Improved cartilage integration and interfacial strength after enzymatic treatment in a cartilage transplantation model

• Published in: Arthritis research & therapy Vol. 6; no. 5; pp. R469 - R476
• Main Authors: van de Breevaart Bravenboer, Jarno, In der Maur, Caroline D, Bos, P Koen, Feenstra, Louw, Verhaar, Jan A N, Weinans, Harrie, van Osch, Gerjo J V M
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 01-01-2004; BioMed Central
• Subjects: Animals; Articular cartilage; Care and treatment; Cartilage, Articular - chemistry; Cartilage, Articular - drug effects; Cartilage, Articular - pathology; Cartilage, Articular - transplantation; Cattle; Cell Count; Cell Survival - physiology; Chondrocytes - chemistry; Chondrocytes - physiology; Chondrocytes - transplantation; Collagen Type I - immunology; Collagen Type II - immunology; Collagenases - therapeutic use; Connective tissue diseases; Enzymes; Frozen Sections; Health aspects; Hyaluronoglucosaminidase - therapeutic use; Methods; Mice; Mice, Inbred BALB C; Mice, Nude; Models, Animal; Orthopedic surgery; Transplantation of organs, tissues, etc; Transplantation, Heterologous - methods; Netherlands
• ISSN: 1478-6354; 1478-6362; 1478-6354
• DOI: 10.1186/ar1216

The objective of the present study was to investigate whether treatment of articular cartilage with hyaluronidase and collagenase enhances histological and mechanical integration of a cartilage graft into a defect. Discs of 3 mm diameter were taken from 8-mm diameter bovine cartilage explants. Both discs and annulus were either treated for 24 hours with 0.1% hyaluronidase followed by 24 hours with 10 U/ml collagenase or left untreated (controls). Discs and annulus were reassembled and implanted subcutaneously in nude mice for 5 weeks. Integration of disc with surrounding cartilage was assessed histologically and tested biomechanically by performing a push-out test. After 5 weeks a significant increase in viable cell counts was seen in wound edges of the enzyme-treated group as compared with controls. Furthermore, matrix integration (expressed as a percentage of the total interface length that was connected; mean +/- standard error) was 83 +/- 15% in the treated samples versus 44 +/- 40% in the untreated controls. In the enzyme-treated group only, picro-Sirius Red staining revealed collagen crossing the interface perpendicular to the wound surface. Immunohistochemical analyses demonstrated that the interface tissue contained cartilage-specific collagen type II. Collagen type I was found only in a small region of fibrous tissue at the level of the superficial layer, and collagen type III was completely absent in both groups. A significant difference in interfacial strength was found using the push-out test: 1.32 +/- 0.15 MPa in the enzyme-treated group versus 0.84 +/- 0.14 MPa in the untreated controls. The study shows that enzyme treatment of cartilage wounds increases histological integration and improves biomechanical bonding strength. Enzymatic treatment may represent a promising addition to current techniques for articular cartilage repair.