NMP 2008

image1	Jinping Dong
	ADVISOR: Greg Haugstad Characterization Facility University of Minnesota

Characterizing Real-Time Drug Release from Engineered Biomedical Coatings

Jinping Dong, Chris Frethem, Greg Haugstad – Characterization Facility, University of Minnesota
Bob Hoerr, John Foley, Mike Matuszewski – Nanocopoeia, Inc
Judit Puskas – Department of Polymer Science, University of Akron

The ElectroNanospray™ process (Nanocopoeia, Inc) is used to generate nanoscale drug-polymer composite coatings on medical devices such as coronary stents in a single-stage process. Drug release from such coatings is a highly complex and poorly understood process. The traditional approach of measuring percent release over time provides researchers with only a grainy snapshot of the process and is not very informative for directing the engineering of new coatings to actively control the temporal release of drugs from medical devices. The purpose of this study was to take a comprehensive approachto examine drug sequestration, mobility and release from a polymer immersed in PBS to better understand how to engineer coatings to tailor release profiles to A model drug delivery system consisting of a polymer matrix (arborescent polyisobutylene-polystyrene, or arbIBS) and either dexamethasone or sirolimus was studied by various characterization techniques. Modification of ElectroNanospray process parameters resulted in surface coatings with rich morphologies that are revealed by SEM. Atomic Force Microscopy (AFM) and Confocal Raman Microscopy were employed to monitor the drug release process in situ, through which the mechanism of the drug-eluting process may be proposed.