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Updated: Jan 14, 2026
Isolation of Mouse Interstitial Valve Cells to Study the Calcification of the Aortic Valve In Vitro
Published on: May 10, 2021
In Vitro Calcification of Bioprosthetic Heart Valves: Method Validation by Comparative Heart Valve Calcification
Nicole Kiesendahl1,2, Christoph Schmitz1, Lars Peters3
1Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Medical Faculty RWTH Aachen University, Aachen, Germany.
Background:
A major reason for the failure of bioprosthetic heart valves is calcification. Various pretreatment methods are developed to reduce the calcification behavior. The effectiveness of these methods has so far been investigated in expensive and time-consuming large animal studies. To provide a cost-effective, animal- and possibly also time-saving method, we developed an accelerated dynamic in vitro calcification test method.
Methods:
We validated this method using a comparative study of two differently pretreated groups of porcine heart valve bioprostheses. Each group contained N = 4 identical aortic bioprostheses. Calcification onsets, progression, and extent were detected by high-speed video (HSV) documentation and microscopy. Structural identification of the deposits was carried out by X-ray powder diffraction (XRD). Semi-destructive quantification of the calcifications was done by μ-CT as well as destructive chemical quantification via colorimetry and complexometry. The histomorphologic localization of the calcifications was examined by von Kossa staining.
Results:
Structural analysis of the deposits indicated "biological apatite" for both test groups. Histological examination revealed localization of the calcifications in the spongiosa zone of the cusps. Quantification of the calcifications showed a distinctly stronger calcification tendency of the No-T6 compared to the anti-calcifying pretreated T6 bioprostheses.
Conclusions:
We developed and validated a novel and unique test method for in vitro calcification assessment. The quantitative calcification tendencies of the two test groups are comparable with the results of an in vivo study in sheep. The structural findings are in line with published in vivo observations. The histomorphological localization appears as known for porcine prostheses.
