Scientists at Cornell University have created a new material that could improve how mRNA vaccines work by making them safer and more efficient.
This discovery might not only boost current vaccines but also help develop powerful new ones, such as cancer vaccines.
mRNA vaccines, like those used against COVID-19, work by teaching our cells to make proteins that help the immune system recognize and fight viruses.
To protect the fragile mRNA and help it reach the cells, it’s packaged in tiny fat bubbles called lipid nanoparticles.
These nanoparticles often include a chemical called polyethylene glycol (PEG), which helps the vaccine slip past the immune system.
However, PEG can also cause immune reactions in some people.
That’s because many of us have already developed antibodies against PEG from using common products like shampoo and toothpaste that contain it.
So, when PEG is in a vaccine, the immune system may attack it, reducing the vaccine’s effectiveness and sometimes causing side effects.
To solve this problem, Professor Shaoyi Jiang, a biomedical engineer at Cornell, has developed a new alternative to PEG using a material called poly(carboxybetaine), or PCB for short. PCB is a type of “zwitterion,” a molecule that attracts water and blends easily into the body.
This super-hydrophilic quality helps it avoid being noticed by the immune system while still doing the job of protecting the mRNA.
Jiang’s research, published in Nature Materials, shows that replacing PEG with PCB creates a better delivery system for mRNA vaccines. The new nanoparticles are more stable, avoid unwanted immune responses, and still deliver the vaccine effectively into cells.
This improvement is especially important for developing mRNA-based cancer vaccines. Unlike COVID-19 vaccines, which require only a small dose, cancer vaccines need to deliver a much larger amount of mRNA because tumors tend to suppress the immune system.
That means any side effects or immune reactions from PEG would be even more serious. The new PCB-based nanoparticles solve this problem by staying “invisible” to the immune system, reducing side effects while boosting the immune response where it’s needed.
Jiang is now working with hospitals and research centers in the U.S. and Canada to move this breakthrough closer to real-world use, especially in cancer treatment. This new “stealth” material could mark the next big step for mRNA vaccines.
