A team of researchers from the Rensselaer Polytechnic Institute in Troy, NY has achieved a breakthrough in the ability to 3D bioprint living, vascularized skin tissue. The team presented the new technique for producing skin tissue with integrated blood vessels in the journal Tissue Engineering Part A.
The research project was led by Pankaj Karande, an associate professor of chemical and biological engineering and a member of the Center for Biotechnology and Interdisciplinary Studies (CBIS). Karande has been working in the field of printing skin for years and believes that the technology could be game-changing in the medical industry, enabling the production of skin grafts that closely mimic natural skin.
“Right now, whatever is available as a clinical product is more like a fancy Band-Aid,” explained Karande. “It provides some accelerated wound healing, but eventually it just falls off; it never really integrates with the host cells.”
The ability to print skin tissue with integrated blood vessels could change that and offer a viable solution to grafts that biointegrate into the patient’s body.
Building on research
In his previous work, Karande was one of the first to demonstrate that it was possible to take two types of living human cells, transform them into bioinks and print them into a skin-like structure. From there, Karande and his team started working with a team from the Yale School of Medicine to explore the possibility of integrating blood vessels into the tissue.
The new study has made headway on this front by adding key ingredients, such as human endothelial cells (cells that line the inside of blood vessels) and human pericyte cells (which wrap around the endothelial cells). When combined with animal collagen and other structural cells found in skin grafts, these cells begin to communicate and form a “biologically relevant vascular structure” within just a few weeks.
As Karande explained: ”As engineers working to recreate biology, we’ve always appreciated and been aware of the fact that biology is far more complex than the simple systems we make in the lab. “We were pleasantly surprised to find that, once we start approaching that complexity, biology takes over and starts getting closer and closer to what exists in nature.”
The bioprinted skin sample was grafted by Yale researchers onto a special type of mouse to see what would happen. As the researchers hoped, the vessels from the printed skin began to communicate with the mouse’s blood vessels, indicating that a transfer of blood and nutrients to keep the graft alive was possible.
However, there is still lots of work to be done before the 3D bioprinted skin grafts are viable at a clinical level. For one, the researchers will need the ability to edit the donor cells so that they are accepted by the patient’s body and can be integrated seamlessly. That will be the next big step in the research.
“This significant development highlights the vast potential of 3D bioprinting in precision medicine, where solutions can be tailored to specific situations and eventually to individuals,” said Deepak Vashishth, the director CBIS. “This is a perfect example of how engineers at Rensselaer are solving challenges related to human health.”
Down the line, the bioprinted skin tissue could be used to help patient’s suffering from “discrete issues” such as diabetic or pressure ulcers. More severe cases, like burn victims, will need a bit more work, as researchers need to address nerve and vascular damage.
“For patients [with discrete issues], these would be perfect, because ulcers usually appear at distinct locations on the body and can be addressed with smaller pieces of skin,” Karande concluded. “Wound healing typically takes longer in diabetic patients, and this could also help to accelerate that process.”