Rootstown, Ohio — Adult stem cells may have a greater role in wound healing in the future, according to William J. Landis, Ph.D., Northeastern Ohio Universities Colleges of Medicine and Pharmacy, Rootstown, Ohio. He says that research utilizing such cells for wound healing is currently at various stages of preclinical and clinical studies, and that investigators will not know for some time if this approach has long-lasting, therapeutic benefits.
"Stem cell therapy has shown tremendous progress and promise in treating a variety of pathologies," Dr. Landis tells Dermatology Times.
"Dermatologists should know that investigators are exploring the possibility of promoting wound healing with stem cell therapy," he says.
"Stem cells may be readily available, depending on techniques used to isolate and transform them into different cell types," he says.
"For example, we can now obtain quantities of adult stem cells from cord blood or bone marrow, and then, with appropriate methods, we can modify them into the types of cells that would be needed for specific applications, like healing burns, diabetic ulcers and deep wounds in muscles," Dr. Landis says. He says that adult stem cells have shown some promise in treating diseases such as multiple sclerosis, type I diabetes and scleroderma. Therefore, using them more widely in wound healing is a logical step. "These are difficult pathologies to treat by other means," Dr. Landis says.
"So the application of adult stem cells to these relatively intractable pathologies gives us the hope that they may really work wonders when applied further to wound healing," he says.
Cells cultured with matrix
Dr. Landis says that he and his co-workers have been conducting tissue-engineering research with bovine models to assess the feasibility of stem cells to heal wounds in bones, cartilage and tendons.
"We may apply the adult stem cells directly to a wound in some instances. We do this by growing the cells under culture conditions to develop an extracellular matrix, which creates a supportive environment for the cells. We collect both cell and extracellular material and apply the combination to a system in which a defect has been artificially created in a bone. We then monitor changes in the defect over time following cell/matrix treatment.
"In monitoring, we analyze the expression of certain genes and the secretion of certain proteins, comparing them to normal bone tissue and to bones that have no cell/matrix application," Dr. Landis says. "We examine our system over time to see if there’s any new tissue growth to heal the defect," he says. "We include multiple sets of experiments that have the same or different tissue defects, and we want to compare the studies to determine whether normal tissue develops to overcome the created wounds. "At present, some of our results show cellular materials that we expect are being produced in our systems. That’s the kind of success we have at the moment," Dr. Landis says.
Although major research still focuses on animal models, Dr. Landis and colleagues are beginning to examine the use of human adult stem cells from cadavers. As with the bovine models, the laboratory staff members isolate the cells and attempt to grow the mix of cells and matrix that would eventually be applied to a human wound.
"“There are many steps required in this approach in order to achieve ultimate clinical application," Dr. Landis says.
Embryonic stem cells
Dr. Landis says that investigators are also interested in the possibility of using human embryonic stem cells either in addition to or instead of adult stem cells.
"Embryonic stem cells have a great deal of plasticity and can be induced to develop into a wide variety of cells," Dr. Landis says. "Adult stem cells are not necessarily as versatile. They’ve already reached a maturation stage where you can’t tweak them into the same types of cells that you can with the embryonic stem cells. "On the other hand, very recent reports indicate that embryonic stem cells may be derived from adult stem cells, and the interchange then may lead to a much larger availability of the embryonic cells," he says.
Although current clinical use of stem cell therapy for wound healing is limited, Dr. Landis sees the potential for its coming to fruition.
"Stem cell therapy is a tremendous paradigm for wound healing," he says.
"Serious cutaneous and connective tissue pathologies should be treatable with stem cells. This is an area of medicine that has broad potential, and I would encourage dermatologists to be involved in the research investigating stem cell use for wound healing in as wide a spectrum of applications as possible," Dr. Landis says.