title: Molecular Order of Arterial Collagen Using Circular Polarization Second-Harmonic Generation Imaging.
abstract: Second-harmonic generation (SHG) originates from the interaction between upconverted fields from individual scatterers. This renders SHG microscopy highly sensitive to molecular distribution. Here, we aim to take advantage of the difference in SHG between aligned and partially aligned molecules to probe the degree of molecular order during biomechanical testing, independently of the absolute orientation of the scattering molecules. Toward this goal, we implemented a circular polarization SHG imaging approach and used it to quantify the intensity change associated with collagen fibers straightening in the arterial wall during mechanical stretching. We were able to observe the delayed alignment of collagen fibers during mechanical loading, thus demonstrating a simple method to characterize molecular distribution using intensity information alone.
authors.affiliation: Wellman Center for Photomedicine and Center for System Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Department of Biomedical Engineering, Boston University, Boston, Massachusetts.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Turcotte
authors.affiliation: Department of Mechanical Engineering, Boston University, Boston, Massachusetts.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Mattson
authors.affiliation: Wellman Center for Photomedicine and Center for System Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Juwell W
authors.initials: JW
authors.lastname: Wu
authors.affiliation: Department of Biomedical Engineering, Boston University, Boston, Massachusetts; Department of Mechanical Engineering, Boston University, Boston, Massachusetts.
authors.forename: Yanhang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Wellman Center for Photomedicine and Center for System Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts. Electronic address: lin@helix.mgh.harvard.edu.
authors.forename: Charles P
authors.initials: CP
authors.lastname: Lin
mesh_terms: D000818:Animals; D001158:Arteries / Q000648:ultrastructure; D024022:Fibrillar Collagens / Q000378:metabolism / Q000648:ultrastructure*; D006801:Humans; D013314:Stress, Mechanical
chemical_list: D024022:Fibrillar Collagens