Articular cartilage mechanical and biochemical property relations before and after in vitro growth

Ficklin, Timothy; Thomas, Gregory; Barthel, James C.; Asanbaeva, Anna; Thonar, Eugene J.; Masuda, Koichi; Chen, Albert C.; Sah, Robert L.; Davol, Andrew; Klisch, Stephen M.

doi:10.1016/j.jbiomech.2007.06.005

« Previous Next »Journal of Biomechanics
Volume 40, Issue 16 , Pages 3607-3614, 2007

Articular cartilage mechanical and biochemical property relations before and after in vitro growth

Timothy Ficklin
- Department of Mechanical Engineering, California Polytechnic State University, San Luis Obispo, CA 93407, USA
Gregory Thomas
- Department of Mechanical Engineering, California Polytechnic State University, San Luis Obispo, CA 93407, USA
James C. Barthel
- Department of Mechanical Engineering, California Polytechnic State University, San Luis Obispo, CA 93407, USA
Anna Asanbaeva
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
Eugene J. Thonar
- Departments of Biochemistry and Orthopedic Surgery, Rush University Medical Center, Chicago, IL, USA
- Department of Internal Medicine, Rush University Medical Center, Chicago, IL, USA
Koichi Masuda
- Departments of Biochemistry and Orthopedic Surgery, Rush University Medical Center, Chicago, IL, USA
Albert C. Chen
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
Robert L. Sah
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
Andrew Davol
- Department of Mechanical Engineering, California Polytechnic State University, San Luis Obispo, CA 93407, USA
Stephen M. Klisch
- Department of Mechanical Engineering, California Polytechnic State University, San Luis Obispo, CA 93407, USA
- Corresponding author. Tel.: +18057561308; fax: +18057561137.

Accepted 6 June 2007. published online 15 July 2007.

Abstract

The aim of this study was to design in vitro growth protocols that can comprehensively quantify articular cartilage structure–function relations via measurement of mechanical and biochemical properties. Newborn bovine patellofemoral groove articular cartilage explants were tested sequentially in confined compression (CC), unconfined compression (UCC), and torsional shear before (D0, i.e. day zero) and after (D14, i.e. day 14) unstimulated in vitro growth. The contents of collagen (COL), collagen-specific pyridinoline (PYR) crosslinks, glycosaminoglycan, and DNA significantly decreased during in vitro growth; consequently, a wide range of biochemical properties existed for investigating structure–function relations when pooling the D0 and D14 groups. All D0 mechanical properties were independent of compression strain while only Poisson's ratios were dependent on direction (i.e. anisotropic). Select D0 and D14 group mechanical properties were correlated with biochemical measures; including (but not limited to) results that CC/UCC moduli and UCC Poisson's ratios were correlated with COL and PYR. COL network weakening during in vitro growth due to reduced COL and PYR was accompanied by reduced CC/UCC moduli and increased UCC Poisson's ratios.

Keywords: Cartilage, Growth, Collagen, Crosslinks, Biomechanics