The new device, developed by scientists at the University of Toronto, is not the first to 3D-print skin, but the team thinks it is the most portable and efficient one to date.
A new glue gun-like device can 3D-print three layers of skin on demand to treat even the most severe flesh wounds in under two minutes. Burns and deep flesh wounds are usually treated skin grafts, but the procedure comes with many drawbacks, like tissue shortages and rejections.
In their new paper, the scientists demonstrate that their ‘gun’ can repair deep tissue wounds safely and effectively in animals, showing promise that it may one day change the way we treat such injuries in humans.
Researchers from Toronto University proved that their new glue gun-like skin 3D-printer can safely replace all three layers of skin for animals with deep wounds.
Though its complexity is often taken for granted, the skin is the body’s largest organ.
The skin is remarkable for its ability to heal itself, but large, deep wounds require too much work for the body to do alone – and our medical technology often falls short, too.
Typically, flesh wounds are treated with skin grafts, taken either from other parts of the body or from donors. But each of these solutions come with steep hurdles when it comes to treating large or deep wounds.
People can only spare so much of their own healthy skin from other locations, and, even if doctors can acquire enough donor skin to treat large wounds, the patient’s body might reject the foreign skin.
Such large specimens of donor skin are even harder to find when they need to treat deep skin wounds that affect all three layers – the epidermis, dermis and hypodermis.
Acquisition of this skin can take a long time, which presents a life-threatening danger to people with deep skin wounds who are especially helpless against infections or dehydration that could kill off more skin.
Because it doesn’t beat like the heart or inflate like the lungs, we tend to forget that the skin is very much a living organ but its layers are teeming with complex types of cells and substructures, all of which protect us from the outside world.
The thin top epidermis contains immune cells called keratinocytes to fight infections and help us to retain moisture and melanin to protect against UV radiation.
The three layers of ‘bio-ink’ the device lays down even resemble hot glue when they are used to fill deep flesh wounds. Below it, the dermis produces collagen, which gives our body’s shield both its elasticity and firmness.
Hairs that help to regulate our body temperature also have their roots in the dermis and it is home to sweat and glands, blood vessels and nerves. Beneath these is the hypodermis, a fatty layer that provides cushion to our muscles and bones and keeps the skin attached to them.
Scientists can now grow or print skin in the lab, but making such a complicated organ from scratch takes time that the patients who need it most may not have.
‘Most current 3D bioprinters are bulky, work at low speeds, are expensive and are incompatible with clinical application,’ said study co-author Axel Guenther.
The longer patients wait for skin, the more likely they are to get an infection, and the harder it will be for whatever graft is eventually placed to heal.
The new printer dispenses strips of ‘bio ink’ equipped with elements to grow new skin.
Stem cells taken from a patient are plugged into the device and used to generate three sheets composed of crucial protein bases for components of the skin, including fibrin – which helps to heal wounds and collagen.
Just like a glue gun, the dispenser is simply rolled along the wound, where it lays down a gel composed of the three bio-inks, filling deep wounds. The device is barely bigger than an envelope, only a few inches thick, and weighs just over two pounds.
Its operation is little more complicated than a regular glue gun, and at such a portable size, it’s easy to imagine it being used by EMTs in the field some day.
The study authors showed off the gun’s incredible ability to heal by using it to fill deep cross-sections. Most importantly, ‘our skin printer promises to tailor tissues to specific patients and wound characteristics,’ says lead study author Navid Hakimi.