Metal-Polyphenol Nanoshell for Enhancing the Thermostability of Single Viral Vaccine

Vaccines are essential to prevent infectious diseases, but their thermal instability leads to their heavy reliance on cold-chain. Physical encapsulation is the simplest and most effective strategy to increase the thermostability of vaccines. However, traditional mineralized coatings are strictly dependent on the properties of substrate surface and synthesis conditions. Considering the instability and low surface charge density of vaccines, we developed a facile and robust approach for the protection of a single viral vaccine, tobacco mosaic virus (TMV), through tannic (TA) and FeIII metal-polyphenol networks, which significantly improved the thermostability of viral vaccine by strengthening its conformational rigidity. We found that the formed TA-FeIII nanoshell drastically enhanced the thermostability of the viral vaccine at high temperature of 100 °C and long-term storage at 37 °C. Additionally, the TA-FeIII nanoshell did not destroy the viral RNA, had excellent biocompatibility and was easily synthesized on the vaccine surface within seconds. This ease, low cost and substrate-independent approach makes TA-FeIII nanoshell as a potential candidate for vaccine applications.