Silk Protein Preserves Drugs Without Refrigeration

Tufts University research shows that silk protein can be used to stabilize and maintain the potency of vaccines and other drugs that would otherwise need refrigeration. “Silk stabilization has the potential to significantly change the way we store and deliver pharmaceuticals, especially in the developing world,” said research-paper author and Tufts doctoral student, Jeney Zhang, in a press release.

Drugs can be loaded into silk fibroin, which contains nanoscale hydrophobic pockets that trap and immobilize bioactive biomolecules and protect them from moisture.  The silk can be made into films or other forms for non-refrigerated storage.

The Tufts researchers, led by David L. Kaplan, PhD, found that silk stabilization preserved the efficacy of the measles, mumps, and rubella (MMR) vaccine, as well as penicillin and tetracycline, significantly better than other options such as collagen encapsulants, dried powders, and solutions. The researchers found, for example, no activity loss for penicillin stored in silk films at 60 C for 30 days, compared with total activity loss within 24 h for penicillin stored in solution at the same temperature.

Kaplan’s lab also recently developed drug-infused microneedles made of silk, which are able to deliver precise amounts of drugs over time and without need for refrigeration. “This is an enormous added advantage that can potentially provide a lot of useful solutions to stabilization, distribution, and delivery,” said Kaplan in the release.

It will be interesting to see how this innovation is used and what other problems can be solved with silk.