MIT researchers are touting microparticles that can deliver payloads at different points, potentially creating “self-boosting” vaccines.

A new study, highlighted on the institute’s news website, demonstrates a way in which researchers could design vaccines that would need to be given just once before they “self-boost,” or essentially re-deliver the therapeutic, at a specified point in the future. The particles can remain under the skin until the vaccine is released, then break down like resorbable sutures.

Such vaccine delivery could be useful for childhood vaccinations in regions where people don’t have frequent access to medical care, according to the researchers.

“This is a platform that can be broadly applicable to all types of vaccines, including recombinant protein-based vaccines, DNA-based vaccines, even RNA-based vaccines,” Ana Jaklenec, a research scientist at MIT’s Koch Institute for Integrative Cancer Research, said on the MIT website. “Understanding the process of how the vaccines are released, which is what we described in this paper, has allowed us to work on formulations that address some of the instability that could be induced over time.”

Jaklenec and Robert Langer, the David H. Koch Institute Professor at MIT and a member of the Koch Institute, are the senior authors of the new study, which was published in Science Advances. Morteza Sarmadi, a research specialist at the Koch Institute and recent MIT PhD recipient, was the lead author of the paper.

The researchers also say the method could be used to deliver other therapeutics, like cancer drugs, hormone therapy and biologic drugs.

Resembling tiny coffee cups, the particles were formed through the creation of arrays of silicon molds used to shape PLGA (a biocompatible polymer that has already been approved for use in medical devices such as implants, sutures, and prosthetic devices) cups and lids. The researchers then placed a custom-built, automated dispensing system to fill each cup with a drug or vaccine, after which point the lids are aligned and lowered on the cups and the system is heated slightly until the cup and lid fuse together to seal the drug inside.

The method, called SEAL (StampEd Assembly of polymer Layers), can be used to produce particles of any shape or size, the researchers say. They found that the particles can release their payload at different times based on the differences in composition of the polymer and chemical groups attached at the ends of the polymers.

“If you want the particle to release after six months for a certain application, we use the corresponding polymer, or if we want it to release after two days, we use another polymer,” Sarmadi said. “A broad range of applications can benefit from this observation.”