gms | German Medical Science

German Congress of Orthopedic and Trauma Surgery (DKOU 2017)

24.10. - 27.10.2017, Berlin

Extracellular matrix development and cell invasion at the defect site in an in vitro model for cartilage integration

Meeting Abstract

  • presenting/speaker Oliver Berberich - University Hospital Würzburg, Würzburg, Germany
  • Felix Kiepe - University Hospital Würzburg, Würzburg, Germany
  • Alexander Kossmann - University Hospital Würzburg, Würzburg, Germany
  • Thomas Böck - University Hospital Würzburg, Würzburg, Germany
  • Rainer Meffert - University Hospital Würzburg, Würzburg, Germany
  • Stefanie Hölscher-Doht - University Hospital Würzburg, Würzburg, Germany
  • Wiltrud Richter - University Hospital Heidelberg, Heidelberg, Germany
  • Torsten Blunk - University Hospital Würzburg, Würzburg, Germany

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2017). Berlin, 24.-27.10.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. DocGR16-607

doi: 10.3205/17dkou513, urn:nbn:de:0183-17dkou5133

Published: October 23, 2017

© 2017 Berberich et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.


Outline

Text

Objectives: After traumatic injuries the poor lateral cartilage integration between fractured articular surfaces is a major cause of early osteoarthritis. The use of tissue adhesives that are permissive for neocartilage formation, such as fibrin hydrogels, may enhance regeneration. Improving extracellular matrix (ECM) deposition at the defect site would benefit successful long-term integration of articular cartilage. In this study a commercial fibrin glue (TissuCol®) and two formulations of long-term stable fibrin gel developed by our group were assessed. Utilizing a biomechanical in vitro model and tissue culture, the lateral integration strength, ECM synthesis, and cell migration was investigated over time.

Methods: Cartilage disc/ring composites were generated from porcine cartilage blocks harvested from the femoropatellar groove. At the defect interface, disc/ring composites were treated with either TissuCol® or two different formulations of long-term stable fibrin (25 or 50 mg/ml fibrinogen). Constructs receiving no fibrin served as control. The effects of ascorbic acid (0, 50 and 100 µg/ml) as a co-factor in collagen synthesis and of ethyl-3,4-dihydroxybenzoate (EDHB), a collagen synthesis inhibitor, were investigated. Using a biomechanical push-out device, adhesive strength was determined as measure for cartilage integration 2 hours after fibrin application and after culture for up to 3 weeks. ECM development and cell invasion at the defect site was analysed histologically and immunohistochemically.

Results and Conclusion: In contrast to control samples (without fibrin glue, no bonding), all three fibrin-treated groups possessed low immediate bonding values up to 13.5±3.9 kPa. Adhesive strength increased strongly over time to values up to 108.9±46.2 kPa (long-term stable fibrin [50 mg/ml], after 3 weeks). The biomechanical results were well reflected by cell invasion into fibrin gels and strong synthesis of cartilage-specific ECM components such as glycosaminoglycans and collagen II (no collagen I) within the gels. In fibrin-treated composites ECM deposition at the defect site was already obvious at day 3 and increased further over time. Interestingly, cell invasion was not detected before day 14 of culture. The inhibition of collagen synthesis by either omitting ascorbic acid from or adding EDHB to the culture medium strongly impaired integration.

Our study demonstrates that employing biocompatible fibrin hydrogels can lead to strongly increasing lateral cartilage integration strength over time. This observation correlated well with ECM development at the defect site, especially newly synthesized collagen proved to be crucial for integration. Nevertheless, for clinical application, new adhesive materials that lead to stronger immediate bonding and still enable subsequent ECM development appear desirable.

Acknowledgement: Funding from XXX.