| abstract |
A medical device ( 10 ) includes a structure ( 12 ) adapted for introduction into a patient, the structure ( 12 ) being formed of a preferably non-porous base material ( 14 ) having a roughened or textured surface ( 16 ). The structure ( 12 ) is conveniently configured as a vascular stent with a base material ( 14 ) of stainless steel, nitinol or another suitable material. The medical device ( 10 ) also includes a layer ( 18 ) of a bioactive material posited directly upon the roughened or textured surface ( 16 ) of the base material ( 14 ) of the structure ( 12 ). The surface ( 16 ) of the base material ( 14 ) is roughened or textured by etching or by abrasion with sodium bicarbonate or another suitable grit. A preferred roughened or textured surface ( 16 ) is thought to have a mean surface roughness of about 10 μin. (about 250 nm) and a surface roughness range between about 1 μin. and about 100 μin. (about 25 nm and about 2.5 μm). The particularly preferred use of sodium bicarbonate as the abrasive to provide roughness or texture to the surface ( 16 ) of the base material ( 14 ) of the structure ( 12 ) is additionally advantageous in the low toxicity of the sodium bicarbonate to production workers, the ease of product and waste cleanup, and the biocompatibility of any residual sodium bicarbonate. |