We’ve all seen those Looney Tunes cartoons where the helmeted Marvin the Martian toasts his enemies with a single zap from his little ray gun. Consider Dr. Jörg Gerlach of the McGowan Institute for Regenerative Medicine the cartoon character’s perfect antithesis.
Gerlach wields his own futuristic, highly powerful gun. But unlike the Martian’s, Gerlach’s gun makes burns disappear. He came to Nebraska Wesleyan University from Pittsburgh in January to discuss the gun’s role in an innovative new treatment for victims of severe burns.
Gerlach’s gun joins an arc of medical developments that have made burns steadily less lethal over the last eight decades. Gerlach shared data with his NWU audience outlining improvements in burn care. In 1940, a person with burns to 30 percent of the body faced 50/50 odds of survival. In 2000, a person with burns to more than 80 percent of the body typically faced the same odds.
Developments in antibiotics and grafting techniques drove early gains in burn survival. These advancements were followed by the arrival of highly specialized burn centers and improved dermal replacement techniques.
But Gerlach said even modern skin grafting has its drawbacks. For one, it’s time intensive.
“The standard techniques we have now take weeks—months, sometimes,” said Dr. Stephen Wolf, director for clinical research at the U.S. Department of Defense Burn Center and Institute for Surgical Research in San Antonio, Texas. Speaking with National Geographic, he continued, “And the reason people die is because of infections that develop while we’re waiting for the skin to heal.”
Grafts also behave like a blanket over a wound. As the wound weeps underneath its graft, the fluid can interfere with healing and the graft’s ability to take.
And grafting isn’t right for every burn. Second-degree burns, Gerlach explained, come in two levels. In a 2a burn, the thin layer of tissue between the dermis and epidermis remains at least partially intact. This layer contains skin stem cells or basal keratinocytes, which drive new skin cell production. In a 2b burn, this layer is destroyed. While these burns look virtually identical, they are quite different in one respect. A 2a burn will heal spontaneously. A 2b burn will not.
“Two-b or not 2b?” is the central question for physicians placing skin grafts. Unnecessarily grafting a 2a burn means additional scarring and perhaps decreased functionality for the patient. But failing to graft a 2b burn prolongs the risk of life-threatening infection. And such an infection must be defeated before a second graft attempt could take place.
Gerlach’s spray gun addresses all of these weaknesses. The process works like this. When a patient arrives with severe burns, doctors take a portion of healthy skin from the patient and extract precious cells from that layer containing basal keratinocytes. These stem cells are then mixed in a solution and loaded into Gerlach’s gun. A doctor promptly sprays the wounds with this mixture. The entire treatment—from biopsy and cell preparation to spray application—is complete within 90 minutes of the patient’s arrival.
Dr. Wolf called this means of getting “normal, healthy skin—as much of it as we want—within a week… the Holy Grail in burn surgery.”
There is no waiting for a graft to grow or take. The evenly sprayed stem cells immediately create tiny islands of healthy and dividing skin cells that grow and connect with one another until the wound is covered. Spraying over 2a burns doesn’t appear to inhibit natural healing. And, because the wound is sprayed with the solution rather than blanketed by a graft, it may weep naturally without interfering with the islands of working basal keratinocytes.
The results are breathtaking. While grafted patients wait weeks or months to heal, patients sprayed by Gerlach’s skin cell gun are sometimes completely healed in four days. Dr. Wolf called this means of getting “normal, healthy skin—as much of it as we want—within a week… the Holy Grail in burn surgery.”
Gerlach was quick to point out to his NWU audience that he didn’t invent this skin gun. But he did reengineer it to increase its effectiveness. He described early iterations involving little more than a syringe with a sprayer tip. Achieving proper pressure for dispersing the solution proved wildly difficult. “Pressing too hard with your thumb on the plunger only killed the cells,” Gerlach said. “Press too soft, and the solution dripped rather than sprayed,” leaving parts of the wound untreated. The sweet spot was too small to reliably hit with the human thumb—especially in an emergency situation above a deeply suffering patient.
Gerlach’s design digitizes the pressure, giving doctors computerized control over the spray.
Gerlach also experimented with culturing the stem cells. If he could get results from the modest portions of basal keratinocytes he could receive via biopsy, perhaps he could improve those results by taking the time to culture more cells through an in vitro method.
That approach didn’t pan out. While it did increase the concentration of cells in his solution, many of those stem cells simply matured in the culture dish and lost their basal kerotinocytes. In this case, “less immediately” is better than “more later.” “Even with fewer cells in the spray, outcomes improved with early application,” Gerlach said.
The opportunity to see and hear from the physician, researcher and engineer behind one of medicine’s “Holy Grails” was a powerful motivator for NWU students in the sciences.
“Dr. Gerlach’s lecture and interaction with students was a great opportunity for our students,” said Associate Professor of Biology Angela McKinney. “It was wonderful for students to see how different fields of science, like biology and physics, work together to help advance the medical field. Experiences like this inspire students to explore scientific research because they can see for themselves the tremendous potential there is to save and improve people’s lives.”
Gerlach’s experimentation has yielded a powerful new weapon against burns. “It looked like something you’d see in Star Wars,” said Matthew Uram, a state police officer from Pennsylvania, and one of the first burn patients to come under the crosshairs of Gerlach’s gun. After an accident at a bonfire, Uram arrived with second-degree burns to his face, neck, shoulder and arm.
While the gun may resemble something from a sci-fi movie, Uram decidedly does not. Sci-fi makeup artists love nothing more than disfigurement and scars. But thanks to a direct hit from Gerlach’s skin cell gun, Uram’s face and arm look better suited today for a romantic comedy. He looks perfectly normal.
“They did [the spray treatment] on a Friday and my follow-up was Monday,” Uram said. “And the burn unit said it was healed—completely.”
See Gerlach’s skin cell gun and Uram’s remarkable recovery at nationalgeographic.com. (Be advised: the video contains graphic footage of burn wounds.)
Watch Gerlach’s NWU lecture at "Watch Live Events” then select “Dr. Jörg Gerlach, ‘Stem Cell Spray Gun’”.