Bioengineers have grown a “glove” of skin for transplantation

Bioengineers have grown a “glove” of skin for transplantation

Columbia University has come up with a type of skin that takes only 10 minutes to transplant. According to doctors, this will be a breakthrough in the treatment of burns and large wounds.

In the lab of Alberto Pappalardo, a physician who specializes in dermatology and tissue engineering at Columbia University Medical Center, they have grown a specialized material – a “skin construct” – a whole sheet of human cells that can be implanted in a wound too large for a graft from another part of the body.

The technology of growing skin structures has not changed much in 40 years – as a rule, they are flat rectangular or round patches. This is a problem, says Hassan Erbil Abachi, an assistant professor, bioengineer and adviser to Pappalardo, because these shapes do not match the shapes of body parts such as fingers and faces. The imposition of two-dimensional patches on three-dimensional contours requires more of them, which means more lengthy and traumatic operations.

In an article in the journal Science Advances, the team described the technology for making a three-dimensional graft that is shaped to fit a particular body part and does not have sutures. The scientists started by 3D printing a scaffold that allows skin cells to grow into the desired shape. Pappalardo seeded human cells in layers around the scaffold and then waited for those cells to build a dense network of structural molecules. The engineered skin turned out to more closely mimic form and function than any before it, and when tested on a mouse, it integrated as if it were native skin. The overlay procedure took 30 seconds, and the entire operation took 10 minutes.

Abacha’s team began their experiment by growing skins with a simple cylindrical shape. The researchers used 3D scanning or a digital model to print a permeable plastic scaffold for cells in two layers of the skin – the inner dermis and the outer epidermis. Pappalardo molded fibroblasts (dermal cells) with collagen around the building frame. Within two weeks, the layer matured, and then the scientist sowed keratinocytes – epidermal cells. This combination was exposed to air on one side and liquid on the other for a week – like our skin. And it worked. “We thought, if we can make a cylinder, then we can make any shape,” Abachi says.

The breakthrough sparked a debate: one group of scientists wanted to grow a face, another a hand. The second one won. They envisioned a five-fingered structure that could be opened at the wrist, worn like a glove, and then stitched. “You will only need stitches in the wrist area, and that will be the end of the operation,” Abachi says.

The lab printed a five-fingered scaffold the size of a sugar pack, prepared the cells as before, and then tested how well the structure held up compared to traditional grafts. When tested for mechanical deformation, “limitless” structures outperformed flat structures by 400%.

Experiments on mice, conducted 11 times, showed that such a skin graft can actually take root. Four weeks after skin replacement, the artificial construct was fully integrated.