The Interplay between Chondrocyte Redifferentiation Pellet Size and Oxygen Concentration

Babur, Betul Kul, Ghanavi, Parisa, Levett, Peter, Lott, William B., Klein, Travis, Cooper-White, Justin J., Crawford, Ross and Doran, Michael R. (2013) The Interplay between Chondrocyte Redifferentiation Pellet Size and Oxygen Concentration. PLoS One, 8 3: e58865.1-e58865.12. doi:10.1371/journal.pone.0058865

Author Babur, Betul Kul
Ghanavi, Parisa
Levett, Peter
Lott, William B.
Klein, Travis
Cooper-White, Justin J.
Crawford, Ross
Doran, Michael R.
Title The Interplay between Chondrocyte Redifferentiation Pellet Size and Oxygen Concentration
Journal name PLoS One   Check publisher's open access policy
ISSN 1932-6203
Publication date 2013-03-01
Year available 2013
Sub-type Article (original research)
DOI 10.1371/journal.pone.0058865
Open Access Status DOI
Volume 8
Issue 3
Start page e58865.1
End page e58865.12
Total pages 12
Place of publication San Francisco, CA United States
Publisher Public Library of Science
Language eng
Formatted abstract
Chondrocytes dedifferentiate during ex vivo expansion on 2-dimensional surfaces. Aggregation of the expanded cells into 3-dimensional pellets, in the presence of induction factors, facilitates their redifferentiation and restoration of the chondrogenic phenotype. Typically 1×105-5×105 chondrocytes are aggregated, resulting in "macro" pellets having diameters ranging from 1-2 mm. These macropellets are commonly used to study redifferentiation, and recently macropellets of autologous chondrocytes have been implanted directly into articular cartilage defects to facilitate their repair. However, diffusion of metabolites over the 1-2 mm pellet length-scales is inefficient, resulting in radial tissue heterogeneity. Herein we demonstrate that the aggregation of 2×105 human chondrocytes into micropellets of 166 cells each, rather than into larger single macropellets, enhances chondrogenic redifferentiation. In this study, we describe the development of a cost effective fabrication strategy to manufacture a microwell surface for the large-scale production of micropellets. The thousands of micropellets were manufactured using the microwell platform, which is an array of 360×360 μm microwells cast into polydimethylsiloxane (PDMS), that has been surface modified with an electrostatic multilayer of hyaluronic acid and chitosan to enhance micropellet formation. Such surface modification was essential to prevent chondrocyte spreading on the PDMS. Sulfated glycosaminoglycan (sGAG) production and collagen II gene expression in chondrocyte micropellets increased significantly relative to macropellet controls, and redifferentiation was enhanced in both macro and micropellets with the provision of a hypoxic atmosphere (2% O2). Once micropellet formation had been optimized, we demonstrated that micropellets could be assembled into larger cartilage tissues. Our results indicate that micropellet amalgamation efficiency is inversely related to the time cultured as discreet microtissues. In summary, we describe a micropellet production platform that represents an efficient tool for studying chondrocyte redifferentiation and demonstrate that the micropellets could be assembled into larger tissues, potentially useful in cartilage defect repair.
Keyword Human Articular Chondrocytes
Mesenchymal stem cells
Microcarriers Enhances Redifferentiation
Formation In Vitro
Hyaluronic Acid
Cartilage Defects
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2014 Collection
Australian Institute for Bioengineering and Nanotechnology Publications
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Citation counts: TR Web of Science Citation Count  Cited 23 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 24 times in Scopus Article | Citations
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Created: Sun, 28 Apr 2013, 10:04:34 EST by System User on behalf of Aust Institute for Bioengineering & Nanotechnology