Research of novel biocompatible radiopaque microcapsules for arterial embolization.

Embolic agents, such as microparticles, microspheres or beads used in current embolotherapy are mostly radiolucent, which means the agents are invisible under X-ray imaging during and after the process of embolization, and the fate of these particles cannot be precisely assessed. In this research, a radiopaque embolic agent was developed by encapsulating lipiodol in polyvinyl alcohol. The lipiodol-containing polyvinyl alcohol microcapsules (LPMs) were characterized and evaluated for their morphology, size distribution, lipiodol content, lipiodol release, elasticity, and deliverability through catheter. The radiopacity of LPMs in vials and in living mice was both detected by an X-ray imaging system. The biocompatibility of LPMs was investigated with L929 cells and in mice after subcutaneous injection. Embolization of LPMs to a rabbit kidney was performed under digital subtraction angiography (DSA) and the radiopacity of LPMs was verified by computed tomography (CT).