Kiran, SSunny, MCJoseph, R2017-03-102017-03-10201766 ,5;213-22010.1080/00914037.2016.1201764https://dspace.sctimst.ac.in/handle/123456789/9943In this work synthesis and characterization of inherently X-ray opaque, nonresorbable polyurethane microspheres with well-calibrated particles in a defined range of sizes suitable for embolization is reported. In order to impart X-ray opacity to the polyurethane, a bifunctional monomer, namely, 4,4-isopropylidenediphenol (BPA) was iodinated and this iodinated compound was used as one of the monomers during polyurethane synthesis. The resultant X-ray opaque polyurethane was converted into microspheres using an oil-in-water emulsion and solvent evaporation technique. Microspheres obtained had diameters in the range of 200-500 mu m, were noncytotoxic and free from X-ray attenuating additives. In vivo X-ray fluoroscopic imaging carried out in a rabbit cadaver model showed that these microspheres were sufficiently X-ray opaque to be visualized under fluoroscopic conditions. [GRAPHICS] .Materials Science; Polymer Science