title: Cartilage labelling for mechanical testing in T-peel configuration.
abstract: OBJECTIVE
  The purpose of this study was to find a suitable method of labelling cartilage samples for the measurement of distraction distances in biomechanical testing.
  
  
  METHODS
  Samples of bovine cartilage were labelled using five different methods: hydroquinone and silver nitrate (AgNO3), potassium permanganate (KMnO4) with sodium thiosulphate (Na2S2O3), India ink, heat, and laser energy. After the labelling, we analysed the cartilage samples with regard to cytotoxity by histochemical staining with ethidiumbromide homodimer (EthD-1) and calcein AM. Furthermore, we tested cartilages labelled with India ink and heat in a T-peel test configuration to analyse possible changes in the mechanical behaviour between marked and unlabelled samples.
  
  
  RESULTS
  Only the labelling methods with Indian ink or a heated needle showed acceptable results in the cytotoxity test with regard to labelling persistence, accuracy, and the influence on consistency and viability of the chondrocytes. In the biomechanical T-peel configuration, heat-labelled samples collapsed significantly earlier than unlabelled samples.
  
  
  CONCLUSIONS
  Labelling bovine cartilage samples with Indian ink in biomechanical testing is a reliable, accurate, inexpensive, and easy-to-perform method. This labelling method influenced neither the biomechanical behaviour nor the viability of the tissue compared to untreated bovine cartilage.
authors.affiliation: Department of Orthopedics and Trauma Surgery, University Hospital Regensburg, and Biomechanics, University of Applied Science, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Pfeifer
authors.forename: Michael
authors.initials: M
authors.lastname: Müller
authors.forename: Lukas
authors.initials: L
authors.lastname: Prantl
authors.forename: Arne
authors.initials: A
authors.lastname: Berner
authors.forename: Sebastian
authors.initials: S
authors.lastname: Dendorfer
authors.forename: Carsten
authors.initials: C
authors.lastname: Englert
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002244:Carbon; D002358:Cartilage, Articular / Q000737:chemistry* / Q000187:drug effects / Q000473:pathology; D002417:Cattle; D002470:Cell Survival / Q000187:drug effects; D019902:Chondrocytes / Q000737:chemistry* / Q000187:drug effects / Q000473:pathology; D004396:Coloring Agents / Q000737:chemistry* / Q000494:pharmacology; D006358:Hot Temperature; D006873:Hydroquinones / Q000737:chemistry / Q000494:pharmacology; D007834:Lasers; D008422:Materials Testing; D011196:Potassium Permanganate / Q000737:chemistry / Q000494:pharmacology; D015203:Reproducibility of Results; D012835:Silver Nitrate / Q000737:chemistry / Q000494:pharmacology; D013194:Staining and Labeling / Q000379:methods*; D013885:Thiosulfates / Q000737:chemistry / Q000494:pharmacology
chemical_list: D004396:Coloring Agents; D006873:Hydroquinones; D013885:Thiosulfates; C028433:chinese ink; D011196:Potassium Permanganate; D002244:Carbon; D012835:Silver Nitrate; C017717:sodium thiosulfate; C031927:hydroquinone