Microneedle Vaccine Patches Offer Potent, Cost-Effective Protection
Researchers at Stanford University and the University of North Carolina Chapel Hill have developed a 3D-printed vaccine patch that activates improved immune cell activation in comparison to traditional methods.
Researchers discovered the immune response the patches stimulated was 10 times stronger than immunizations delivered to mice with a hypodermic, according to a study published in the Proceedings of the National Academy of Sciences. The microneedles are about 700 micrometers in length and deliver the vaccination after being placed in a solution-filled coating vessel, held for 10 seconds, removed and allowed to air dry.
“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,” Joseph DeSimone, professor of Translational Medicine and Chemical Engineering at Stanford University and professor emeritus at UNC-Chapel Hill, said in a written statement. “Thankfully, we had biotech and health care workers pushing the envelope for all of us. In developing this technology, we hope to set the foundation for even more rapid global deployment of vaccines, at lower doses, in a pain- and anxiety-free manner, providing greater access to vaccines for all.”
The needles were printed using a technique known as continuous liquid interface production, or “CLIP.” Transdermal delivery by the microneedles resulted not only in enhanced retention in the skin but also improved immune cell activation in the lymph nodes.
No cold storage is necessary for the patches and reducing the amount of synthetic DNA molecules by five times did not reduce antibody-mediated immunity. Further, the researchers discovered the microneedle vaccine exceeded all other forms of administration at each immunological dosage level.
“This not only makes a more cost-effective vaccination available but also helps to limit the potential antigen or adjuvant-induced side effects,” the text of the report read. “A similar dose-sparing effect was observed with intramuscular injections but not with the subcutaneous or ID vaccinations. On the other hand, at each antigen and adjuvant dosage level, the [microneedle] vaccine outperformed all routes of administration [intradermal, standard subcutaneous, and intramuscular] in the elicitation of humoral immunity.”
The faceted design of the patches resulted in greater surface area coverage compared to hypodermic needles, leading to a better coating of the vaccine components. Data analyzed by the researchers demonstrated the microneedle vaccine induced an immune response with higher and more balanced amounts of antibodies than traditional vaccine approaches.
With continued development, the microneedles patches can be used as a noninvasive and self-applicable vaccine alternative for patients. The patches can be used to deliver COVID-19 vaccinations as well other types, such as flu, measles and hepatitis vaccinations.
“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,” Shaomin Tian, lead study author and researcher in the Department of Microbiology and Immunology in the UNC School of Medicine, said in a press release on the report.
