Molecular imaging of drug-eluting coronary stents: method development, optimization and selected applications

A molecular imaging application was developed to characterize the drug distribution on CYPHER® and NEVO™ Drug-eluting Stents using MALDI Qq-ToF analytical methodology. The coating matrix, laser energy, laser frequency, spatial resolution (related to rastering speed) and mass spectrometer parameters were optimized to analyze drug distribution in both durable and biodegradable polymer matrices. The developed method was extended to generate data from stents explanted from porcine coronary arteries. Due to the method's intrinsic specificity, it offers a significant advantage over other techniques in that it allows low-level detection of the target molecule without biological interferences from the blood or tissue. The method is also capable of detecting drug-related degradation products both from the finished stent product and from explanted stents.