Comparison of Chondrogensis in Static and Perfused Bioreactor Culture

Authors

  • David Pazzano,

    1. Center for Tissue Engineering, University of Massachusetts Medical School, Worcester, Massachusetts 01655
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  • Kathi A. Mercier,

    1. Center for Tissue Engineering, University of Massachusetts Medical School, Worcester, Massachusetts 01655
    2. Departments of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01608
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  • John M. Moran,

    1. Center for Tissue Engineering, University of Massachusetts Medical School, Worcester, Massachusetts 01655
    2. Departments of Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01608
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  • Stephen S. Fong,

    1. Center for Tissue Engineering, University of Massachusetts Medical School, Worcester, Massachusetts 01655
    2. Departments of Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01608
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  • David D. DiBiasio,

    1. Departments of Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01608
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  • Jill X. Rulfs,

    1. Departments of Biology, Worcester Polytechnic Institute, Worcester, Massachusetts 01608
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  • Sean S. Kohles,

    1. Departments of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01608
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  • Lawrence J. Bonassar

    Corresponding author
    1. Center for Tissue Engineering, University of Massachusetts Medical School, Worcester, Massachusetts 01655
    • To whom correspondence should be addressed: Center for Tissue Engineering, Room 32–725, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655. Ph: (508) 856–5657. Fax: (508) 856–5911
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Abstract

As a result of the low yield of cartilage from primary patient harvests and a high demand for autologous cartilage for reconstructive surgery and structural repair, primary explant cartilage must be augmented by tissue engineering techniques. In this study, chondrocytes seeded on PLLA/PGA scaffolds in static culture and a direct perfusion bioreactor were biochemically and histologically analyzed to determine the effects of fluid flow and media pH on matrix assembly. A gradual media pH change was maintained in the bioreactor within 7.4−6.96 over 2 weeks compared to a more rapid decrease from 7.4 to 6.58 in static culture over 3 days. Seeded scaffolds subjected to 1 μm/s flow demonstrated a 118% increase (p < 0.05) in DNA content, a 184% increase (p < 0.05) in GAG content, and a 155% (p< 0.05) increase in hydroxyproline content compared to static culture. Distinct differences were noted in tissue morphology, including more intense staining for proteoglycans by safranin-O and alignment of cells in the direction of media flow. Culture of chondrocyte seeded matrices thus offers the possibility of rapid in vitro expansion of donor cartilage for the repair of structural defects, tracheal injury, and vascularized tissue damage.

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