Biocompatibility of a novel zinc stent with a closed-cell-design
Issue title: Selected Presentations held at the 34th Conference of the German Society for Clinical Microcirculation and Hemorheology, Regensburg, Germany, 27–28 November, 2015
Affiliations: [a] Center for Medical Basic Research, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany | [b] OPTIMED Medizinische Instrumente GmbH, Ettlingen, Germany | [c] Limedion GmbH, Mannheim, Germany | [d] Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstrasse, Teltow, Germany | [e] CREAMEDIX GmbH, Weingarten, Germany
Correspondence:
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Corresponding author: Bernhard Hiebl, Martin-Luther-Universität Halle-Wittenberg, Center for Medical Basic Research, Magdeburger Str. 18, D-06112 Halle. Tel.: +49 345 557 1793; Fax: +49 345 557 1436; E-mail: bernhard.hiebl@medizin.uni-halle.de
Abstract: Biomaterials made of zinc have been widely described to be antioxidative, hypothrombogenic, antiinflammatory and antiproliferative. Additionally in vivo zinc is toxic only in high concentrations and can completely be metabolized in vivo. Due to these properties zinc based vascular stents might be able to reduce the rate of restenosis in comparison to bare metal stents and zinc stents might be also able to limit the foreign body reaction. In the presented study we tested the biocompatibility and degradability of a stent made of zinc and characterized by a closed-cell-design to achieve high opening force and to increase stent stiffness. After 100 days of enzymatic and hydrolytic degradation in 15 ml blood serum (fetal calf serum) a significant loss of weight (1.72 wt% ) was measured. Zinc was compared to other metals in terms of degradation rates. After six weeks of incubation in physiologic sodium chloride solution zinc showed the slowest degradation time, 6 times less than stainless steel and 4 times less than magnesium. In the tests for cytotoxic effects the degraded zinc stent caused no changes in the LDH-release and cell membrane integrity (3T3 cells, mouse fibroblasts) respectively, in the cell activity/proliferation (MTS assay) and in the morphological characteristics of the cells and cell layers in comparison to the control material (polystyrene). Based on these results the tested zinc stent proved to be non-cytotoxic and to be characterized by degradation characteristics which might be advantageous in comparison to magnesium and stainless steel.
