Abstract 17962: Novel Duplex Steel Stent Enables Nanoparticle Mediated Cell Capture and Demonstrates Endothelialization at Three Days
Introduction: The feasibility of using super-paramagnetic iron oxide nanoparticle (SPION) labeled endothelial outgrowth cells (EOC) to coat the surface of prototype magnetic stents has been shown previously. Rapid endothelialization has the potential to reduce stent thrombosis and antiplatelet agent mediated bleeding risk. We report the development of a novel bare metal stent (BMS) engineered from a magnetizable duplex stainless steel (2205). Pig coronary arteries were stented with the magnetized BMS, followed by intracoronary delivery of labeled EOCs. Arteries were harvested after 3 days to verify the capture of EOCs and to validate the efficacy of endothelialization.
Methods: EOCs cultured from autologous pig blood were labeled with biodegradable 120 nm PLGA/magnetite SPIONs and a fluorescent cell surface marker (DiI). Identical 3.0x15 mm stents were fabricated from magnetizable 2205 and non-magnetizable 316L stainless steels. Magnetized and control stents were placed in the right coronary artery (RCA) of 6 pigs. Two permanent magnets were placed external to the chest to induce additional magnetization in the 2205 stents. EOCs (4-5x106) were delivered in the RCA over 4 min via a proximally inflated over the wire balloon. External magnets were removed at 2 hr. Eleven 2205 and five 316L stents were studied after 3 days. Fluorescent microscopy and SEM were used to assess cell capture and endothelialization. All strut coverage was measured for quantification and the quality of covering tissue was not taken into consideration.
Results: Red fluorescence adjacent 2205 stents confirmed EOC retention (Fig 1a). SEM showed patchy coverage of 316L stents (b). Magnetic 2205 stents showed extensive endothelialization (c). 316L coverage: 63.3 +/- 8.1%, 2205 coverage: 97.8 +/- 1.1%, p=0.01.
Conclusions: These data demonstrate for the first time that magnetically localized autologous endothelial cells are capable of promoting healing of a stented porcine coronary artery.
- © 2013 by American Heart Association, Inc.