LAUSR

Hydrogels are three-dimensional network structures composed of physically- or chemically-crosslinked, hydrophilic molecules. Compared with conventional hydrogels with static and permanent network structures, injectable and responsive hydrogels generated from dynamic networks, have attracted increasing attention from various disciplines due to their wide-ranging applications in tissue engineering, drug delivery, soft robotics, etc. Herein, we developed an injectable self-healing and multiple-responsive hyaluronic acid (HA)- histamine (His)/metal hydrogel by modifying His onto HA and the subsequent, dynamic coordination between imidazole and metal ions. The pH-responsive and mechanical behaviors exhibited by the HA-His/metal hydrogels were tunable with the kinds and concentrations of metal ions. The HA-His/Zr4+ hydrogels demonstrated a moldable capability at a neutral pH and a multistimulus-responsive capability when exposed to a weak alkaline environment and hyaluronidase, which inhibited bacterial growth and biofilm formation. Biocompatibilities and accelerated wound healing were demonstrated in vitro and in vivo and were thoroughly investigated and well characterized. We believe that the HA-His/Zr4+ hydrogel has great potential in various biomedical applications, such as pH- and hyaluronidase-responsive sustained release, antibacterial, and implantable materials for tissue engineering. This article is protected by copyright. All rights reserved.