Self-healing hydrogels

Ligand (biochemistry)

Receptor

Nanotechnology

Organic chemistry

Covalent bond

Polymer chemistry

Combinatorial chemistry

Bipyridine

Crystal structure

Metal ions in aqueous solution

Self-assembly

Chemistry

Materials science

Chelation

Metal

Coordination complex

Terpyridine

Biochemistry

Macromolecular Rapid Communications

Self‐healing hydrogels based on metal–ligand coordination chemistry provide new and exciting properties that improve injectability, rheological behaviors, and even biological functionalities. The inherent reversibility of coordination bonds improves on the covalent cross‐linking employed previously, allowing for the preparation of completely self‐healing hydrogels. In this article, recent advances in the development of this class of hydrogels are summarized and their applications in biology and medicine are discussed. Various chelating ligands such as bisphosphonate, catechol, histidine, thiolate, carboxylate, pyridines (including bipyridine and terpyridine), and iminodiacetate conjugated onto polymeric backbones, as well as the chelated metal ions and metal ions containing inorganic particles, which are used to form dynamic networks, are highlighted. This article provides general ideas and methods for the design of self‐healing hydrogel biomaterials based on coordination chemistry.

Self‐Healing Polymeric Hydrogel Formed by Metal–Ligand Coordination Assembly: Design, Fabrication, and Biomedical Applications