title: Real-time in situ monitoring of poly(lactide-co-glycolide) coating of coronary stents using electrochemical impedance spectroscopy.
abstract: Monitoring erosion progress of biodegradable drug carrying polymer coated on coronary drug eluting stents (DES) is largely hindered because of the small amount of coating material as well as the irregular profile of coating, both of which make the monitoring using traditional methods highly challenging. In our study, electrochemical impedance spectroscopy (EIS), a widely used method in the study of metal corrosion, was used to address the challenges traditional methods face. In vitro, remained mass and molecular weight drop data of film-like poly(lactide-co-glycolide) (PLGA) samples due to degradation were monitored using traditional mass loss measurement and size exclusion chromatography (SEC) methods. The obtained data were compared to the changes of capacitance and impedance measured by EIS from PLGA-coated stainless slices with an equivalent electrical circuit model. The results showed that the changes of the resistance and capacitance obtained by EIS, which indicates transformations of PLGA coating, can be correlated to the degradation measured by traditional methods, such as SEC. Furthermore, EIS method was applied to monitor and evaluate the erosion progress of a real stent with PLGA coating. Our results suggested that EIS method can accurately monitor real-time erosion process of thin polymer coatings on DES in situ.
authors: College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210093, People's Republic of China.
authors: Qi
authors: Q
authors: Zhong
authors: Qunlong
authors: Q
authors: Mao
authors: Jin
authors: J
authors: Yan
authors: Wenming
authors: W
authors: Liu
authors: Tao
authors: T
authors: Zhang
authors: Jianguo
authors: J
authors: Liu
mesh_terms: D020341:Absorbable Implants; D002850:Chromatography, Gel; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003199:Computer Systems; D003343:Corrosion; D058266:Dielectric Spectroscopy; D054855:Drug-Eluting Stents; D025802:Electric Capacitance; D017097:Electric Impedance; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D008970:Molecular Weight; D009204:Myocardial Revascularization / Q000295:instrumentation*; D011098:Polyglactin 910 / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D011098:Polyglactin 910
keywords: degradation; drug eluting stents; electrochemical impedance spectroscopy; poly(lactide-co-glycolide)