The world is entering an age of bionic miracles. Consider eight people in Germany who suffered catastrophic liver failure, usually a death sentence. Early this year, these patients entered a clinical trial for a first-of-its-kind bionic liver -- a tiny pump, a chamber containing human liver cells, and a catheter connecting it all to the patient. The cells organize themselves into a mini-liver that cleans the patient's blood much like the natural organ. All eight patients were kept alive until they received donor livers.
This complex device, developed by University of Pittsburgh surgeon Dr. Jörg C. Gerlach, is just one example of how cutting-edge electronics are transforming some of medicine's far frontiers. These inventions use an exotic combination of human and synthetic tissue, silicon circuits, and tiny motors to create replacement organs that are not quite human, not quite machines. With rapid advances in component technologies, a patient might be sent home with one of these "bioartificial" tissues in the next decade or so.
Right now, most bioartificial organs are meant as temporary solutions until the patient receives a human organ. Ultimately, scientists want to "grow" living tissue that will eliminate the need for a transplant. For that, "we want to design smart materials that can sense their environment and adapt," says Allan J. Russell, director of the University of Pittsburgh's McGowan Institute for Regenerative Medicine. Bionic devices already available are halfway to Russell's goal. The Dobelle Institute in Lisbon, Portugal, has developed a pair of glasses that combine a tiny video camera, a handheld computer, and a grid of electrodes embedded in the part of the brain that processes visual images. Also available is an artificial larynx. Implanted in the mouth, it uses chips and radio signals to translate movements of the tongue and lips into words amplified on a speaker.
But the cutting edge in replacement body parts are devices that incorporate living human cells. A bioartificial kidney, developed by Dr. H. David Humes of the University of Michigan Medical School in Ann Arbor, uses a plastic cartridge containing millions of human kidney cells to replace dialysis. Tested on 10 people with acute renal failure, Humes's kidney saved the lives of six.
Such hybrid devices are born from an unusual multidisciplinary mix, drawing on chemical engineers, computer scientists, biologists, and physicians. This has led to some unique approaches. Bioengineers Vladimir Mironov of the Medical University of South Carolina and Thomas Boland of Clemson University have "printed," layer by layer, a three-dimensional sheet of living tissue using standard inkjet printers. The ink is replaced with a cell solution, and the paper with a biodegradable gel. Such blends of high and low technology could end up transforming how we define life.
By Catherine Arnst