Bioprinters — 3D printers that work with biological material like cells — are gaining popularity in the field of medicine, where they can be used to print organs.
In early 2019, scientists engineered a bioprinter with a distinctive feature — mobility. The first of its kind, the proof-of-concept device could help to accelerate the delivery of care and decrease costs for patients.
"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, Ph.D., assistant professor at Wake Forest Institute for Regenerative Medicine (WFIRM), who was lead author of the paper.
The device could be filled with the patient's own cells — specifically, dermal fibroblasts and epidermal keratinocytes — which are then mixed with a hydrogel. The machine proceeds to print bi-layered skin onto a wound. In essence, the device mimics skin's natural healing but much faster.
Replacing skin grafts
If successful, the device could be game-changing for the healing of wounds. Currently, skin grafts are the most popular technique for treating large wounds, however, they come with many complications.
In addition to a lack of availability of skin to harvest, there is always the risk donor grafts will be rejected by the patient. Skin grafts may also require multiple surgical procedures and often result in scarring.
"The technology has the potential to eliminate the need for painful skin grafts that cause further disfigurement for patients suffering from large wounds or burns," said WFIRM Director Anthony Atala, M.D., and a co-author of the paper.
The WFIRM bioprinter would use a patient's own cells, ensuring they are accepted by the patient's body. Trials thus far have even shown the bioprinting system would even promote further healing.
"If you deliver the patient's own cells, they do actively contribute to wound healing by organizing upfront to start the healing process much faster," said James Yoo, M.D., Ph. D, who led the research team and co-authored the paper. "While there are other types of wound healing products available to treat wounds and help them close, those products don't actually contribute directly to the creation of skin."
In late 2019, the scientists from WFIRM continued to show off their bioprinting capabilities by printing multi-material tracheal tissue. This printed tissue was the first of its kind and is made up of both smooth muscle and cartilage cells, demonstrating similarities to human tracheal tissue. The combination of materials helps the tissue flex like a human airway.
The tissue was printed using a biodegradable polyester material and hydrogels containing human mesenchymal stem cells — cells capable of self-renewing that can become a variety of cell types.
“People have tried other materials, but the problem has been they were using just one material that is not strong enough to hold the airways open and does not provide the flexibility needed. Our bioprinting method provides a combination of flexibility and strength needed to mimic native tracheal tissue,” said Murphy.
The researchers are currently evaluating long-term function to ensure the tissue would hold up outside of a lab environment.
The study is published in Nature's Scientific Reports journal.