Radiopaque polymeric materials for medical applications - Current aspects of biomaterial research

The aim of this review is to give an overview and some insight into differe nt radiopaque polymeric materials that are currently used as medical implan ts or inserts. The advantages and limitations of each radiopaque polymeric material are summarized. The main method used to make medical implants radi ologically visible is based on blending polymers with conventional radiopaq ue agents, blends which usually are a physical mixture of acrylic derivativ es and inorganic salts, Other methods reported involve either the formation of single-phase radiopaque polymer salt complexes somehow preventing the r elease of the radiopacifying element by entrapment of the complex in a cros slinked network, or radiopaque polymerized monomers characterized by a radi opacifying element associated with the monomer unit prior to polymerization , In the near future, research will certainly concentrate on biocompatible ra diopaque polymers,vith covalently bound opaque elements leading to stable p olymers with properties equivalent to the nonopaque, parent polymer.