More than 100,000 people awaiting organ transplants in the United States alone; every day, 18 of them die. Not only are healthy organs rare, but donor and patient must also be closely matched, otherwise the patient's immune system could reject the transplant. A new type of solution is incubating in medical laboratories: “bioartificial” organs grown from the patient's own cells. Thirty people have already received lab-grown bladders, and other artificial organs are in the works. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get the original essay The bladder technique was developed by Anthony Atala of the Wake Forest Institute for Regenerative Medicine in Winston-Salem, North Carolina. Researchers take healthy cells from a patient's diseased bladder, multiply them extensively in Petri dishes, then apply them to a balloon-shaped support made partly of collagen, the protein found in cartilage. Muscle cells go on the outside, urothelial cells (which line the urinary tract) on the inside. “It’s like making a layer cake,” says Atala. “You layer the cells one layer at a time, spreading out these toppings.” The future bladder is then incubated at body temperature until the cells form functional tissue. The entire process takes six to eight weeks. Solid organs with many blood vessels, like the kidneys or liver, are more difficult to grow than hollow organs like the bladder. But Atala's group, which works on 22 organs and tissues, including ears, recently made a working piece of human liver. One of the tools they use is similar to an inkjet printer; it “prints” different cell types and organ scaffolding one layer at a time. Other laboratories are also entering the race to manufacture bio-artificial organs. A jaw sprouted at Columbia University and a lung at Yale. At the University of Minnesota, Doris Taylor made a beating rat heart, growing one rat's cells on a scaffold that she made from another's heart by removing her own cells. And at the University of Michigan, H. David Humes created an artificial kidney from cells seeded on a synthetic scaffold. This cell phone-sized kidney has successfully passed tests on sheep: it's not yet implantable, but it's portable, unlike a dialysis machine, and it does more than filter toxins from the blood . It also produces hormones and performs other kidney functions. It is not always possible to grow a copy of a patient's organ, for example when the original is too damaged by cancer. A solution for these patients could be a stem cell bank. Atala's team showed that stem cells can be harvested without harm to human embryos (and therefore without political controversy) from amniotic fluid present in the uterus. Researchers have induced these cells to become cells of the heart, liver and other organs. According to Atala, a bank of 100,000 stem cell samples would have enough genetic variety to match almost any patient. Surgeons would order organ growth as needed instead of waiting for cadavers that might not be a perfect match. A first: organs made to measure with the body's own cells. Keep in mind: this is just a sample. Get a personalized item now from our..