Studies on radio-opaque polymeric biomaterials with potential applications to endovascular prostheses.

A new polymeric biomaterial, which uniquely combines radio-opacity (X-ray visibility) and low thrombogenicity, is described. First, preparation, purification, and identification of the essential monomeric building block, 2-[2'-iodobenzoyl]-ethyl methacrylate (3), are outlined. Second, [Figure: See text] the synthesis of the biomaterial, a terpolymer with composition MMA: HEMA: 3 = 65:15:20 (mole/mole/mole) is described. Third, the physico-chemical characteristics of the polymer (e.g. NMR spectroscopy, thermal behaviour) are given. Fourth, the in vitro thrombogenicity of the material was characterized by means of recent test assay. The combined results reveal that the terpolymer is very suitable for prosthetic applications in the cardiovascular system. A new prototype of an endovascular stent, made from the terpolymer, is presented. Stents find clinical use in interventional cardiology, in conjunction with percutaneous transluminal coronary angioplasty (PTCA). It is put forward that the stent prototype presented herein has, at least in principle, some advantages over existing (metallic) stents; these advantages are primarily owing to the unique combination of X-ray visibility and haemocompatibility which is presently achieved.