Hofmeister Effect‐Assisted Strong Natural Biopolymer‐Based Hydrogels with Multi‐Functions

Main observation and conclusion Natural biopolymer‐based hydrogels have been extensively studied in recent years due to their excellent biocompatibility. However, the preparation of multi‐functional and tough natural biopolymer‐based hydrogels is still a challenging problem. Herein, a natural biopolymer‐based hydrogel is prepared using gelatin and carboxymethyl chitosan (CMCS) through a one‐step soaking method. The prepared hydrogel without any synthetic polymers and crosslinking agents has a fully physical crosslinking structure. Due to the hydrophobic interaction brought by the Hofmeister effect, the mechanical properties of soaked hydrogels (tensile stress and strain can reach 3.77 MPa and 1082%) are superior to conventional protein hydrogels. In addition, the prepared gelatin/carboxymethyl chitosan (Gel/CMCS) hydrogels exhibit a variety of appealing properties, including good shape memory, fatigue resistance, electrical conductivity, water retention, drug releasing, antibacterial property, and recyclability. This strategy opens up a new horizon to fabricate hydrogels with excellent mechanical properties and multiple functions, which can extend their applications in the biomedicine area and other related fields.