The importance of bicarbonate and nonbicarbonate buffer systems in batch and continuous flow bioreactors for articular cartilage tissue engineering

Aasma A Khan, Denver C Surrao

Research output: Contribution to journalArticleResearchpeer-review

7 Citations (Scopus)

Abstract

In cartilage tissue engineering an optimized culture system, maintaining an appropriate extracellular environment (e.g., pH of media), can increase cell proliferation and extracellular matrix (ECM) accumulation. We have previously reported on a continuous-flow bioreactor that improves tissue growth by supplying the cells with a near infinite supply of medium. Previous studies have observed that acidic environments reduce ECM synthesis and chondrocyte proliferation. Hence, in this study we investigated the combined effects of a continuous culture system (bioreactor) together with additional buffering agents (e.g., sodium bicarbonate [NaHCO₃]) on cartilaginous tissue growth in vitro. Isolated bovine chondrocytes were grown in three-dimensional cultures, either in static conditions or in a continuous-flow bioreactor, in media with or without NaHCO₃. Tissue constructs cultivated in the bioreactor with NaHCO₃-supplemented media were characterized with significantly increased (p<0.05) ECM accumulation (glycosaminoglycans a 98-fold increase; collagen a 25-fold increase) and a 13-fold increase in cell proliferation, in comparison with static cultures. Additionally, constructs grown in the bioreactor with NaHCO₃-supplemented media were significantly thicker than all other constructs (p<0.05). Further, the chondrocytes from the primary construct expanded and synthesized ECM, forming a secondary construct without a separate expansion phase, with a diameter and thickness of 4 mm and 0.72 mm respectively. Tissue outgrowth was negligible in all other culturing conditions. Thus this study demonstrates the advantage of employing a continuous flow bioreactor coupled with NaHCO₃ supplemented media for articular cartilage tissue engineering.

Original languageEnglish
Pages (from-to)358-68
Number of pages11
JournalTissue Engineering - Part C: Methods
Volume18
Issue number5
DOIs
Publication statusPublished - May 2012
Externally publishedYes

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Cartilage
Articular Cartilage
Bioreactors
Tissue Engineering
Bicarbonates
Tissue engineering
Buffers
Extracellular Matrix
Chondrocytes
Tissue
Cell proliferation
Cell Proliferation
Sodium bicarbonate
Sodium Bicarbonate
Growth
Glycosaminoglycans
Cell culture
Collagen

Cite this

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title = "The importance of bicarbonate and nonbicarbonate buffer systems in batch and continuous flow bioreactors for articular cartilage tissue engineering",
abstract = "In cartilage tissue engineering an optimized culture system, maintaining an appropriate extracellular environment (e.g., pH of media), can increase cell proliferation and extracellular matrix (ECM) accumulation. We have previously reported on a continuous-flow bioreactor that improves tissue growth by supplying the cells with a near infinite supply of medium. Previous studies have observed that acidic environments reduce ECM synthesis and chondrocyte proliferation. Hence, in this study we investigated the combined effects of a continuous culture system (bioreactor) together with additional buffering agents (e.g., sodium bicarbonate [NaHCO₃]) on cartilaginous tissue growth in vitro. Isolated bovine chondrocytes were grown in three-dimensional cultures, either in static conditions or in a continuous-flow bioreactor, in media with or without NaHCO₃. Tissue constructs cultivated in the bioreactor with NaHCO₃-supplemented media were characterized with significantly increased (p<0.05) ECM accumulation (glycosaminoglycans a 98-fold increase; collagen a 25-fold increase) and a 13-fold increase in cell proliferation, in comparison with static cultures. Additionally, constructs grown in the bioreactor with NaHCO₃-supplemented media were significantly thicker than all other constructs (p<0.05). Further, the chondrocytes from the primary construct expanded and synthesized ECM, forming a secondary construct without a separate expansion phase, with a diameter and thickness of 4 mm and 0.72 mm respectively. Tissue outgrowth was negligible in all other culturing conditions. Thus this study demonstrates the advantage of employing a continuous flow bioreactor coupled with NaHCO₃ supplemented media for articular cartilage tissue engineering.",
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The importance of bicarbonate and nonbicarbonate buffer systems in batch and continuous flow bioreactors for articular cartilage tissue engineering. / Khan, Aasma A; Surrao, Denver C.

In: Tissue Engineering - Part C: Methods, Vol. 18, No. 5, 05.2012, p. 358-68.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

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AU - Khan, Aasma A

AU - Surrao, Denver C

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