Poly(ethylene carbonate): A thermoelastic and biodegradable biomaterial for drug eluting stent coatings?

Titelangaben

Unger, F. ; Westedt, Ullrich ; Hanefeld, Phillip ; Wombacher, Ralf ; Zimmermann, S. ; Greiner, Andreas ; Ausborn, M. ; Kissel, Thomas:
Poly(ethylene carbonate): A thermoelastic and biodegradable biomaterial for drug eluting stent coatings?
In: Journal of Controlled Release. Bd. 117 (2007) Heft 3 . - S. 312-321.
ISSN 1873-4995
DOI: https://doi.org/10.1016/j.jconrel.2006.11.003

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Abstract

A first feasibility study exploring the utility of poly(ethylene carbonate) (PEC) as coating material for drug eluting stents under in vitro conditions is reported. PEC (Mw 242 kDa, Mw/Mn=1.90) was found to be an amorphous polymer with thermoelastic properties. Tensile testing revealed a stress to strain failure of more than 600%. These properties are thought to be advantageous for expanding coated stents. In vitro cytotoxicity tests showed excellent cytocompatibility of PEC. Based on these findings, a new stenting concept was suggested, pre-coating a bare-metal stent with PPX-N as non-biodegradable basis and applying a secondary PEC coating using an airbrush method. After manual expansion, no delamination or destruction of the coating could be observed using scanning electron microscopy. The surface degradation-controlled release mechanism of PEC may provide the basis for ``on demand'' drug eluting stent coatings, releasing an incorporated drug predominantly at an inflamed implantation site upon direct contact with superoxide-releasing macrophages. As a release model, metal plates of a defined size and area were coated under the same conditions as the stents with PEC containing radiolabelled paclitaxel. An alkaline KO2- solution served as a superoxide source. Within 12 h, 100% of the incorporated paclitaxel was released, while only 20% of the drug was released in non-superoxide releasing control buffer within 3 weeks. (c) 2006 Elsevier B.V. All rights reserved.