Buzzworthy 3D ‘Skin Printer’ Grew from Minnesota-Funded Stem Cell Program
When the University of Minnesota announced in April it had achieved a technological breakthrough by printing an electronic circuit directly onto the skin of a human hand, it made international news as readers and media viewers around the globe pondered its implications.
Among those were the possibility that soldiers could use a low-cost, portable 3D printer on the battlefield as a way to print bio-weapons sensors, solar-powered battery rechargers or many other kinds of electronic applications directly onto their skin, then peel or wash them off afterwards.
“We are excited about the potential of this new 3D-printing technology using a portable, lightweight printer costing less than $400,” co-inventor Michael McAlpine, a U of M mechanical engineering associate professor, said in the April 25 announcement. “We imagine that a soldier could pull this printer out of a backpack and print a chemical sensor or other electronics they need, directly on the skin. It would be like a 'Swiss Army knife' of the future with everything they need all in one portable 3D printing tool.”
The new printer, McAlpine added, also has a medical application – it has proven capable of printing out skin cells to repair wounds in tests on mice.
While the novelty of the idea drew attention from media outlets such as Britain’s Independent, The Hindu in India and a host of tech news websites, what wasn’t so widely reported was that the funding for the study which produced the 3D skin printer was in part supplied by Regenerative Medicine Minnesota (RMM), a state-funded research collaboration between the U of M and the Mayo Clinic meant to advance the state’s emerging stem cell industry.
The collaboration was set up 2014 when the Minnesota Legislature provided about $4.5 million a year for 10 years for stem cell research and education throughout the state. Its goals are to create “an educated public and a specialized workforce”; develop an “environment to attract and support biotechnology industry”; build the infrastructure to deliver new medical therapies; and ultimately, bring those discoveries and new treatments to Minnesotans throughout the state.
This avenue of stem cell research is where McAlpine got his start on the now-famous “skin circuit” printer.
His $250,000 RMM grant for 2017-19 is for developing a way to use 3D printing to deploy stem cells in repairing damaged heart tissues and vessels. The ultimate goal is to cut down on the need for organ transplants.
The innovation is the creation of a “4D printed” system to deliver biochemicals capable of instructing undifferentiated, or “pluripotent,” stem cells where to go, when to grow, and what kind of cells to develop into. In this way, they can regenerate specific kinds of tissues in the heart in an orchestrated way.
As part of the RMM-funded effort, U of M Medical School officials say this 4D printing technology can create “nanocapsules” capable of releasing molecules on cue, much as human cells would, to initiate a biological or other chemical response.
It works by first printing a fine-grained hydrogel mesh embedded with pluripotent stem cells and signaling molecules, then placing the mix into nanocapsules coated with a gold-bearing polymer. When the gold particles are heated with laser light, they trigger an effect — the signaling molecules direct some of the stem cells to turn into cardiac muscle cells, while others differentiate into cardiac blood vessels.