Novel Vascular-Adaptive Liquid Metal Microspheres Enable Visualized Arterial Embolization Therapy

Arterial embolization therapy is a promising strategy for treating both malignant and benign tumors. However, conventional embolic agents often lack inherent radiopacity and have limited embolizing ability, resulting in difficulty in real-time monitoring during arterial embolization, low postoperative tumor necrosis rate, and high risk of recurrence. In this study, we prepared a liquid metal microsphere with radiopacity by disrupting the surface tension of liquid gallium via ultrasonication. These microspheres have a self-limiting oxide layer on their surface, while their core remains liquid. Drug loading can be achieved by modifying the surface of liquid metal microspheres, and the drug-loaded microspheres are named X-MEN. Owing to their unique physical structure, these liquid metal microspheres exhibit excellent fluidity, viscoelasticity, and deformability. This enables them to navigate through microcatheters and conform tightly to the vessel wall, achieving efficient embolization. These microspheres can remain stable in the target vessel for at least six months, with no observed recanalization. In addition, the radiopacity of these microspheres allows for real-time monitoring during arterial embolization, thereby enabling precise control over the embolization process. Therefore, liquid metal microspheres are a very promising long-acting embolic agent for image-guided arterial embolization.