Mucus‐Inspired Drug‐Loaded Bottlebrush Polymer Hydrogel With Easy‐Removable and Shear‐Thinning Characteristics Enables Effective Treatment of Persistent Root Canal Infection

Existing hydrogels pose challenges for the applications in transitional medication within narrow cavities due to the inherent conflict between fluidity and shape retention. Herein, inspired by mucus, a bottlebrush polymer hydrogel (denoted as PH‐PG‐T hydrogel) with excellent injectability, stable antibacterial property, and easy removability is developed by grafting poly(ethylene glycol) methyl ether methacrylate side‐chains from polyhydroxyethyl methacrylate backbones and incorporating triple antibiotics. As a transitional disinfectant in tooth root canal treatment, PH‐PG‐T hydrogel fulfills requirements for an ideal disinfectant thorough treatment process. The polymer side‐chains of PH‐PG‐T hydrogel disentangle during injection to facilitate canal filling and rapidly re‐entangle after injection to enable in situ gelation and sustained antibiotics release. After medication, PH‐PG‐T hydrogel quickly dissolves in water during irrigation, facilitating its complete removal from the root canal. These findings highlight a promising avenue for the novel application of bottlebrush polymers as a high‐performance disinfectant to control persistent root canal infections.