3D-printed microneedle patches offer greater immunity than single needles

The ease and effectiveness of a vaccine patch sets the course for a new way to deliver vaccines that’s painless, less invasive than a shot, does not require cold storage, and can be self-administered. UNC-Chapel Hill

Scientists at Stanford University and the University of North Carolina at Chapel Hill have developed a 3D-printed vaccine patch that reportedly provides greater protection than a typical vaccine shot. The immunity response from the vaccine patch was 10 times greater than vaccine delivered into an arm muscle with a needle jab, according to a study conducted with animals and published in the Proceedings of the National Academy of Sciences.

“In developing this technology, we hope to set the foundation for even more rapid global development of vaccines, at lower doses, in a pain- and anxiety-free manner,” said study author and entrepreneur Joseph M. DeSimone, professor of translational medicine and chemical engineering at Stanford University and professor emeritus at UNC-Chapel Hill. (DeSimone is co-founder, board chair, and the former CEO of the additive manufacturing company Carbon.)

It’s generally a challenge to adapt microneedles to different vaccine types, said study author Shaomin Tian, researcher in the Department of Microbiology and Immunology in the UNC School of Medicine. “These issues, coupled with manufacturing challenges, have arguably held back the field of microneedles for vaccine delivery,” she said.

Most microneedles are fabricated with master templates to make molds. However, the molding of microneedles is not very versatile, and drawbacks include reduced needle sharpness during replication.

“Our approach allows us to directly 3D-print the microneedles, which gives us lots of design latitude for making the best microneedles from a performance and cost point of view,” Tian said. The microneedles were produced at UNC-Chapel Hill using a CLIP prototype 3D printer that DeSimone invented and is produced by Carbon.

The team of microbiologists and chemical engineers is continuing to innovate by formulating RNA vaccines, like the Pfizer and Moderna COVID-19 vaccines, into microneedle patches for future testing.

“One of the biggest lessons we’ve learned during the pandemic is that innovation in science and technology can make or break a global response,” DeSimone said. “Thankfully, we have biotech and health care workers pushing the envelope for us all.”

Additional study authors include Cassie Caudill, Jillian L. Perry, Kimon lliadis, Addis T. Tessema, and Beverly S. Mecham of UNC-Chapel Hill, and Brian J. Lee of Stanford.