title: Probing the 3D structure of cornea-like collagen liquid crystals with polarization-resolved SHG microscopy.
abstract: This work aims at characterizing the three-dimensional organization of liquid crystals composed of collagen, in order to determine the physico-chemical conditions leading to highly organized structures found in biological tissues such as cornea. To that end, we use second-harmonic generation (SHG) microscopy, since aligned collagen structures have been shown to exhibit intrinsic SHG signals. We combine polarization-resolved SHG experiments (P-SHG) with the theoretical derivation of the SHG signal of collagen molecules tilted with respect to the focal plane. Our P-SHG images exhibit striated patterns with variable contrast, as expected from our analytical and numerical calculations for plywood-like nematic structures similar to the ones found in the cornea. This study demonstrates the benefits of P-SHG microscopy for in situ characterization of highly organized biopolymers at micrometer scale, and the unique sensitivity of this nonlinear optical technique to the orientation of collagen molecules.
authors.forename: Claire
authors.initials: C
authors.lastname: Teulon
authors.forename: Aurélien
authors.initials: A
authors.lastname: Tidu
authors.forename: François
authors.initials: F
authors.lastname: Portier
authors.forename: Gervaise
authors.initials: G
authors.lastname: Mosser
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Schanne-Klein