title: Visual histological grading system for the evaluation of in vitro-generated neocartilage.
abstract: Here we present the development of a visual evaluation system for routine assessment of in vitro-engineered cartilaginous tissue. Neocartilage was produced by culturing human articular chondrocytes in pellet culture systems or in a scaffold-free bioreactor system. All engineered tissues were embedded in paraffin and were sectioned and stained with Safranin O-fast green. The evaluation of each sample was broken into 3 categories (uniformity and intensity of Safranin O stain, distance between cells/amount of matrix produced, and cell morphology), and each category had 4 components with a score ranging from 0 to 3. Three observers evaluated each sample, and the new system was independently tested against an objective computer-based histomorphometry system. Pellets were also assessed biochemically for glycosaminoglycan (GAG) content. Pellet histology scores correlated significantly with GAG contents and were in agreement with the computer-based histomorphometry system. This system allows a valid and rapid assessment of in vitro-generated cartilaginous tissue that has a relevant association with objective parameters indicative of cartilage quality.
authors.affiliation: Osteoarticular Research Group, Institute of Pathology, University of Bern, Bern, Switzerland.
authors.forename: Shawn Patrick
authors.initials: SP
authors.lastname: Grogan
authors.forename: Andrea
authors.initials: A
authors.lastname: Barbero
authors.forename: Verena
authors.initials: V
authors.lastname: Winkelmann
authors.forename: Franz
authors.initials: F
authors.lastname: Rieser
authors.forename: James S
authors.initials: JS
authors.lastname: Fitzsimmons
authors.forename: Shawn
authors.initials: S
authors.lastname: O'Driscoll
authors.forename: Ivan
authors.initials: I
authors.lastname: Martin
authors.forename: Pierre
authors.initials: P
authors.lastname: Mainil-Varlet
mesh_terms: D002358:Cartilage, Articular / Q000166:cytology* / Q000502:physiology*; D006801:Humans; D023822:Tissue Engineering