Polymers Used in Drug-Eluting Stents

1 Polyethylene-co-vinyl Acetate (PEVA) and Poly n-butyl Methacrylate (PBMA) 

Cypher is a first-generation DES that releases the immxmosuppressive agent siroli-mus (brand name Rapamxme) which is bound to polymers embedded in this stent. The Cypher system has a stainless steel base which is cut into a sinusoid shape and is coated with a blend of two polymers. The blended polymers are polyethylene-co-vinyl acetate (PEVA) and poly n-butyl methacrylate (PBMA). A combination of the two polymers mixed with sirolimus (67%/33%) makes up the basecoat formulation. Another coat of 

First-in-man clinical trials with the Cypher stent system were performed at the Institute Dante Pazzanese de Cardiologia in the year 2000, comparing a moderate-release cypher stent with a slow-release one in 15 human patients. At the time stent-technology had been an emerging field and this clinical trial helped establish the therapeutic benefits of DBS use by demonstrating slowed neointimal growth in stented patients [1]. 

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