title: Cryopreservation and in vitro expansion of chondroprogenitor cells isolated from the superficial zone of articular cartilage.
abstract: Understanding the proliferation mechanisms of chondroprogenitor cells and their influence on cell differentiation is crucial in order to develop large-scale expansion processes for tissue engineering applications. Proliferation control mechanisms were mainly attributed to substrate limitation and cell-cell contact inhibition. The limiting substrates were found to be components of the FCS, with an optimal proliferation rate achieved in the presence of 40% FCS. In addition, the medium supply rate was found to be essential in reducing substrate limitation. In terms of FCS, 10 microL FCS cm(-2) h(-1) was the threshold feed rate required to prevent substrate limitation. Above this rate, maximum cell densities of 5.3 x 10(5) cells/cm2 were achieved, representing a 53-fold expansion. To reduce the need for high supply rates, the effect of specific growth factors was also investigated. Cell densities of 3.3 x 10(5) cells/cm2 were achieved in batch cultures using 40% FCS and 1 ng/mL TGF-beta1. Chondroprogenitor cells were expanded in this medium up to three passages without compromising their ability to differentiate and produce cartilage-like matrix in pellet cultures. In addition to substrate limitation, cell-cell contact, even at very sparse subconfluent densities, appeared capable of exerting some degree of growth inhibition. The cells exhibited deceleratory growth kinetics, characterized by a decrease of specific growth rates over time.
authors.affiliation: Department of Chemical Engineering, School of Engineering, University of Birmingham, Birmingham, B15 2TT, UK.
authors.forename: Juan M Melero
authors.initials: JM
authors.lastname: Martin
authors.forename: Mark
authors.initials: M
authors.lastname: Smith
authors.forename: Mohamed
authors.initials: M
authors.lastname: Al-Rubeai
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000166:cytology*; D002417:Cattle; D002452:Cell Count; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D015925:Cryopreservation / Q000379:methods*; D003470:Culture Media / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D010477:Perfusion / Q000379:methods; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods
chemical_list: D003470:Culture Media