Image: Courtesy of Fco. Javier Alonso
In December 2008, just two weeks after her 27th birthday, Francis S.* had a radiator pipe burst in her Bronx apartment. She was leaning down at the time, with her right side angled closer to the radiator. The hot water gushing out of the broken pipe hit her left side, scalding her torso. She sustained second and third degree burns from her left wrist down to her left hip. The responding firefighters told her it was "the worst burn one could sustain."
Francis underwent three surgeries and hydrotherapy to treat the severe burns. Doctors performed a major skin grafting procedure that left her with three long strips of scarring on both sides of her torso; waking up from that procedure, she said, was the most pain she felt since actually being burned. And despite being given morphine, Francis said she "felt everything" during hydrotherapy, turning a treatment meant to reduce swelling and soothe pain into an excruciating process.Along with the physical trauma of her burn, Francis also has to explain away the curiosities of the small children she works with as a school counselor. In the summer, when she isn't wearing layers, people stare at her body. Doctors have left the door open for other surgeries, such as tissue expansion, but the thought of another procedure triggers traumatic memories from when the accident first occurred, Francis says.For the last two decades, if not more, scientists around the world have explored ways to improve treatment so that it is less traumatic to a burn patient's physical and emotional health. Now, researchers in Spain may be one step closer. In a recent paper, the scientists revealed a 3D bioprinter prototype that can produce functional human skin capable of being transplanted onto a burn survivor's wounds."To be able to grow skin outside of the body and utilize it would be amazing," Francis says, "not only cosmetically, but emotionally."
As part of the process, the scientists use bioinks—injectors mixed with biological components similar to cartridges and colored ink—to create the synthetic skin. A computer controls the production, carefully depositing the components onto a print bed. First, the protective epidermis is formed, then the thicker and deeper epidermis, mimicking the natural structure of human skin.The skin can be produced two ways: from a stock of cells for industrial use in pharmaceutical, chemical and cosmetic testing or on an individual basis using a patient's own skin cells to treat severe burn wounds and other injuries, according to the researchers. By using bioprinted skin, doctors can minimize—and even eliminate—the need for skin grafting surgeries, which only produce additional wounds and scarring for the patient, says Jose Luis Jorcano, one of the paper's authors and a professor at Spain's Universidad Carlos III de Madrid's Bioengineering and Aerospace Engineering department."The problem when you have a large wound is that you don't have enough skin," says Jorcano. "Having something like this, it's helpful to cover large areas."Jorcano's bioprinter prototype is not the only attempt at mimicking human skin for burn treatment, but it is the first functional printer to be introduced to the marketplace. Their 3D bioprinter prototype is an evolution from 25 years spent successfully transplanting laboratory grown skin onto burn patients in Spain, says Jorcano.
The Wake Forest School of Medicine is currently in the second phase of a government-funded project testing the viability and sustainability of printing skin cells directly on the burn wounds sustained by soldiers in combat. Similarly, in 2014, a team of researchers in Canada unveiled a version of the bioprinter that used cells from the burn patient to replicate skin.In preclinical trials at the time, the Canadian scientists hoped their innovation would bring burn treatment into the 21st century. "Ultimately, we need to evolve into the future," says lead researcher Marc Jeschke, a plastic surgeon and director of the Ross Tilley Burn Centre at Sunnybrook Health Science in Toronto. His team is back at square one after their experiment failed to pass the preclinical phase.Although the 3D bioprinter out of Spain is not yet available for public use, it's not that far away. According to Jorcano, the scientists are collaborating with a company to develop the technology for commercial use in pharmaceutical and cosmetic testing within a year. He said that the bioprinter should be ready for commercial use in burn treatment within the next two years. "The time will be not too long," Jorcano says.That, of course, depends on the results of future research and trials, and whether or not it clears regulatory hurdles in Europe. Still, the technology has far-reaching implications even as it exists now. If scientists are able to create a prototype that could replicate functional human skin, imagine the possibilities for applying 3D printing techniques to human organ tissue.
"All these possibilities that we couldn't think of, we were doing manually," Jorcano says. "What [we] have demonstrated for the time is that this is possible."The bioprinter would not only transform medical technology, it could also change how patients recover. Typically, it takes a few days to several months for the burn wound to heal, depending on the depth and severity of the injury; while superficial burns can take five to 10 days to heal, third-degree burns, also known as full thickness burns, usually require skin grafting in order to heal, according to the American Academy of Family Physicians.But the entire recovery process could last much longer. Francis spent years waiting for her skin glands to heal. Her skin was constantly itchy. She had to be careful of water temperature and sun exposure. She had to get used to the slight pressure of the clothes she wore. Both the accident and recovery impacted her lifestyle. But researchers have found that transplanting bioprinted skin onto burn wounds can speed up the healing process, says Jeschke."Once you're able to create synthetic skin from a patient's cells, the game changes completely because you can operate very quickly. You can do various things very effectively," he says. "3D printing is a tool that has tremendous potential."Francis, for her part, is able to find strength in her scars but sometimes wishes they weren't as visible, leaving her open, she says, to stares and judgements. Then there are all the times she's heard from others about how lucky she is that it wasn't her face. It took her years to stop cringing at that line."My scarring is extremely significant and is a daily reminder of what happened to me," Francis says. "I wonder what these years would have been like for me had there been this type of technology."