3D Printable “Skin in a Syringe” for Healing Burns

Skin is the body’s first line of defense against the outside world, and when it suffers severe burns, repairing it can be a matter of life and death. Current treatments often involve transplanting a thin layer of the epidermis, the outermost skin layer, made up of a single cell type. While lifesaving, this approach frequently results in significant scarring. Now, researchers from the Center for Disaster Medicine and Traumatology and Linköping University have developed a gel containing living cells that they hope to 3D print into skin transplants for burn victims.

Beneath the epidermis lies the dermis, a thicker, more complex layer that houses blood vessels, nerves, hair follicles, and other structures essential for skin’s function and elasticity. Transplanting the dermis itself is rarely feasible, as doing so would create a new wound as large as the original injury. To overcome this challenge, the team sought a new solution: engineering living skin that could replace and regenerate the dermis.

A graphical abstraction of the study. (Image credits: R. Shamasha et al.)

Creating the Bioink

The dermis is made up largely of fibroblasts—connective tissue cells that are both easy to harvest from the body and simple to grow in the lab. These cells are especially valuable because they can mature into more specialized cell types as needed. To cultivate them, the researchers used a scaffold made of tiny, porous gelatin beads. However, this method produced a liquid that would not stay in place on a wound. To solve the problem, they blended the gelatin beads with a hyaluronic acid–based gel, creating a material with a remarkable property: it turns into a liquid when subjected to light pressure.