Advances on the use of carbon based materials at the biological and surface interface for applications in medical implants

One of the setbacks of vascular stents is the potential development of a thick-smooth muscle tissue inside the lumen, which can be so severe as to re-occlude the vessel lumen leading to restenosis. Considerable improvements have been made, including the use of more bio-compatible materials, anti-inflammatory drug-eluting stents, re-sorbable stents, and now plasma coatings are being recognised as a potential way forward. This paper describes the role of 3-D plasma coatings of amorphous carbon and in particular low-stress a-C:H:Si overlayers. The high barrier nature of the amorphous carbon coating is examined by measuring oxygen and water diffusion across the ultra thin film. The stent coating is analysed by Raman Spectroscopy and the ID/IG ratio relates to the coating quality differences inside and outside of the stent cage. Published by Elsevier B.V.