Biomedical Microdevices

, Volume 15, Issue 1, pp 171–181

Sacrificial layer technique for axial force post assay of immature cardiomyocytes

  • Rebecca E. Taylor
  • Keekyoung Kim
  • Ning Sun
  • Sung-Jin Park
  • Joo Yong Sim
  • Giovanni Fajardo
  • Daniel Bernstein
  • Joseph C. Wu
  • Beth L. Pruitt
Article

DOI: 10.1007/s10544-012-9710-3

Cite this article as:
Taylor, R.E., Kim, K., Sun, N. et al. Biomed Microdevices (2013) 15: 171. doi:10.1007/s10544-012-9710-3

Abstract

Immature primary and stem cell-derived cardiomyocytes provide useful models for fundamental studies of heart development and cardiac disease, and offer potential for patient specific drug testing and differentiation protocols aimed at cardiac grafts. To assess their potential for augmenting heart function, and to gain insight into cardiac growth and disease, tissue engineers must quantify the contractile forces of these single cells. Currently, axial contractile forces of isolated adult heart cells can only be measured by two-point methods such as carbon fiber techniques, which cannot be applied to neonatal and stem cell-derived heart cells because they are more difficult to handle and lack a persistent shape. Here we present a novel axial technique for measuring the contractile forces of isolated immature cardiomyocytes. We overcome cell manipulation and patterning challenges by using a thermoresponsive sacrificial support layer in conjunction with arrays of widely separated elastomeric microposts. Our approach has the potential to be high-throughput, is functionally analogous to current gold-standard axial force assays for adult heart cells, and prescribes elongated cell shapes without protein patterning. Finally, we calibrate these force posts with piezoresistive cantilevers to dramatically reduce measurement error typical for soft polymer-based force assays. We report quantitative measurements of peak contractile forces up to 146 nN with post stiffness standard error (26 nN) far better than that based on geometry and stiffness estimates alone. The addition of sacrificial layers to future 2D and 3D cell culture platforms will enable improved cell placement and the complex suspension of cells across 3D constructs.

Keywords

Force posts Thermoresponsive Sacrificial layer Cardiomyocytes PDMS Stem cells 

Supplementary material

ESM 1

Beating primary neonatal rat cardiomyocyte on force sensor (MPG 1,062 kb)

ESM 2

Beating hESC-derived cardiomyocyte on force sensor (MPG 460 kb)

Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  • Rebecca E. Taylor
    • 1
  • Keekyoung Kim
    • 1
    • 2
  • Ning Sun
    • 4
  • Sung-Jin Park
    • 3
  • Joo Yong Sim
    • 1
  • Giovanni Fajardo
    • 2
  • Daniel Bernstein
    • 2
  • Joseph C. Wu
    • 4
  • Beth L. Pruitt
    • 1
  1. 1.Department of Mechanical Engineering and Stanford Cardiovascular InstituteStanford UniversityStanfordUSA
  2. 2.Stanford Cardiovascular Institute and Department of Pediatrics (Cardiology)Stanford University School of MedicineStanfordUSA
  3. 3.Department of Mechanical EngineeringStanford UniversityStanfordUSA
  4. 4.Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Stanford Institute of Stem Cell Biology & Regenerative MedicineStanford University School of MedicineStanfordUSA
  5. 5.Disease Biophysics Group, School of Engineering and Applied SciencesHarvard UniversityCambridgeUSA
  6. 6.Department of Agricultural and Biological Engineering and Department of Mechanical and Nuclear EngineeringPennsylvania State UniversityUniversity ParkUSA

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