title: Real-time confocal Raman imaging of a drug delivery system on cardiac leads.
abstract: Drug delivery systems incorporated onto the end of cardiac leads are used to reduce inflammation and fibrosis at the lead-tissue interface and enable optimal lead performance. In this research, confocal Raman microscopy was used to capture chemical images of the drug delivery system on pacemaker leads in different elution media in real-time. Raman images in ambient air showed that drug was dispersed in the polymer matrix as discrete particles with size ranging from 1 to 3 microm. Upon immersion into an aggressive elution medium, drug near the surface dissolved immediately and solvent started to penetrate into the polymer matrix through channels from which drug was eluted. The drug depletion depth was a function of time, which was consistent with the drug release profiles obtained by HPLC. Comparing the drug elution in aggressive solvent and biorelevant solvent, a mechanism of drug release is proposed.
authors: Characterization Facility, Institute of Technology, University of Minnesota, 12 Shepherd Labs, 100 Union St SE, Minneapolis, MN 55455, USA. dongx033@umn.edu
authors: Jinping
authors: J
authors: Dong
authors: Jeannette
authors: J
authors: Polkinghorne
authors: Ronald
authors: R
authors: Heil
authors: Ruth
authors: R
authors: Kemp
mesh_terms: D003199:Computer Systems; D004058:Diffusion; D004353:Drug Evaluation, Preclinical / Q000379:methods; D004343:Drug Implants / Q000032:analysis / Q000737:chemistry*; D004567:Electrodes, Implanted; D018613:Microscopy, Confocal / Q000379:methods*; D010138:Pacemaker, Artificial; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D004343:Drug Implants