title: Effect of anisotropy and drying of costal cartilage on its optical transmittance in laser reshaping of implants with 1, 2, and 3 mm in thickness.
abstract: Laser reshaping of cartilage is a prospective technique which can be applied for manufacturing the natural implants for otolaryngology and reconstructive surgery. Optical properties and optimal laser settings for laser reshaping of costal cartilage depend on its thickness, water content, and structural anisotropy of the tissue, in particular, the distinct orientation of collagen packing. The aim of the work is to study the effect of different collagen orientation, thickness, and drying of costal cartilage on its interaction with laser radiation.
  
  
  
  Costal cartilage was cut along and crosswise the distinct collagen orientation. The dried and normal cartilage was used for the comparative analysis. The collagen package was studied using atomic force microscopy. The dried tissue was analyzed with thermogravimetry-differential scanning calorimetry (TG-DSC) analysis to reveal the residual water content. The optical transmittance was measured for two wavelengths λ: 1,560 and 532 nm. The reshaping of cartilage of 1-3 mm in thickness was performed with infrared laser with λ = 1560 nm while, the radiation with λ = 532 nm was used to determine the location of the IR beam.
  
  
  
  The transmittance of 532 nm radiation does not depend on collagen orientation and tissue drying. The IR radiation transmits better along the distinct collagen direction in dried cartilage while in normal cartilage the intensity of transmitted IR radiation increases intermittently passing crosswise and does not change dramatically with time along the collagen orientation.
  
  
  
  The effect of structural anisotropy of costal cartilage reveals itself in the increasing scattering of IR radiation with λ = 1,560 nm passing crosswise the collagen orientation when tissue water content is decreased. The radiation with λ = 1,560 nm is effective to perform the reshaping for cartilage of 1-3 mm in thickness; however, for 3 mm, the residual mechanical stress should be taken into account. Lasers Surg. Med. 48:887-892, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, 603950, Russia. yuliasoshnikova@gmail.com.|Institute of Photonic Technologies, Federal Scientific Research Centre "Crystallography and Photonics" of the Russian Academy of Sciences, Troitsk, Moscow, 142190, Russia. yuliasoshnikova@gmail.com.|Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, 119992, Russia. yuliasoshnikova@gmail.com.
authors.forename: Yulia M
authors.initials: YM
authors.lastname: Soshnikova
authors.affiliation: Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, 119992, Russia.
authors.forename: Mariya M
authors.initials: MM
authors.lastname: Keselman
authors.affiliation: Institute of Photonic Technologies, Federal Scientific Research Centre "Crystallography and Photonics" of the Russian Academy of Sciences, Troitsk, Moscow, 142190, Russia.
authors.forename: Olga I
authors.initials: OI
authors.lastname: Baum
authors.affiliation: Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, 119992, Russia.
authors.forename: Elvira V
authors.initials: EV
authors.lastname: Shults
authors.affiliation: Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, 119992, Russia.
authors.forename: Mariya V
authors.initials: MV
authors.lastname: Obrezkova
authors.affiliation: Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, 119992, Russia.
authors.forename: Valery V
authors.initials: VV
authors.lastname: Lunin
authors.affiliation: Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, 603950, Russia.|Institute of Photonic Technologies, Federal Scientific Research Centre "Crystallography and Photonics" of the Russian Academy of Sciences, Troitsk, Moscow, 142190, Russia.
authors.forename: Emil N
authors.initials: EN
authors.lastname: Sobol
mesh_terms: D000818:Animals; D016880:Anisotropy; D001696:Biomechanical Phenomena; D066186:Costal Cartilage / Q000033:anatomy & histology / Q000737:chemistry / Q000601:surgery*; D016591:Histocytological Preparation Techniques; D007259:Infrared Rays; D007834:Lasers; D055620:Optical Phenomena; D013552:Swine
keywords: costal cartilage; implants; laser reshaping; light scattering