X-ray Visible and Uniform Alginate Microspheres Loaded with in Situ Synthesized BaSO₄ Nanoparticles for in Vivo Transcatheter Arterial Embolization

The lack of noninvasive tracking and mapping the fate of embolic agents has restricted the development and further applications of the transcatheter arterial embolization (TAE) therapy. In this work, inherent radiopaque embolic material, barium alginate (ALG) microspheres loaded with in situ synthesized BaSO₄ (denoted as BaSO₄/ALG microspheres), have been synthesized by a one-step droplet microfluidic technique. One of the advantages of our microfluidic approach is that radiopaque BaSO₄ is in the form of nanoparticles and well dispersed inside ALG microspheres, thereby greatly enhancing the imaging quality. The crystal structure of in situ synthesized BaSO₄ nanoparticles in ALG microspheres is confirmed by X-ray diffraction analysis. Results of in vitro and in vivo assays from digital subtraction angiography and computed tomography scans demonstrate that BaSO₄/ALG microspheres possess excellent visibility under X-ray. Histopathological analysis verifies that the embolic efficacy of BaSO₄/ALG microspheres is similar to that of commercially available alginate microsphere embolic agents. Furthermore, the visibility of radiopaque BaSO₄/ALG microspheres under X-ray promises the direct detection of the embolic efficiency and position of embolic microspheres after embolism, which offers great promises in direct real-time in vivo investigations for TAE. (Figure Presented).