title: Improved cartilage integration and interfacial strength after enzymatic treatment in a cartilage transplantation model.
abstract: 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.
authors.affiliation: Erasmus Orthopaedic Research Laboratory, Department of Orthopaedics, Erasmus University Medical Center, Rotterdam, The Netherlands. j.vandebreevaartbravenboer@erasmusmc.nl <j.vandebreevaartbravenboer@erasmusmc.nl>
authors.forename: Jarno
authors.initials: J
authors.lastname: van de Breevaart Bravenboer
authors.forename: Caroline D
authors.initials: CD
authors.lastname: In der Maur
authors.forename: P Koen
authors.initials: PK
authors.lastname: Bos
authors.forename: Louw
authors.initials: L
authors.lastname: Feenstra
authors.forename: Jan A N
authors.initials: JA
authors.lastname: Verhaar
authors.forename: Harrie
authors.initials: H
authors.lastname: Weinans
authors.forename: Gerjo J V M
authors.initials: GJ
authors.lastname: van Osch
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000737:chemistry / Q000187:drug effects* / Q000473:pathology / Q000637:transplantation*; D002417:Cattle; D002452:Cell Count; D002470:Cell Survival / Q000502:physiology; D019902:Chondrocytes / Q000737:chemistry / Q000502:physiology / Q000637:transplantation; D024042:Collagen Type I / Q000276:immunology; D024043:Collagen Type II / Q000276:immunology; D017364:Collagenases / Q000627:therapeutic use; D005629:Frozen Sections; D006821:Hyaluronoglucosaminidase / Q000627:therapeutic use; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D023421:Models, Animal; D014183:Transplantation, Heterologous / Q000379:methods*
chemical_list: D024042:Collagen Type I; D024043:Collagen Type II; D006821:Hyaluronoglucosaminidase; D017364:Collagenases