Effect of reduced oxygen tension and long-term mechanical stimulation on chondrocyte-polymer constructs

Wernike, Ellen; Li, Zhen; Alini, Mauro; Grad, Sibylle (2008). Effect of reduced oxygen tension and long-term mechanical stimulation on chondrocyte-polymer constructs. Cell and tissue research, 331(2), pp. 473-83. Heidelberg: Springer 10.1007/s00441-007-0500-9

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We have investigated the influence of long-term confined dynamic compression and surface motion under low oxygen tension on tissue-engineered cell-scaffold constructs. Porous polyurethane scaffolds (8 mm x 4 mm) were seeded with bovine articular chondrocytes and cultured under normoxic (21% O(2)) or hypoxic (5% O(2)) conditions for up to 4 weeks. By means of our joint-simulating bioreactor, cyclic axial compression (10-20%; 0.5 Hz) was applied for 1 h daily with a ceramic ball, which simultaneously oscillated over the construct surface (+/-25 degrees; 0.5 Hz). Culture under reduced oxygen tension resulted in an increase in mRNA levels of type II collagen and aggrecan, whereas the expression of type I collagen was down-regulated at early time points. A higher glycosaminoglycan content was found in hypoxic than in normoxic constructs. Immunohistochemical analysis showed more intense type II and weaker type I collagen staining in hypoxic than in normoxic cultures. Type II collagen gene expression was slightly elevated after short-term loading, whereas aggrecan mRNA levels were not influenced by the applied mechanical stimuli. Of importance, the combination of loading and low oxygen tension resulted in a further down-regulation of collagen type I mRNA expression, contributing to the stabilization of the chondrocytic phenotype. Histological results confirmed the beneficial effect of mechanical loading on chondrocyte matrix synthesis. Thus, mechanical stimulation combined with low oxygen tension is an effective tool for modulating the chondrocytic phenotype and should be considered when chondrocytes or mesenchymal stem cells are cultured and differentiated with the aim of generating cartilage-like tissue in vitro.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > Pre-clinic Human Medicine > BioMedical Research (DBMR) > DBMR Forschung Mu35 > Forschungsgruppe Knochenbiologie & Orthopädische Forschung
04 Faculty of Medicine > Pre-clinic Human Medicine > BioMedical Research (DBMR) > DBMR Forschung Mu35 > Forschungsgruppe Knochenbiologie & Orthopädische Forschung

UniBE Contributor:

Wernike, Ellen

ISSN:

0302-766X

ISBN:

17957384

Publisher:

Springer

Language:

English

Submitter:

Factscience Import

Date Deposited:

04 Oct 2013 15:06

Last Modified:

04 May 2014 23:20

Publisher DOI:

10.1007/s00441-007-0500-9

PubMed ID:

17957384

Web of Science ID:

000252274800009

URI:

https://boris.unibe.ch/id/eprint/28545 (FactScience: 121263)

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