New Intrinsically Radiopaque Hydrophilic Microspheres for Embolization: Synthesis and Characterization

Centre for Biomaterials Research, Faculty of Health, Medicine and Life Sciences, University of Maastricht, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
Biomacromolecules (Impact Factor: 5.75). 02/2008; 9(1):84-90. DOI: 10.1021/bm7008334
Source: PubMed


Polymeric particles currently used for embolization procedures have the disadvantage that they are radiolucent, that is, invisible on X-ray images, and consequently the interventional radiologist has to resort to angiography to (indirectly) monitor the fate of the particles. Here, we introduce intrinsically radiopaque hydrophilic microspheres. Since these microspheres can directly be visualized on X-ray images, using these microspheres for embolization purposes will allow superprecise location of the embolic material, both during and after the procedure. The microspheres, which are prepared by suspension polymerization, are based on the radiopaque monomer 2-[4-iodobenzoyl]-oxo-ethylmethacrylate and hydroxyethylmethacrylate (HEMA) and/or 1-vinyl-2-pyrrolidinone (NVP) as hydrophilic component. It has been shown that for clinically relevant X-ray visibility the spheres should contain at least 20 wt % iodine. At this iodine content, copolymerization with HEMA results in spheres that hardly imbibe water (EQ = 1.08). When HEMA is replaced by NVP, the volume swelling ratio can be significantly increased (to 1.33).

Download full-text


Available from: Leo H. Koole
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Last years, calibrated microspheres have proven their superiority in targeting embolization over non spherical particles in many applications. For the very near future they represent the best tool for controlling drug delivery in chemoembolization, under the two conditions that they would be image detectable and that the "dosimetry" would be tailored to pathological process.
    Full-text · Article · Jan 2008 · Techniques in Vascular and Interventional Radiology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Synthetic polymeric microspheres find application in a wide range of medical applications. Among other applications, microspheres are being used as bulking agents, embolic- or drug-delivery particles. The exact composition of the spheres varies with the application and therefore a large array of materials has been used to produce microspheres. In this review, the relation between microsphere synthesis and application is discussed for a number of microspheres that are used for different treatment strategies.
    Full-text · Article · Jun 2010 · Materials
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Core P(MAOETIB-GMA) microparticles of 40-200 microm were prepared by suspension copolymerization of the iodinated monomer 2-methacryloyloxyethyl (2,3,5-triiodobenzoate), MAOETIB, with a low concentration of the monomer glycidyl methacrylate, GMA, which formed hydrophilic surfaces on the particles. Magnetic gamma-Fe(2)O(3)/P(MAOETIB-GMA) core-shell microparticles were prepared by coating the aforementioned core particles through nucleation of iron oxide nanoparticles on the surfaces of the P(MAOETIB-GMA) particles. This was followed by stepwise growth of thin iron oxide layers. The radiopacity and magnetism of these particles were demonstrated in vitro by CT and MRI. In vivo embolization capabilities of these first multimodal visible embolization particles were demonstrated in a rat's kidney tumor embolization model.
    Full-text · Article · Jun 2010 · Biomacromolecules
Show more