A mobile machine has been created that may help heal wounds by using patient's cells and printing new skin onto large wounds and burns. The skin bioprinting system, created by scientists at Wake Forest Institute for Regenerative Medicine (WFIRM), was designed to print bi-layered skin directly onto a wound.
This is very exciting because we can now print biocompatible materials, cells, and supporting components into complex 3D functional living tissues. Not only that, but the technology can also be used for regenerative medicine to address the need for tissues and organs suitable for transplantation.
“The unique aspect of this technology is the mobility of the system and the ability to provide on-site management of extensive wounds by scanning and measuring them in order to deposit the cells directly where they are needed to create skin,” said Sean Murphy, a WFIRM assistant professor.
Because millions of Americans are affected by large, chronic, or non-healing wounds, scientists knew there was a strong need for this technology. Treating these wounds is often expensive and time-consuming because they often require multiple treatments. The scientists hope that the machine will also be used to prevent combat casualties caused by burn injuries. Burn injuries are currently responsible for 10-30% of combat casualties for military personnel in conventional warfare.
Before the machine can reprint new skin, a small biopsy of uninjured tissue needs to be taken. The two major skin cells, dermal fibroblasts and epidermal keratinocytes are collected and expanded. Fibroblasts are responsible for healing the wound by synthesizing the extracellular matrix and collagen. Epidermal keratinocytes comprise 90% of all cells in the epidermis (outermost layer of the skin).
Once the cells have been extracted, they are mixed into a hydrogel and then put into the bioprinter. The machine uses integrated imaging technology to scan the wound and relay information to the software, which tells the printer which cells to delivery exactly where in the wound layer by layer. The bioprinter directly deposits the cells into the wound which replicate the layered skin structure. By doing this, the formation of normal skin structure and function is significantly sped up.
The machine is currently still in the prototype stage. The scientists were able to show proof-of-concept by printing skin onto pre-clinical models. Next, they want to test the machine on humans. “Currently, skin grafts to treat wounds and burns are the “gold standard” technique, but adequate coverage of wounds is often a challenge particularly when there is limited availability of healthy skin to harvest. Skin grafts from donors are an option, but risk immune rejection of the graft and scar formation,” said Sean Murphy, Ph.D., a WFIRM assistant professor who was the lead author of the study. “With the WFIRM bioprinter system the researchers could see new skin forming outward from the center of the wound and this only happened when the patient’s own cells were used because the tissues were accepted and not rejected.”
If this machine is approved to treat humans and is successful, it can eliminate painful skin grafts and further disfigurement for people with large wounds or burns. The machine would be able to offer faster delivery of care, as well as decreased costs for patients.
“If you deliver the patient’s own cells, they do actively contribute to wound healing by organizing up front to start the healing process much faster. While there are other types of wound healing products available to treat wounds and help them close, those products do not actually contribute directly to the creation of skin," said James Yoo, who led the research team and co-authored the paper.