Growing artificial skin from patients' own cells

There is new hope for patients with chronic wounds: euroderm GmbH and the Fraunhofer Institute for Cell Therapy and Immunology IZI in Leipzig have been granted approval to produce artificial skin from patients' own cells.

It sounds like something from a science fiction novel: Pluck a few of someone’s hairs, and four to six weeks later they have grown into a piece of skin. Of course, what researchers at the Fraunhofer Institute for Cell Therapy and Immunology IZI in Leipzig have recently started doing in their new cleanrooms isn’t quite as simple as that. “We and euroderm GmbH have been given permission to grow dermal tissue for grafting onto chronic wounds such as open leg ulcers on diabetics patients,” says IZI team leader Dr. Gerno Schmiedeknecht.

At present, chronic wounds are treated by grafting on the patients’ own skin, which is normally taken from the thigh. This leaves scars on both the thigh and the treated wound. “If we produce this skin using the recently approved EpiDex® technique instead, we can achieve the same chances of recovery without hurting the patient. Moreover, the artificial skin grows onto the wound without scarring,” says Dr. Andreas Emmendörffer, managing director of euroderm GmbH. Another advantage is that the transplantation can be performed on an outpatient basis. A few days later, it is already possible to see whether the new skin has adhered to the wound. 72 days later, the grafted skin can no longer be distinguished from healthy skin.

But how exactly is the new skin grown? “We pluck a few hairs off the back of the patient’s head and extract adult stem cells from their roots, which we then proliferate in a cell culture for about two weeks. Then we reduce the nutrient solution until it no longer covers the upper sides of the cells, exposing them to the surrounding air. The increased pressure exerted by the oxygen on the surfaces of the cells causes them to differentiate into skin cells,” explains Emmendörffer. In this way, the researchers can grow numerous small pieces of skin, produced individually for each patient, which add up to a surface area of 10 to 100 square centimeters when pieced together. To ensure that they comply with the safety regulations at all times, the researchers are using new cleanrooms at the IZI, a state-of-the-art facility for producing different kinds of cell therapeutics. “We continuously measure the number of particles in the cleanrooms. If there are too many particles in the air, an alarm goes off,” says Schmiedeknecht. The researchers expect to grow skin grafts for 10 to 20 patients a month in 2008, depending on how many doctors prescribe this therapy.