helps make good decisions about safety and efficacy early in the process."
TeVido BioDevices, in Austin, Texas, is focused on another area of tissue structures: reconstructive surgery. Led by Dr. Thomas Boland, University of Texas in El Paso faculty member and one of the founding fathers of bioprinting technology, the company is hoping its work on breast tissue will pay off.
Recovery from lumpectomy or mastectomy surgery is often a painful process, physically and emotionally. As far as reconstructive surgery, "right now, there's really no good option," says Scott Collins, TeVido's vice president of research and development. The best scenario may include a tissue graft from a patient's belly, but that doesn't allow nipple or areola reconstruction, and it doesn't react or feel the same. TeVido is working on a process in which living tissue from a patient's own cells could be printed to exact size and shape specifications within an hour, taking on the body's natural functions after implantation. "The real work is being done by the cells," says Collins. "We just have to put them in the right environment so they do what we want them to do."
This is good news for breast cancer patients and those with the risk-inherent BRCA mutation, which was brought to the wider public eye when actress Angelina Jolie chose to have a preventative double mastectomy after discovering she had an 87 percent chance of developing breast cancer. It's also good news for plastic surgeons: what can be done to replace what's been removed can also be done to add to what's perceived to be lacking.
TeVido was awarded a $150,000 federal grant from Small Business Innovation Research this year. It reads, "The results of this research will help the field move towards larger, clinically relevant tissues and potentially whole organs. The commercial impacts of this research will be the availability of an autologous option for women in the lucrative $10 billion market for breast augmentation."