Swiss researchers have achieved a major breakthrough in the development of bioengineered skin. The new grafts, which are about to undergo clinical trials, work a lot like the real thing — because they actually contain functioning blood vessels and lymph capillaries.
The breakthrough was made by Daniela Marino and her team from the Tissue Biology Research Unit at University Children's Hospital Zurich. It's another amazing advance in the field of tissue engineering — one that's poised to help patients with severe burns who don't have enough of their own healthy skin available for grafts. The same technology could also be applied to cosmetic surgery.
Like the Real Thing
What's remarkable about these new skin grafts — which have only been tested on rats — is how much they work like human skin. They're equipped with not just blood vessels — which transport nutrients, oxygen, and other essential factors that keep organs alive and functioning — but lymphatic capillaries as well. These are necessary to prevent the build-up of fluids that can kill the graft before it has time to become part of the patient's own skin. Lymph vessels remove fluid from the tissue and return it to the bloodstream.
The researchers say their findings strongly suggest that if an engineered skin graft containing both blood and lymph vessels would be transplanted on humans, fluid formation would be thwarted, wound healing improved — and it would result in an enhanced ability to grow skin that looks, feels, and functions like the real thing.
To this point, bioengineered skin grafts have not contained the components of real skin, including blood and lymphatic vessels. Looking ahead, researchers will also have to figure out a way to add pigmentation, sweat glands, nerves, and hair follicles. Other unrelated research projects are striving to give artificial skin the capacity for sensitivetouch.
To create the skin grafts, the researchers used human cells from blood and lymph vessels. They were placed in a solution that scattered the cells onto a skin-like gel. After spending some time in an incubator, the mixture grew into skin grafts.
These grafts were then tested successfully on rats. The transplanted skin morphed into near-normal skin. Then, after connecting the grafts to the rats' own lymph system, it collected and drew fluid away from the tissue.
But not everyone's enthused about the prospect. HealthDay science reporter Steven Reinberg explains:
Dr. Alfred Culliford, director of plastic, reconstructive and hand surgery at Staten Island University Hospital in New York City, called the bioengineered tissue "a technology in search of a purpose."
"I don't think it will be broadly applicable to many people who need skin grafts," Culliford said. "It may be helpful in burn patients who have had a large portion of their body surface burned and don't have enough healthy skin to transplant."
Culliford said the best grafts for most patients still come from the patient's own skin. In addition, he said he doesn't believe adding lymph vessels to a graft is a great advance, since fluid drainage is now done by methods such as compressing the graft.
Unswayed, Marino says the new tissue is a true advance. Human trials are next.
Read the entire study at Science Translational Medicine: "Bioengineering Dermo-Epidermal Skin Grafts with Blood and Lymphatic Capillaries." Additional source: HealthDay.
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