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

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

Although the appearance of three-dimensional printing is usually considered a revolution in industry, it also revolutionized medicine. To help cure large wounds that usually require a skin graft, 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.

3D skin printing has been in development for several years. In 2014, a prototype machine was introduced that could print large pieces of human skin, which could then be cut and glued to the patient on the wound. Over the years, technology has evolved into more technological machines and, ultimately, a portable device that works as an adhesive tape dispenser.

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

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

Large quantities of these cells are grown from a biopsy sample, then mixed with a hydrogel to obtain a bioprinter ink. And this is how it differs from previous bioprinters - instead of simply applying a new skin on a wound, the machine first uses a three-dimensional laser scanner to build an image of the topology of the wound. 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 as new skin began to form outward from the center of the wound.

“If you use the patient’s own cells, they actively promote 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 are usually not directly involved in skin regeneration."

Engineers have planned human clinical trials. In the end, the new device can be applied in the treatment of burns, patients with diabetic ulcers and other large wounds.
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Scientific Reports
Wake Forest School of Medicine