gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie
72. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie, 94. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie und 49. Tagung des Berufsverbandes der Fachärzte für Orthopädie und Unfallchirurgie

22. - 25.10.2008, Berlin

Capacity of TGF-β1-stimulated local chondrocytes to regenerate a cartilage defect filled with nanocellulose matrix

Meeting Abstract

  • D. Pretzel - Friedrich-Schiller University Jena, Experimental Rheumatology Unit, Department of Orthopedics, Eisenberg, Germany
  • U. Kramer - POLYMET Jena e.V., Jena, Germany
  • D. Schumann - POLYMET Jena e.V., Jena, Germany
  • D. Klemm - POLYMET Jena e.V., Jena, Germany
  • M. Sittinger - Charité, Universitätsmedizin, Tissue engineering laboratory, Berlin, Germany
  • J. Ringe - Charité, Universitätsmedizin, Tissue engineering laboratory, Berlin, Germany
  • R.W. Kinne - Friedrich-Schiller University Jena, Experimental Rheumatology Unit, Department of Orthopedics, Eisenberg, Germany

Deutscher Kongress für Orthopädie und Unfallchirurgie. 72. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie, 94. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie, 49. Tagung des Berufsverbandes der Fachärzte für Orthopädie. Berlin, 22.-25.10.2008. Düsseldorf: German Medical Science GMS Publishing House; 2008. DocPO12-1125

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/dkou2008/08dkou643.shtml

Veröffentlicht: 16. Oktober 2008

© 2008 Pretzel et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Introduction: Local cartilage defects do not show spontaneous regeneration or filling of the defect without additional measures. There are well-established treatment methods like cartilage drilling/microfracturing or autologous chondrocyte transplantation (ACT). Due to the problems of the conventional treatment strategies (cell expansion, additional damage of non-affected regions, and quality of the regenerative tissue), an alternative approach was developed using the capacity of resident cartilage chondrocytes in combination with chondroinductive TGF-β1 and a bacterially synthesized nanocellulose (BC) as a biocompatible and non-resorbable matrix.

Objective: In the present study, the capacity of TGF-β1-stimulated local chondrocytes to regenerate a cartilage defect filled with the nanocellulose matrix was assessed.

Methods: In a newly developed in vitro model a localized cartilage defect (2 mm diameter) was created in bovine cartilage discs (7 mm diameter ) using a biopsy punch. Subsequently, the defect was filled with the never dried matrix consisting of non-resorbable nanocellulose, which acts as a scaffold for the ingrowth of cells. The construct was cultured in vitro for 2 and 4 weeks respectively, with the addition of TGF-β1 (0, 10, 50, 100 ng/ml). Subsequently, frozen sections (8 µm) were histologically processed. For general morphology, the samples were subjected to staining with Hematoxylin/Eosin (HE). Detection of proteoglycans was performed using Safranin O/Fast green (SO) staining and the aggrecan content was analysed by immunohistological staining with specific antibodies for intact aggrecan.

Results: After 2 and 4 weeks, the cartilage matrix surrounding the defect remained fully intact with strong SO positivity and vital chondrocytes. However empty chondrocyte lacunas were observed at the edges of the cartilage explant. There was good bonding between the contact zone of the cartilage defect and the BC matrix due to its strong swelling capacity. Vital chondrocytes migrated from the cartilage matrix onto the edges of the BC-matrix and showed signs of adherence. The main finding was that after 4 weeks of culture TGF-β1-stimulated samples (all concentrations) showed positive staining with SO within the BC-matrix, indicating proteoglycan deposition. This was confirmed by immunohistological staining, showing a comparably strong positive reaction for aggrecan in the NC-matrix and the surrounding cartilage.

Conclusion: In the present cartilage regeneration model, an elevated proteoglycan (aggrecan)-content within the BC insert was observed after 4 weeks of stimulation with the chondrogenic factor TGF-β1. This suggests that endogenous chondrocytes may have the capacity to regenerate an initially cell-free defect filled with BC.