Two-photon Microscopy and Polarimetry for Assessment of Myocardial Tissue Organization

• Main Author: Archambault-Wallenburg, Marika
• Other Authors: Vitkin, Alex
• Language: en_ca
• Published: 2010
• Subjects: Myocardial infarction; Stem cell regeneration; Non-linear optics; Polarimetry; 0760; 0752
• Online Access: http://hdl.handle.net/1807/25410

Optical methods can provide useful tissue characterization tools. For this project, two-photon microscopy and polarized light examinations (polarimetry) were used to assess the organizational state of myocardium in healthy, infarcted, and stem-cell regenerated states. Two-photon microscopy visualizes collagen through second-harmonic generation and myocytes through two-photon excitation autofluorescence, providing information on the composition and structure/organization of the tissue. Polarimetry measurements yield a value of linear retardance that can serve as an indicator of tissue anisotropy, and with a dual-projection method, information about the anisotropy axis orientation can also be extracted. Two-photon microscopy results reveal that stem-cell treated tissue retains more myocytes and structure than infarcted myocardium, while polarimetry findings suggest that the injury caused by temporary ligation of a coronary artery is less severe and more diffuse that than caused by a permanent ligation. Both these methods show potential for tissue characterization.