I have spent the last 7 years studying, designing, and building machines. With proper care, machines can “live forever”. Perhaps humans can too.
Humans and machines physically deteriorate throughout their lifetimes. When a mechanical component deteriorates beyond repair it is replaced. Amazingly, we have the ability to replace some human components too, but the replacements we currently use are not perfect and are not abundant. In 2016, over 7,000 people died in the United States while waiting for a lifesaving organ transplant. There are currently 115,000 people on the organ transplantation waitlist, but only 13,000 donations have been made this year to date.  Tissue engineering promises to eliminate the need to wait for a limited supply of donor tissues, solving the organ transplantation crisis and extending human life expectancy. This technology will allow us to develop human tissue, in vitro, on demand, and using a host’s own cells, reducing the risk of immune rejection. 
Organovo was founded in 2007 around the research of Dr. Thomas Boland at Clemson University and Dr. Gabor Forgacs at the University of Missouri–Columbia.  Dr. Forgacs and his partners built NovoGenTM, the first 3D bioprinter that enabled precise placement of cellular aggregate – also called bio-ink – to form simple tissue structures.  Though the printing of smaller tissues in the form of tubes, patches, and organoids is possible today, the printing of whole replacement organs remains a medium to long term goal of Organovo.  The science is still years away.
In the short term, the company is solving another momentous problem for the pharmaceutical industry. Organovo’s 3D printed tissue provides researchers the opportunity to test drugs on a functional human model before ever administering the drug to a living person. Prior to Organovo’s breakthrough innovation, pharmaceutical companies could test on animals or human cells in a 2D architecture before moving to clinical trials. Neither of the prior models function in the same way as human cells in a 3D architecture, resulting in high failure rates of drugs during clinical trials that had been successful in preclinical testing.  A 2016 study reported the cost of clinical trials to be between US$20 million and US$80 million.  Another 2014 study reported that only 10% of drugs pass clinical trials and make it to market.  Organovo’s 3D printed tissue is positioned to increase the success rate of drugs in clinical trials, saving pharmaceutical companies millions of dollars and months of time in research and development.
With so much potential in the short and long term, what is there not to like about Organovo and the future of 3D bioprinting? It seems likely that only wealthy subgroups of developed countries will be able to afford the technology in its early days. It’s possible that a tiered system of organ replacement will emerge with those who can afford to pay for 3D printed organs living longer and enjoying a significantly higher quality of life. Others will have no choice but to continue to wait until a human organ donor becomes available and then have to rely on medication for the rest of their lives to prevent rejection of the transplanted organ.  Further, a “designer babies” problem may arise. Individuals may try to enhance themselves with 3D bioprinting if they can get an advantage. 
Some legal authorities suggest that 3D bioprinting does not fit within the current frameworks for regulation on medicine or conventional 3D printing. This could lead to new forms of exploitation such as a new black market in 3D bioprinted organs.  Given the severity of the ethical and legal concerns surrounding 3D bioprinting, I suggest that Organovo work proactively with the proper medical and legal authorities in the short and medium terms to ensure a positive future for their technology.
While 3D bioprinting of whole organs will likely begin with the kidney, liver and heart, the ultimate key to extending human longevity is the brain. Projecting into a future where brain transplantation using 3D bioprinted brains is physically possible, how do we maintain brain-body history and proper brain-body function?  If we can develop the ability to repair or replace all components of the human body, including the brain, what would be the extent of human lifespan? Can we live forever?
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