Growing synthetic windpipes, artificial skin and replacement blood vessels is now a reality, but scientists are now turning their attention to their ultimate goal: growing new human kidneys or hearts.
In June 2011, an Eritrean man entered an operating theatre with a cancer-ridden windpipe, but left with a brand new one. People had received windpipe transplants before, but Andemariam Teklesenbet Beyene’s was different. His was the first organ of its kind to be completely grown in a lab using the patient's own cells.
The practicalities are, as you can imagine, less straightforward. Take the example I have already described. The process began with researchers taking 3D scans of Beyene’s windpipe, and from these scans Alexander Seifalian at University College London built an exact replica from a special polymer and a glass mould. This was flown to Sweden, where surgeon Paolo Macchiarini seeded this scaffold with stem cells taken from Beyene’s bone marrow. These stem cells, which can develop into every type of cell in the body, soaked into the structure and slowly recreated the man’s own tissues. The team at Stockholm’s Karolinska University Hospital incubated the growing windpipe in a bioreactor – a vat designed to mimic the conditions inside the human body.
Two days later, Macchiarini transplanted the windpipe during a 12-hour operation, and after a month, Beyene was discharged from the hospital, cancer-free. A few months later, the team repeated the trick with another cancer patient, an American man called Christopher Lyles.
“A good way to think about it is that there are four levels of complexity,” says Anthony Atala from the Wake Forest Institute for Regenerative Medicine, one of the leaders of the field. The first level includes flat organs like skin, which comprise just a few types of cells. Next up are tubes, like windpipes or blood vessels, with slightly more complex shapes and more varied collections of cells. The third level includes hollow sac-like organs, like the bladder or stomach. Unlike the tubes, which just act as pipes for fluid, these organs have to perform on demand – secreting, expanding or filtering as the situation arises.
Even after scientists successfully devise ways of growing organs, there are many logistical challenges to overcome before these isolated success stories can become everyday medical reality. “Can you manufacture them and grow them on large scales?” asks Robert Langer, a pioneer in the field. “Can you create them reproducibly? Can you preserve them [in the cold] so they have a reasonable shelf-life? There are a lot of very important engineering challenges to overcome.”
Source: http://www.bbc.com/future/story/20120223-will-we-ever-create-organs
Printing a human kidney
Surgeon Anthony Atala demonstrates an early-stage experiment that could someday solve the organ-donor problem: a 3D printer that uses living cells to output a transplantable kidney. Using similar technology, Dr. Atala's young patient Luke Massella received an engineered bladder 10 years ago.
Anthony Atala asks, "Can we grow organs instead of transplanting them?" His lab at the Wake Forest Institute for Regenerative Medicine is doing just that - engineering over 30 tissues and whole organs. Anthony Atala is the director of the Wake Forest Institute for Regenerative Medicine, where his work focuses on growing and regenerating tissues and organs. His team engineered the first lab-grown organ to be implanted into a human - a bladder - and is developing experimental fabrication technology that can "print" human tissue on demand.
In 2007, Atala and a team of Harvard University researchers showed that stem cells can be harvested from the amniotic fluid of pregnant women. This and other breakthroughs in the development of smart bio-materials and tissue fabrication technology promises to revolutionize the practice of medicine.
Source: http://www.bbc.com/future/story/20120621-printing-a-human-kidney
