Although flat sheets of bioengineered skin may work OK for grafting onto relatively smooth, featureless body parts, they don't work well for more complex areas, like the hands. In such cases, multiple sheets usually have to be stitched together to accommodate all the nooks and crannies – it's a laborious and time-consuming process.

Led by Asst. Prof. Hasan Erbil Abaci, a team at Columbia University set out to develop a more accommodating alternative.

The system they created begins with a 3D scan being performed on the body part which requires the graft. That scan is used to 3D-print a hollow, permeable, life-size model of the part.

Next, the outside of the model is seeded with skin fibroblast cells (which generate skin's connective tissue), collagen (which provides skin with its structure), and keratinocyte cells (which make up the outer layer of the skin). The inside of the model is perfused with growth media, which nourish the cells located on the outside.

Once those cells have grown into actual skin, that skin is removed from the model all in one three-dimensional piece, pulled over the actual body part for which it was made, and sutured into place. It takes about three weeks to grow skin in this manner, which is about the same amount of time it would take to grow traditional flat sheets.

In lab tests performed so far, 3D grafts made of human skin cells were successfully applied to the hind legs of mice. The surgery itself took only about 10 minutes, and the grafts were fully integrated into the surrounding mouse skin with four weeks. Additionally, the one-piece grafts were found to be mechanically stronger than if they had been made from multiple stitched-together sheets.

Needless to say, much more research needs to be conducted before human trials can take place. Nonetheless, it is hoped that patients may eventually be able to receive such grafts, grown from their own cells. It's even possible that the technology could provide a better alternative to face transplants, which currently utilize facial tissue harvested from cadavers.

"Three-dimensional skin constructs that can be transplanted as 'biological clothing' would have many advantages," said Abaci. "They would dramatically minimize the need for suturing, reduce the length of surgeries, and improve aesthetic outcomes."

The research is described in a paper that was recently published in the journal Science Advances.

Source: Columbia University Irving Medical Center via EurekAlert