Thermal stabilization of diverse biologics using reversible hydrogels.

Improving the thermal stability of biologics, including vaccines, is critical to reduce the economic costs and health risks associated with the cold chain. Here, we designed a versatile, safe, and easy-to-use reversible PEG-based hydrogel platform formed via dynamic covalent boronic ester cross-linking for the encapsulation, stabilization, and on-demand release of biologics. Using these reversible hydrogels, we thermally stabilized a wide range of biologics up to 65°C, including model enzymes, heat-sensitive clinical diagnostic enzymes (DNA gyrase and topoisomerase I), protein-based vaccines (H5N1 hemagglutinin), and whole viruses (adenovirus type 5). Our data support a generalized protection mechanism for the thermal stabilization of diverse biologics using direct encapsulation in reversible hydrogels. Furthermore, preliminary toxicology data suggest that the components of our hydrogel are safe for in vivo use. Our reversible hydrogel platform offers a simple material solution to mitigate the costs and risks associated with reliance on a continuous cold chain for biologic transport and storage.