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

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.