title: In vitro enzymatic treatment and carbon dioxide laser beam irradiation of morphologic cartilage specimens.
abstract: OBJECTIVE
  To determine the role of the main cartilage components in the internal system of interlocked stresses and to clarify the effect of laser beam irradiation on cartilage.
  
  
  METHODS
  Control and experimental series.
  
  
  METHODS
  Rabbit ear cartilage.
  
  
  METHODS
  Rabbit ear cartilage strips incubated in collagenase and hyaluronidase enzyme solutions for specific periods were examined, and the observed changes in shape, strength, and elasticity were recorded, as well as the effect of carbon dioxide laser irradiation. Laser-pretreated cartilage strips were also incubated in the enzyme solutions to determine whether the laser-provoked changes were susceptible to enzymatic action. All cartilage pieces were examined by light and electron microscopy.
  
  
  RESULTS
  Collagenase-treated cartilage strips gradually lost their interlocked stresses, while hyaluronidase-treated strips mostly maintained their shape and their physical characteristics. Hyaluronidase-incubated cartilage strips altered their shape when they were laser treated. Collagenase-treated cartilages did not modify their shape when they were laser treated. Laser-pretreated cartilage pieces lost their new form in collagenase solutions but kept their laser-evoked shape when put in hyaluronidase solutions.
  
  
  CONCLUSIONS
  The macroscopic observations combined with light and electron microscopy findings argue for the distinct role of the collagen network in morphologic cartilage shape and tensile strength preservation and provide a probable mechanism of cartilage transformation owing to carbon dioxide laser irradiation.
authors.affiliation: Department of Otolaryngology, University Hospital of Crete, Heraklion, Greece.
authors.forename: Jiannis K
authors.initials: JK
authors.lastname: Hajiioannou
authors.forename: Antonios
authors.initials: A
authors.lastname: Nikolidakis
authors.forename: Irene
authors.initials: I
authors.lastname: Naumidi
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Helidonis
authors.forename: Giannis
authors.initials: G
authors.lastname: Tzanakakis
authors.forename: George A
authors.initials: GA
authors.lastname: Velegrakis
mesh_terms: D000818:Animals; D003094:Collagen / Q000648:ultrastructure; D017364:Collagenases / Q000494:pharmacology*; D004425:Ear Cartilage / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure; D006821:Hyaluronoglucosaminidase / Q000494:pharmacology*; D066298:In Vitro Techniques; D007834:Lasers; D046529:Microscopy, Electron, Transmission; D011817:Rabbits
chemical_list: D003094:Collagen; D006821:Hyaluronoglucosaminidase; D017364:Collagenases