Right now in the United States, nearly 120,000 people are waiting for an organ transplant. Among them, 95,000 are waiting for a kidney, 15,000 need a liver, and 3,000 must get a heart. Depending on age, blood type, and ethnicity, these patients will wait anywhere from a few months to a few years for an organ--and some won't get it in time.
Keith Murphy, CEO of the biomedical engineering start-up Organovo, thinks there's a better answer: 3-D bioprinting. Doctors could create an organ in a lab precisely when it's needed.
"Surgeons are very limited by what they have available today," Murphy says. "If you can give them tissue to order, you can multiply, exponentially, the types of surgery that we can even envision doing. And if you could do it with a patient's own cells, surgeons could go places they haven't gone before."
They're printing what?
Professor Gabor Forgacs and his team at the University of Missouri, Columbia, developed Organovo's technology and founded the company in 2007. Since then, Organovo has made startling progress in the tissue engineering field. Unlike other tissue engineering methods, which make use of polymers--biomaterials that create structure and bond to cells--Organovo's NovoGen MMX Bioprinter uses human cells and shapes them into real tissue.
It may sound like science fiction, but it's all possible through a carefully controlled engineering feat.
As with any 3-D printer, lasers guide the production of each tissue. But instead of ink or plastic molding, the printer ejects a liquid filled with thousands of human cells. The process repeats, creating multiple "stacks" of cell layers, and a noninvasive gel holds the stacks together.
Then, cell biology kicks in: The cells assemble themselves as they would in a developing human body and mature, finally, into actual tissue.
Race to market
To be sure, Organovo isn't the only team working on 3-D bioprinting and tissue engineering. Academic institutions around the country, including Columbia, Cornell, and Wake Forest, have scores of researchers devoted to this very concept. But experts in the field point to Organovo's progress.
"If Organovo succeeds, it fundamentally alters the trajectory of health care. That's pretty hard to trump."
"These kinds of surgical tools have been lacking for a long time," says Dr. G. Sitta Sittampalam, a senior adviser and project manager at the National Institutes of Health and an expert in cell pharmacology and 3-D tissues. "This is very important."
To date, Organovo has used the technology to conduct research on liver cells and collaborated with both private enterprises and academic institutions (Pfizer and Harvard Medical School, for instance) to test tissue samples. In 2012, the company received multiple patents.
The biggest challenge in tissue engineering is thickness: Ultimately, Murphy says, going from tissues that are 1 millimeter thick to 5 millimeters thick will be harder than going from 5-millimeter tissue to building an organ. "We're still a couple years off," Murphy says, "but we're moving forward."