title: Human chondrocytes proliferate and produce matrix components in microcarrier suspension culture.
abstract: Chondrocytes propagated in monolayer culture proliferate and change into 'fibroblastoid'-like cells. This change is characterized by a shift in production of collagen type II to I and from high- to low-molecular-weight proteoglycans. When propagated in three-dimensional culture, chondrocytes have limited ability to divide but re-express their original characteristics. The goal of the present study was to determine whether a microcarrier suspension culture system would support chondrocyte proliferation and phenotype expression. Our experiments indicate that a collagen type I microcarrier (cellagen) best supported chondrocyte proliferation and phenotype expression. Cells in cellagen microcarriers multiplied at least twentyfold within 2 weeks and had doubling times of 2 to 3 d. Viable and metabolically active cells were retrieved with ease. The harvested chondrocytes had no detectable staining for collagen type I and stained intensely for collagen type II. Our studies demonstrate that the microcarrier suspension culture system supports growth and enhances expression of the 'chondrocytic' phenotype. Attachment to a constrained surface and the fluid shear forces on the microcarriers during suspension culture may have helped chondrocytes to reacquire their rounded shape and produce cartilage matrix components.
authors.affiliation: Johns Hopkins University, Department of Orthopaedic Surgery, Baltimore, MD.
authors.forename: C
authors.initials: C
authors.lastname: Frondoza
authors.forename: A
authors.initials: A
authors.lastname: Sohrabi
authors.forename: D
authors.initials: D
authors.lastname: Hungerford
mesh_terms: D001672:Biocompatible Materials; D002358:Cartilage, Articular / Q000166:cytology* / Q000378:metabolism*; D002448:Cell Adhesion; D018929:Cell Culture Techniques / Q000379:methods*; D002455:Cell Division; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis; D004247:DNA / Q000096:biosynthesis; D003911:Dextrans; D005109:Extracellular Matrix / Q000378:metabolism*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010641:Phenotype; D011509:Proteoglycans / Q000096:biosynthesis; D013583:Synovial Membrane / Q000166:cytology / Q000378:metabolism
chemical_list: D001672:Biocompatible Materials; D003911:Dextrans; D011509:Proteoglycans; D003094:Collagen; D004247:DNA