Fabrication and Properties of Anti-freezing Gelatin Hydrogels Based on a Deep Eutectic Solvent

In this study, gelatin hydrogels with excellent anti-freezing properties were prepared by simply immersing the initial hydrogels in a deep eutectic solvent (DES) aqueous solution. The formation of ice crystals in hydrogels is greatly hindered by introduction of the DES even at very low temperatures. The hydrogels still remain mechanically flexible even at −80 °C. In addition, the DES could facilitate the protein chain bundling, resulting in the formation of triple helices and thus improving the mechanical properties of gelatin hydrogels. Furthermore, the hydrogels could be stored for a long time with slight water loss, thus showing good water retention performance.