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Quantitative characterization of physiological degradation processes in situ by means of a bioreactor coupled flow chamber using timelapse SRµCT

Wednesday (28.09.2016)
11:30 - 11:45
Part of:

The use of degradable magnesium based implants is becoming clinically relevant, especially for the use of degradable stents. Still there is a lack of analyzing techniques to characterize the in vitro degradation behavior of implant prototypes. In order to characterize the in vitro degradation behavior of implant prototypes we have developed and manufactured a fully sterilizable flow cell system from polyether etherketone (PEEK) to study bio- degradable magnesium based implants under physiological conditions by time-lapse SRµCT. The use of physiological conditions was chosen to get a better approach to the in vivo situation, as it could be shown by many studies, that these conditions change on the one hand the degradation rate and on the other hand also the formed degradation products. Physiological conditions (temperature, oxygen and CO2 levels) for the in situ environment are controlled and monitored by a closed bioreactor system to grant sterility of the setup and follow chemical components indirectly. A flow cell was designed and manufactured from polyether etherketone (PEEK), which was chosen because of the good mechanical properties, high thermal and chemical resistance and radiographic translucency. Sterilization of the system including the sample was reached by a transient flush with 70 % ethanol and subsequent replacement by physiological medium (Modified Eagle Medium alpha). As Proof of principle it could be shown that the system remained sterile during a beamtime / period of 5 days and that the continuous SRµCT imaging was feasible. The entire system is integrated as flexible sample environment into the micro tomography endstation of the Imaging Beamline P05 at the storagering PETRA III (DESY). The system has been successfully tested in a 5 d magnesium degradation experiment.

Dr. Jörg U. Hammel
Helmholtz-Zentrum Geesthacht
Additional Authors:
  • Dr. Frank Feyerabend
    Helmholtz-Zentrum Geesthacht
  • Thomas Dose
    Helmholtz-Zentrum Geesthacht
  • Alexander Hipp
    Helmholtz-Zentrum Geesthacht
  • Dr. Fabian Wilde
    Helmholtz-Zentrum Geesthacht
  • Dr. Felix Beckmann
    Helmholtz-Zentrum Geesthacht