CONICET | Buscador de Institutos y Recursos Humanos

P { margin-bottom: 0.21cm; } Cardiovascular stents are made of metal alloys and they are in contact with a corrosive biological environment. The corrosion may promote loss of material, subsequent fracture for the implant and the release of metallic ions that may induce platelet adhesion, hypersensitivity reactions and recurrent restenosis. Several coatings and metal alloys have been developed to improve this situation. Methodology: The corrosion resistance of commercial stents was evaluated using potentiometry technique. 316L stainless steel (naked, gold coated, graphite coated and with a surface treatment developed in our lab) and of Cr-Co alloy were tested. The resting potential as a function of time under open circuit and the corresponding polarimetric curve were determined. Micrographs were taken to follow the process. Results: The obtained curves, show that the anodic current density of the gold and graphite coated and surface treated stents are much lower than the anodic current density of naked stents. The Cr-Co stents, also presented a good behaviour, with low corrosion rates and a clear tendency to intergranular corrosion. The naked stainless steel showed the worse behaviour with pitting and mass loss. Conclusion: the coating and the surface treatment of stainless steel greatly improve the corrosion resistance of stainless steel stents y a biological environment, such improvement allows them to commercially compete against other materials like Cr-Co alloys. P { margin-bottom: 0.21cm; }Cardiovascular stents are made of metal alloys and they are in contact with a corrosive biological environment. The corrosion may promote loss of material, subsequent fracture for the implant and the release of metallic ions that may induce platelet adhesion, hypersensitivity reactions and recurrent restenosis. Several coatings and metal alloys have been developed to improve this situation. Methodology: The corrosion resistance of commercial stents was evaluated using potentiometry technique. 316L stainless steel (naked, gold coated, graphite coated and with a surface treatment developed in our lab) and of Cr-Co alloy were tested. The resting potential as a function of time under open circuit and the corresponding polarimetric curve were determined. Micrographs were taken to follow the process. Results: The obtained curves, show that the anodic current density of the gold and graphite coated and surface treated stents are much lower than the anodic current density of naked stents. The Cr-Co stents, also presented a good behaviour, with low corrosion rates and a clear tendency to intergranular corrosion. The naked stainless steel showed the worse behaviour with pitting and mass loss. Conclusion: the coating and the surface treatment of stainless steel greatly improve the corrosion resistance of stainless steel stents y a biological environment, such improvement allows them to commercially compete against other materials like Cr-Co alloys.