Development of a novel biocompatible polymer system for extended drug release in a next-generation drug-eluting stent.
Drug-eluting stents have proven superior to bare metal stents with lower restenosis rates. Local delivery of drugs from these stents is achieved in most cases with the help of biostable polymer coatings. However, since the polymer coating remains in the body well after all the drug is released, patients can potentially develop hypersensitivity to these polymers--leading to complications such as late-stent thrombosis. It is therefore important that the polymers are designed to be biocompatible and well tolerated by the body. The polymer coatings are also expected to be robust and provide good control over elution of the desired drug. This paper describes the development of a unique, proprietary polymer blend system, specially designed to meet these requirements. Mutually compatible, free-radical-initiated elastomeric polymers were designed to provide a robust coating and offer a steady, sustained release of the highly hydrophobic drug zotarolimus over an extended period. The polymer blend system is also well tolerated by the hydrophilic environment in vivo, as demonstrated through porcine studies.
Udipi
Kishore
K
Medtronic CardioVascular, 3576 Unocal Pl., Santa Rosa, California 95403, USA. kishore.udipi@medtronic.com
Chen
Mingfei
M
Cheng
Peiwen
P
Jiang
Kevin
K
Judd
Diane
D
Caceres
Alejandra
A
Melder
Robert J
RJ
Wilcox
Josiah N
JN
D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000737:chemistry; D016503:Drug Delivery Systems; D054855:Drug-Eluting Stents; D008422:Materials Testing / Q000379:methods*; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D020123:Sirolimus / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D013552:Swine; D044366:Transition Temperature
D001672:Biocompatible Materials; D011108:Polymers; C489443:zotarolimus; D020123:Sirolimus