Updating the 'Ancient' Science of Burn Care- Reported by Bronca, Tristan. Medical Post; Toronto, ON
April 26, 2016
The medical Post summarizes how Dr. Jeschlce's team will one day print a skin replacement that "completely" mimics ordinary skin, U of T professor (and developer of the printing technology) Dr. Axel Guenther (PhD) held more modest expectations. "If you've seen some of the current clinical outcomes for burn surgery, completely,' gets a different definition," he said. "While lots of steps still need to be taken, I think the new technology is transformative."
How one physician is using 3D printing technology to propel the field into the future
If you ask Dr. Marc Jeschke, engineering a true-to-life skin replacement for burn victims is a bit like figuring out how to get a human to Mars.
At present, he and his team at Sunnybrook Health Sciences Centre and the University" of Toronto are using 3D printing technology to create a unique skin substitute that's placed directly on a wound and heals as if it were the patient's own tissue. At least, that's the goal. It's never been tested on human patients before and, like getting to Mars, there are still so many unknowns it's impossible to predict if that goal will ever be accomplished.
"The vision is nice," said Dr. Jeschke. "To print out (skin cells) in a 3D matrix is actually an ideal scenario because you can define where you want the cells to be to mimic your skin." But with that come a few critical assumptions: that you have a matrix that allows several different cell types to grow'; that you know which cell types form different features on the skin, such as sweat glands and hair follicles; that you have a source for these cells that doesn't involve jabbing needles into unfathomably sick patients; and that you can be sure these cells will survive and grow in the delicate, printed assemblage.
"Will we be the Holy Grail for the future of burn care? I don't think so," said Dr. Jeschke. But he wholeheartedly believes that within 20 years, someone will have developed an off-the-shelf skin substitute that mimics a patient's skin better than what's cut from a cadaver or the patient's own body. And he believes that his team will be a big part of that development.
An unexpected interest
Dr. Jeschke wasn't initially interested in treating burns. He actually wanted to become an upper GI surgeon. But in 1994, when he completed his MD at Eberhard Karls University in Tübingen, Germany (near Stuttgart), the chair of his program chose him for a research stint at the University of Texas Medical Branch in Galveston. That program is affiliated with the Shriners Hospitals for Children network, known for its world-class pediatric burn care program.
Dr. Jeschke would return to Germany to complete his PhD, but went back to Texas in 2004 at the request of his mentor, Dr. David Herndon, a celebrated burn surgeon and director of research at Shriners. "Being exposed to these burned patients, I was fascinated with trying to keep them alive," said Dr. Jeschke, explaining that those with severe burns come dangerously close to death on a daily basis. "The other aspects of surgery just weren't as appealing anymore."
When he took over the directorship of the Ross Tilley Burn Centre at Sunnybrook in 2010, the department had been depleted to a core of just two physicians and the research program was non-existent. Dr. Jeschke reinvigorated the unit, now the largest in Canada, and with funding from major agencies like the National Institutes of Health and several donors, he founded the research program in conjunction with the University of Toronto. He also brought in standard protocols for ICU care to ensure burn patients received the same care regardless of who was on duty and, soon, Ross Tilley earned a prestigious designation from the American Burn Association-one of only four centres outside the U.S. to do so.
The printed skin initiative maybe his most ambitious lab-based project, but Dr. Jeschke has broken new ground in other areas as well. Studies are underway to determine why elderly patients react more severely to burns than younger adults-a so-far unexplained phenomenon. Other research will explore the longer-term psychological and physiological impacts of serious burns.
An overdue revolution
The current standard for burn care still involves donor skin, something that dates back to the 5th century. For smaller burns, the skin is often taken from an uninjured area on the burned patient, effectively doubling the size of the wound.
Patients with more extensive burns may receive artificial grafts (like Integra, a delicate substitute made of bovine collagen and silicone which has been the gold standard for about 20 years) or experimental cultured skin grafts, neither of which have replicated finer skin features like colour, sweat glands and hair follicles. Cultured skin grafts also cost hundreds of thousands of dollars and take weeks to grow in vitro. By the time these can be grafted, the patient is often either healed or dead, Dr. Jeschke said.
The 3D printed method is different in that stem cells would grow in vivo. Dr. Jeschke was affiliated with a recent study in Cambodia that showed even basic labs can store the cells for extended periods of time and the methods for grafting them to a patient are no different than your standard-of-care graft. This means if the concept is proven, all that w'ould be required is access to the technology Dr. Jeschke and his team are currently refining-like a kit to "print your own skin, so to speak"-and relatively basic training to scale out to areas around the world, where extensive burns are more often fatal than in Canada or the U.S.
The printed product has shown tremendous promise in rodent trials and Dr. Jeschke hopes human trials wall begin in the next three to five years.
As for the likelihood that Dr. Jeschlce's team will one day print a skin replacement that "completely" mimics ordinary skin, U of T professor (and developer of the printing technology) Dr. Axel Guenther (PhD) held more modest expectations. "If you've seen some of the current clinical outcomes for burn surgery, completely,' gets a different definition," he said. "While lots of steps still need to be taken, I think the new technology is transformative." MP