Optical imaging predicts mechanical properties during decellularization of cardiac tissue

Nick Merna, Claire Robertson, Anh La, Steven George

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Decellularization of xenogeneic hearts offers an acellular, naturally occurring, 3D scaffold that may aid in the development of an engineered human heart tissue. However, decellularization impacts the structural and mechanical properties of the extracellular matrix (ECM), which can strongly influence a cell response during recellularization. We hypothesized that multiphoton microscopy (MPM), combined with image correlation spectroscopy (ICS), could be used to characterize the structural and mechanical properties of the decellularized cardiac matrix in a noninvasive and nondestructive fashion. Whole porcine hearts were decellularized for 7 days by four different solutions of Trypsin and/or Triton. The compressive modulus of the cardiac ECM decreased to <20% of that of the native tissue in three of the four conditions (range 2-8 kPa); the modulus increased by ∼150% (range 125-150 kPa) in tissues treated with Triton only. The collagen and elastin content decreased steadily over time for all four decellularization conditions. The ICS amplitude of second harmonic generation (SHG, ASHG) collagen images increased in three of the four decellularization conditions characterized by a decrease in fiber density; the ICS amplitude was approximately constant in tissues treated with Triton only. The ICS ratio (RSHG, skew) of collagen images increased significantly in the two conditions characterized by a loss of collagen crimping or undulations. The ICS ratio of two-photon fluorescence (TPF, RTPF) elastin images decreased in three of the four conditions, but increased significantly in Triton-only treated tissue characterized by retention of densely packed elastin fibers. There were strong linear relationships between both the log of ASHG (R 2=0.86) and RTPF (R2=0.92) with the compressive modulus. Using these variables, a linear model predicts the compressive modulus: E=73.9×Log(ASHG)+70.1×RTPF - 131 (R2=0.94). This suggests that the collagen content and elastin alignment determine the mechanical properties of the ECM. We conclude that MPM and ICS analysis is a noninvasive, nondestructive method to predict the mechanical properties of the decellularized cardiac ECM.

Original languageEnglish (US)
Pages (from-to)802-809
Number of pages8
JournalTissue Engineering - Part C: Methods
Volume19
Issue number10
DOIs
StatePublished - Oct 1 2013

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Optical Imaging
Elastin
Spectrum Analysis
Collagen
Spectroscopy
Tissue
Imaging techniques
Mechanical properties
Extracellular Matrix
Structural properties
Microscopy
Microscopic examination
Fibers
Human Development
Harmonic generation
Photons
Scaffolds
Trypsin
Linear Models
Swine

ASJC Scopus subject areas

  • Bioengineering
  • Medicine (miscellaneous)
  • Biomedical Engineering

Cite this

Optical imaging predicts mechanical properties during decellularization of cardiac tissue. / Merna, Nick; Robertson, Claire; La, Anh; George, Steven.

In: Tissue Engineering - Part C: Methods, Vol. 19, No. 10, 01.10.2013, p. 802-809.

Research output: Contribution to journalArticle

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