Effect of oxygen tension and alginate encapsulation on restoration of the differentiated phenotype of passaged chondrocytes.

The implantation of laboratory-grown tissue offers a valuable alternative approach to the treatment of cartilage defects. Procuring sufficient cell numbers for such tissue-engineered cartilage is a major problem since amplification of chondrocytes in culture typically leads to loss of normal cell ph...

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Main Authors: Murphy, C, Sambanis, A
Format: Journal article
Language:English
Published: 2001
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author Murphy, C
Sambanis, A
author_facet Murphy, C
Sambanis, A
author_sort Murphy, C
collection OXFORD
description The implantation of laboratory-grown tissue offers a valuable alternative approach to the treatment of cartilage defects. Procuring sufficient cell numbers for such tissue-engineered cartilage is a major problem since amplification of chondrocytes in culture typically leads to loss of normal cell phenotype yielding cartilage of inferior quality. In an effort to overcome this problem, we endeavored to regain the differentiated phenotype of chondrocytes after extensive proliferation in monolayer culture by modulating cell morphology and oxygen tension towards the in vivo state. Passaged cells were encapsulated in alginate hydrogel in an effort to regain the more rounded shape characteristic of differentiated chondrocytes. These cultures were exposed to reduced (5%-i.e., physiological), or control (20%) oxygen tensions. Both alginate encapsulation and reduced oxygen tension significantly upregulated collagen II and aggrecan core protein expression (differentiation markers). In fact, after 4 weeks in alginate at 5% oxygen, differentiated gene expression was comparable to primary chondrocytes. Collagen I expression (dedifferentiation marker) decreased dramatically after alginate entrapment, while reduced oxygen tension had no effect. It is concluded that alginate encapsulation and reduced oxygen tension help restore key differentiated phenotypic markers of passaged chondrocytes. These findings have important implications for cartilage tissue engineering, since they enable the increase in differentiated cell numbers needed for the in vitro development of functional cartilaginous tissue suitable for implantation.
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spelling oxford-uuid:d4a7b892-c25e-4db5-8704-ad70c3dfbb632022-03-27T08:20:13ZEffect of oxygen tension and alginate encapsulation on restoration of the differentiated phenotype of passaged chondrocytes.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:d4a7b892-c25e-4db5-8704-ad70c3dfbb63EnglishSymplectic Elements at Oxford2001Murphy, CSambanis, AThe implantation of laboratory-grown tissue offers a valuable alternative approach to the treatment of cartilage defects. Procuring sufficient cell numbers for such tissue-engineered cartilage is a major problem since amplification of chondrocytes in culture typically leads to loss of normal cell phenotype yielding cartilage of inferior quality. In an effort to overcome this problem, we endeavored to regain the differentiated phenotype of chondrocytes after extensive proliferation in monolayer culture by modulating cell morphology and oxygen tension towards the in vivo state. Passaged cells were encapsulated in alginate hydrogel in an effort to regain the more rounded shape characteristic of differentiated chondrocytes. These cultures were exposed to reduced (5%-i.e., physiological), or control (20%) oxygen tensions. Both alginate encapsulation and reduced oxygen tension significantly upregulated collagen II and aggrecan core protein expression (differentiation markers). In fact, after 4 weeks in alginate at 5% oxygen, differentiated gene expression was comparable to primary chondrocytes. Collagen I expression (dedifferentiation marker) decreased dramatically after alginate entrapment, while reduced oxygen tension had no effect. It is concluded that alginate encapsulation and reduced oxygen tension help restore key differentiated phenotypic markers of passaged chondrocytes. These findings have important implications for cartilage tissue engineering, since they enable the increase in differentiated cell numbers needed for the in vitro development of functional cartilaginous tissue suitable for implantation.
spellingShingle Murphy, C
Sambanis, A
Effect of oxygen tension and alginate encapsulation on restoration of the differentiated phenotype of passaged chondrocytes.
title Effect of oxygen tension and alginate encapsulation on restoration of the differentiated phenotype of passaged chondrocytes.
title_full Effect of oxygen tension and alginate encapsulation on restoration of the differentiated phenotype of passaged chondrocytes.
title_fullStr Effect of oxygen tension and alginate encapsulation on restoration of the differentiated phenotype of passaged chondrocytes.
title_full_unstemmed Effect of oxygen tension and alginate encapsulation on restoration of the differentiated phenotype of passaged chondrocytes.
title_short Effect of oxygen tension and alginate encapsulation on restoration of the differentiated phenotype of passaged chondrocytes.
title_sort effect of oxygen tension and alginate encapsulation on restoration of the differentiated phenotype of passaged chondrocytes
work_keys_str_mv AT murphyc effectofoxygentensionandalginateencapsulationonrestorationofthedifferentiatedphenotypeofpassagedchondrocytes
AT sambanisa effectofoxygentensionandalginateencapsulationonrestorationofthedifferentiatedphenotypeofpassagedchondrocytes