Researchers develop new silk-based stabilizer for vaccines and antibiotics

To test their new silk stabilizers, Kaplan's team stored the measles, mumps, and rubella (MMR) vaccines for six months at the recommended 39.2 degrees Fahrenheit, as well as at 77, 98.6 , and 113 degrees Fahrenheit. The results show that encapsulation in the new silk films maintained the potency with minimal loss over time and enhanced stability, even at very high storage temperatures. Similarly, antibiotics entrapped in silk films maintained near optimal activity even at temperatures as high as 140 degrees. In addition, Kaplan's group found that these silk films had the added benefit of protecting one antibiotic against the detrimental effects of light exposure.

The silk stabilizers are likely to combine well with Kaplan's previously developed silk microneedle system. These tiny needles can deliver medication directly to skin cells that contain a specified antigen. This targeted approach permits administration of lower doses of medication or vaccine and generates longer-lasting immune responses. The combination could prove to be a simple way to stabilize, distribute, and deliver the medication in one system.

Thus, for vaccines and antibiotics, the use of a silk carrier reduces the detrimental effects of heat and humidity.

"New studies are already under way," says Dr. Kaplan. "We have already begun trying to broaden the impact of what we're doing to apply to all vaccines. Based on what we've seen with other proteins, peptides, and enzymes, there's no reason to believe that this wouldn't be universal. This could potentially eliminate the need for a cold-chain system, greatly decreasing costs and enabling more widespread availability of these life-saving drugs."  

Source: NIH/National Institute of Biomedical Imaging & Bioengineering