Solvent Exchange Induced In Situ Formed Hydrogel as Liquid Embolic Agents

Endovascular embolization can selectively deploy embolic agents into diseased or injured blood vessels to complete the treatment. However, traditional embolic agents still face challenges, such as poor intravascular diffusivity, non-biodegradable, unstable mechanical properties, radiolucency, and recanalization. Herein,  we report a poly (lipoic acid-tannic acid)/tromethamine/Galinstan (PLTTG) dimethyl sulfoxide (DMSO) solution-derived hydrogel liquid embolic agent. By injecting PLTTG DMSO solution into body fluids, a PLTTG hydrogel can be formed in situ owing to the solvent exchange induced intra- and inter-polymer hydrogen bonding and electrostatic interactions. Moreover, the gelation time and injection forces of the solution as well as the mechanical properties and embolic pressure of the obtained hydrogels can be adjusted by changing the concentration of PLTTG. The PLTTG hydrogel can effectively embolize the renal artery and femoral vein without recanalization and displacement in rabbit models. Furthermore, the hydrogel can embolize the ruptured femoral artery to arrest active bleeding. Owing to the advantages of the hydrogel, including adjustable gelation time, mechanical properties, viscosities, injection forces, and embolic pressure, as well as good biocompatibility and biodegradability, radiopacity, excellent embolization performance and intravascular diffusivity, easy usage, low cost, allowing it to be a potential embolic agent to treat multiple vascular diseases in clinic.