Burn Research without Animals
Severe burns pose a difficult medical challenge. Treatments are limited for patients with extensive third-degree burns, and, even in the best of circumstances, long hospital stays are the rule.
Research scientists Charles W. Hewitt, Ph.D., Edward Doolin, M.D., and colleagues at the Robert Wood Johnson Medical School/Cooper Health System in Camden, New Jersey, are hoping to change that. Working with both cloned cells and bioengineered tissues, Drs. Hewitt and Doolin have created living human skin to serve as an experimental model for burn research. Employing space-age technology, Dr. Hewitt’s laboratory grows skin in a micro-gravity environment and uses it to study burns, immune rejection, and other related issues. This human-based model not only replaces the use of animals, but can be far superior.
As Dr. Hewitt explains, “One advantage is that you can engineer these tissues any way you want, so they actually come out human. A real advantage over animals is that you can use human reagents—those chemicals, probes, and therapies that are used on an actual burn patient—and get immediately relevant results.”
As Director of Surgical Research, Dr. Hewitt is investigating mechanisms of how skin is injured, sometimes in combination with infection or reduced immunity, and how transplanted skin rejects.
Having lost a major portion of their skin, burn patients are vulnerable to bacteria, viruses, and fungi. To restore their lost protection, doctors must remove a portion of what little healthy skin the patient has left and expand it—stretching the skin to cover up to ten times its original area. Then, that skin must be grafted onto the patient, allowed to grow, and then removed again to be stretched and re-grafted, and so forth. The process is traumatic and, in the meantime, the remainder of their body not covered with their own skin must be protected. A few options—from donated human skin from cadavers to commercial skin cultures—exist, but their effectiveness may be limited. The patient’s body can recognize them as foreign and ultimately reject the skin, just as a kidney or heart recipient might reject a transplanted organ.
Using bioengineered human skin, Dr. Hewitt is able to study this rejection process in an actual human model. His research is aimed at developing better methods to counter immune rejection and, ultimately, new models for studying diseases.
Theoretically, if skin can be bioengineered, so can organs such as livers and kidneys, reducing complications related to organ rejection. Ideally, a kidney, for example, could be bioengineered from tissue taken from the patient’s own failing kidney, thus creating a replacement organ that is genetically identical to the one being replaced.
Dr. Doolin, as Director of Pediatric Surgical Research, sees applications to help correct birth defects. “In some situations, reconstruction of organs damaged by a birth defect is stalemated by inadequate tissue quantities or inadequate organs,” he explains. “One of the things that we view as a future application of this work is to be able to use a sample of a patient’s tissue to construct a new organ that can be transplanted.”
Dr. Hewitt emphasizes that his research is just a first step toward achieving such success. However, it is a step being pursued in a way that clearly relates to human health, without relying on animal experiments—an example of research done right.