A patient with severe burn injuries is brought to a burn center, in need of a skin graft immediately. A surgeon comes in with a small, handheld device and quickly dispenses thin sheets of artificial skin onto the wounds as easily as rolling out Scotch tape.
This scenario could become reality, thanks to a new device developed by Canadian scientists: a handheld 3D skin printer that deposits layers of skin tissue on burns and other injuries.
“I’m pretty convinced it’s a very capable approach that we’re pursuing,” says Axel Guenther, a professor of engineering at the University of Toronto, who supervised the research. “It does have a chance to actually make it in to the clinics.”
Currently, burn patients face an extremely rough road. Burn injuries are notoriously painful, difficult to heal and prone to infection. Typically patients with serious burns will receive an autologous skin graft, where doctors shave off a piece of healthy skin to cover the injured area. But if the burn is very large, there’s not enough healthy skin to go around. Plus, shaving off healthy skin creates a new injured area, another source of pain and possible infection.
Because of these challenges, researchers have long been looking for methods of creating artificial skin grafts, either from biological or synthetic materials. There are a number of such products on the market, but they have limitations: some are expensive, some can only be used temporarily, some take weeks to create from the patient’s own skin cells.
The University of Toronto researchers developed a printer the size of a shoe box, weighing less than one kilogram (2.2 pounds). It dispenses strips of “bio ink” made of biological materials. These materials include collagen—the most abundant protein in the dermis, or middle layer of the skin—and fibrin, a protein needed for wound healing. The strips of artificial skin can be deposited directly on the injured area.
“The analogy is a duct tape dispenser, where instead of a roll of tape you have a microdevice that squishes out a piece of tissue tape,” says Guenther. It's also been compared to a white-out dispenser.
The research was published recently in the journal Lab on a Chip.
The researchers have successfully tested the device on pigs, and hope to move to human trials in the next few years. If the device works on humans, the team will need to work closely with burn surgeons to study operating room workflows, to develop a system that meets their needs in terms of size and speed.
One of the biggest challenges in developing synthetic skin graft products and techniques is infection, says Palmer Bessey, the associate director of the William Randolph Hearst Burn Center at New York-Presbyterian/Weill Cornell Medical Center.
"People with big burns are susceptible to getting infections," Bessey says. "And the infection will interfere with the healing of the wound. It can cause all of this fancy expensive magic material to not survive at all."
For a new material or technique to work, it would need to be able to withstand infections. An ideal material and technique would also leave less of a scar than traditional grafts.
"The material, you’d want it to survive the rough environment of an actual sick patient," Bessey says.
Bessey says the Toronto research shows promise in that it could potentially produce large amounts of skin graft material in a short time.
"The longer patients lie around with open wounds, the more susceptible they are to infections," he says.
There are many research teams in America and abroad currently working on making better skin grafts, Bessey says.
"It would be a fabulous thing, just fabulous," he says. "But there are real challenges."