On‐Demand Operando Embolization by Rapid Sonodynamic Gelation of Liquid Metal‐Embedded Hydrogels for Effective and Durable Tumor Treatment

Transcatheter arterial embolization (TAE) has been clinically approved as an effective and minimally invasive treatment for hypervascular tumors. However, the available embolic TAE agents usually face notable limitations and sometimes fatal risks, including embolism displacement, recanalization, and toxicity, among others. Therefore, the development of injectable and biosafe hydrogels for operando embolization represents an alternative smart route to solve the critical TAE agent problems, although tremendous challenges still exist. Here, we report a biocompatible liquid metal microsphere-embedded hydrogel, which is sensitive to ultrasound to operando induce gelation and crosslinking in a short time and small intravascular spaces. By this strategy, the Gallium microspheres (GaMSs) serve multiple roles, including as a sonodynamic catalyst for fast gelation, sustained Ga ion release to form a secondary crosslinking structure and a tough hydrogel, as well as a better radiopaque agent. This TAE agent demonstrates excellent on-demand embolization performances with superior mechanical properties, biocompatibility, radiopacity, and remarkable spatiotemporal responses, offering a promising TAE solution for effective and durable tumor treatments with no occurrences of any ectopic embolization or recanalization.