Method to determine particle release during long-term loading for assessment of coating durability of cardiovascular stents

Autor: Wolfram Schmidt, Christoph Brandt-Wunderlich, Anja Kurzhals, Klaus-Peter Schmitz, Niels Grabow
Rok vydání: 2021
Předmět:
Zdroj: Current Directions in Biomedical Engineering, Vol 7, Iss 2, Pp 704-707 (2021)
ISSN: 2364-5504
DOI: 10.1515/cdbme-2021-2179
Popis: Many catheters and vascular implants are coated to increase biocompatibility or to reduce friction during catheter based implantation. Several regulations require assessment of coating durability over the implant’s life time. An in vitro method for stent testing is presented to measure released particulate matter at defined inspection intervals. The method was validated using polystyrene microspheres with a size of 10, 25 and 50 μm to check for particle recovery (n=6). Two cleaning steps followed. Particle counting was performed by light obscuration method. The recovery rate was 103±5% (10μm), 94±4% (25 μm) and 78±12% (50 μm), respectively, meeting the requirements of FDA guidance documents (i.e. FDA 1545). Less than 3% of the particles were found in the cleaning solutions. The method using a fixed volume during stent loading can be adapted to all durability testers where tubes are used to fix the stents (radial pulsatile, bending, axial compression, torsion).
Databáze: OpenAIRE