WFIRM engineers invented a bioprinter that prints skin directly on a wound

Close-up of a nozzle for a skin bioprinter developed at the Wake Forest Institute of Regenerative Medicine

Although the appearance of three-dimensional printing is usually considered a revolution in industry, it has revolutionized medicine as well. To help heal large wounds that usually require skin grafts, engineers at the Wake Forest Institute for Regenerative Medicine (WFIRM) have developed a new bioprinter that can print two layers of the patient’s own skin directly onto the wound.

Three-dimensional skin printing has been in development for several years. In 2014, a prototype of a machine was introduced that could print large pieces of human skin, which could then be cut and glued to a wound. Over the years, technology has evolved into more technologically advanced machines and, ultimately, a portable device that acts as a tape dispenser.

The new car looks like something in between. It is much more than a portable device, but still portable in a hospital setting. The machine can be put to bed, and the patient will lie under the nozzles of the printer while he will work.

As in previous devices, the new printer uses "ink" consisting of the patient’s own cells to minimize the risk of an immune reaction. First, a small biopsy of healthy skin is done, and two types of skin cells are extracted from it: fibroblasts , cells that help build the skin structure, and keratinocytes , which are the main cells in the outermost layer of the skin.

Large quantities of these cells are grown from a biopsy sample, then mixed with a hydrogel to obtain bio printer ink. And this is how it differs from previous bioprinters - instead of just applying new skin to the wound, the machine first uses a three-dimensional laser scanner to build an image of the wound topology. Using this image, the device then fills the deepest parts with fibroblasts, and then applies keratinocytes on top.

This technique mimics the natural structure of the skin, allowing the injury to heal faster. The group showed how it works on mice and pigs, watching how new skin began to form outward from the center of the wound.

“If you use the patient’s own cells, they actively contribute to wound healing, making the healing process much faster,” says James Yu, co-author of the article. “While there are other types of wound healing technologies, they usually do not directly participate in skin regeneration.”

Engineers have planned clinical trials in humans. In the end, the new device can be used in the treatment of burns, patients with diabetic ulcers and other large wounds.

Scientific Reports
Wake Forest School of Medicine