Well‐Defined Poly(ethylene glycol) Hydrogels with Enhanced Mechanical Performance Prepared by Thermally Induced Copper‐Catalyzed Azide–Alkyne Cycloaddition

Poly(ethylene glycol) (PEG)‐based hydrogels have attracted increasing attention in recent years due to their good biocompatibility and low cost. However, the PEG‐based hydrogels prepared by traditional methods exhibit a poor machinability due to their disordered network structure. Herein, the preparation of well‐defined PEG‐based hydrogel via a facile thermally induced copper‐catalyzed azide–alkyne cycloaddition (CuAAC) reaction is demonstrated. To accomplish this, thermochemically reduced Cu(I) catalyst is adopted to trigger “click” cross‐linking, resulting in a well‐defined PEG network. The as‐synthesized PEG‐based hydrogel exhibits good mechanical performance with a tensile strength of 2.51 MPa, which is higher than the traditional PEG‐based hydrogels prepared from CuSO 4 /NaSac‐mediated or CuBr/ligand‐catalyzed CuAAC. Moreover, in vitro cytotoxicity and in vivo porcine subcutaneous implantation tests demonstrate that the as‐synthesized PEG‐based hydrogel has a good biocompatibility and low toxicity, making it a promising candidate for the applications in biomedical devices and tissue engineering.