Collagen (COL)−chitosan (CS) composite hydrogels are attracting increasing attention because of their great potential for application as biomaterials. However, conventional COL−CS hydrogels were easily disabled for lack of fully reversible linking in their networks. In this work, we developed a kind of self-healing hydrogel for wound dressing, composed of COL, CS, and dibenzaldehyde-modified PEG 2000 via dynamic imine bonds, and the COL/CS hydrogels showed good thermal stability, injectability, and pH sensitivity, ideally promoting wound-healing performance and hemostatic ability. Furthermore, the hydrogel could monitor multiple human motions, especially the facial expression via strain sensitivity. This work offers a new perspective for the biomass-based hydrogels applied in medical field as wound dressing.

Collagen‐based hydrogels have gained significant popularity in biomedical applications; however, traditional collagen hydrogels are easily disabled for lack of self‐healing properties due to their non‐reversible bonds. Here, a self‐healing collagen‐based hydrogel has been developed based on dynamic network chemistry, consisting of dynamic imine linkages between collagen and dialdehyde guar gum, as well as diol‐borate ester bonds between guar gum and borax. In addition, macromolecular interactions amongst macromolecules are involved. The above‐mentioned interactions were validated by Fourier transform infrared spectroscopy, sodium dodecyl sulfate polyacrylamide gel electrophoresis and DSC. The as‐prepared collagen‐based hydrogels showed good injectability and rapid self‐healing capacity (within 3 min) as reflected from injection tests, optical microscope observations, rheological measurements, as well as self‐healing studies. In addition, the collagen‐based hydrogels showed accelerated wound‐healing properties. This study offers a facile strategy to endow self‐healing ability on collagen‐based hydrogels without any external stimulus, which show great application potential as wound dressings. © 2020 Society of Chemical Industry

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