title: Methods for producing scaffold-free engineered cartilage sheets from auricular and articular chondrocyte cell sources and attachment to porous tantalum.
abstract: Scaffold-free cartilage engineering techniques may provide a simple alternative to traditional methods employing scaffolds. We previously reported auricular chondrocyte-derived constructs for use in an engineered trachea model; however, the construct generation methods were not reported in detail. In this study, methods for cartilage construct generation from auricular and articular cell sources are described in detail, and the resulting constructs are compared for use in a joint resurfacing model. Attachment of cartilage sheets to porous tantalum is also investigated as a potential vehicle for future attachment to subchondral bone. Large scaffold-free cartilage constructs were produced from culture-expanded chondrocytes from skeletally mature rabbits, and redifferentiated in a chemically-defined culture medium. Auricular constructs contained more glycosaminoglycan (39.6±12.7 vs. 9.7±1.9 μg/mg wet weight, mean and standard deviation) and collagen (2.7±0.45 vs. 1.1±0.2 μg/mg wet weight, mean and standard deviation) than articular constructs. Aggregate modulus was also higher for auricular constructs vs. articular constructs (0.23±0.07 vs. 0.12±0.03 MPa, mean and standard deviation). Attachment of constructs to porous tantalum was achieved by neocartilage ingrowth into tantalum pores. These results demonstrate that large scaffold-free neocartilage constructs can be produced from mature culture-expanded chondrocytes in a chemically-defined medium, and that these constructs can be attached to porous tantalum.
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University , Cleveland, Ohio. ; Department of Orthopaedics, Case Western Reserve University , Cleveland, Ohio. ; Hope Heart Matrix Biology Program, Benaroya Research Institute , Seattle, Washington.
authors.forename: G Adam
authors.initials: GA
authors.lastname: Whitney
authors.forename: Hisashi
authors.initials: H
authors.lastname: Mera
authors.forename: Mark
authors.initials: M
authors.lastname: Weidenbecher
authors.forename: Amad
authors.initials: A
authors.lastname: Awadallah
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Mansour
authors.forename: James E
authors.initials: JE
authors.lastname: Dennis
keywords: biomaterials; cell culture; regeneration; tissue engineering