Now, however, scientists have devised a method of growing it in 3D forms, which could be slipped onto the body like a piece of clothing.
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.