Scientists have created a microneedle "vaccine patch" that promises to boost immune response. It is much more effective than traditional vaccine shots, and it does not cause anxiety or pain like conventional needles.
Although microneedle patches are a long-standing development, it has been difficult to scale up production. It can also be difficult to adapt the same microneedle patch for different vaccine types.
These problems are solved by a new 3D-printing method called continuous liquid interface manufacturing or CLIP. It uses ultraviolet light and a special resin, to create patches that are uniform in size, shape and spacing regardless of how many are produced.
"Our approach allows us directly to 3D-print microneedles. This gives us lots of design flexibility for making the best microneedles in terms of performance and cost," said Shaomin Tian, a microbiologist at the University of North Carolina Chapel Hill.
Researchers believe that the microneedle patches could be more widely used because of their speed and ease of development. These patches are able to be administered by themselves, so you don't need to make an appointment with a physician or nurse.
The reason is that the needles are only required to reach the surface of the skin (transdermal) and not the entire depth (subcutaneous), as traditional vaccines.
The drug is delivered directly to the skin immune cells. This makes it ideal for vaccines. It is possible to lower dosages with a more efficient delivery method.
The researchers discovered that the patch produced a T-cell response and an antigen-specific antibody response in mice. This was 50 times higher than the traditional subcutaneous injection.
The researchers explained in their paper that 3D-printed microneedles delivery of vaccine components resulted in improved cargo retention, activation and immune cell responses, as well as more powerful humoral and cellular immune reactions.
According to the team, its approach and design can be modified to include vaccines for measles and flu as well as COVID-19. It doesn't require refrigeration or special handling in transport, which could increase vaccination rates. You can combine multiple drugs with the patches thanks to recent advances in the field.
Although the patch has not been tested on humans yet, it is expected to have similar benefits to those seen in mice. This will allow for faster and more efficient vaccinations against future pandemics and epidemics.
Researchers aren't content with just one microneedle vaccine, but they are looking into how RNA vaccines, including the Moderna COVID-19 and Pfizer vaccines, might be incorporated into their next design.
"In developing this technology we hope to set up the foundation for even faster global development of vaccines at lower doses in a pain- and anxiety-free way," said Joseph DeSimone, a chemical engineer from Stanford University.
The research was published in PNAS.