Abstract 12954: A Novel-Particle Image Velocimetry (PIV) Assay to Measure the Maturity and Functional Cardiomyocytes Contractility
Introduction: The most important functional property of cardiomyocytes (CMCs) from a therapeutic standpoint is the ability to produce contractile force. Current methods of assessing the same, such as patch clamping and confocal calcium imaging, are labor-intensive, invasive or require fluo-dye in culture medium, which can affect the cells’ contractility. No optimal method is currently available to assess CMC functionality.
Hypothesis: We hypothesized that a novel particle image velocimetry (PIV) method would provide accurate assessment of CMC contractility and maturity.
Methods: We generated induced pluripotent stem cells (iPSCs) from adult human cells using a highly efficient viral-free transfection of DNA and mRNA combination. iPSCs were further differentiated into functional CMCs with defined culture conditions.
Results: To analyze the contractility of iPSC-derived CMCs (iCMCs), we recorded the same areas of culture plate at various time-points using high frame-rate video microscopy (Fig. A, n=11). A novel image analysis technique provided beat patterns time series data of cell displacement, measured relative to a resting reference state (Fig. B, C). As beat patterns of recordings in video microscopic images revealed, the contractility of early CMC nodes was asynchronous in space and irregular in time (Fig. D1-D2, three beating fields are marked as red, green and blue). During subsequent days after the onset of beating, however, the spatially distinct contractile centers became synchronous even as their frequency remained unstable (Fig. D3-D6). The transmission electron microscopic images confirmed a well-developed pattern of sarcomeres in late-stage (day 30) CMCs.
Conclusions: This PIV image analysis is a novel method that enables assessment of CMC contractility multiple times, if necessary, without jeopardizing the biology of cells. This method may also prove beneficial for drug screening and detection of cardiotoxicity in iPSC-derived CMCs.
Author Disclosures: J. Rajasingh: Research Grant; Modest; 10SDG2630181. S. Rajasingh: None. A. Czirok: None. S. Samanta: None. D.G. Isai: None. E. Kosa: None. B. Dawn: Research Grant; Modest; R01HL117730.
- © 2015 by American Heart Association, Inc.