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Gas exchange is essential for bioreactor cultivation of tissue engineered cartilage
Author(s) -
Obradovic Bojana,
Carrier Rebecca L.,
VunjakNovakovic Gordana,
Freed Lisa E.
Publication year - 1999
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/(sici)1097-0290(19990420)63:2<197::aid-bit8>3.0.co;2-2
Subject(s) - bioreactor , oxygen tension , anaerobic exercise , metabolism , chemistry , oxygen , biochemistry , cartilage , anaerobic glycolysis , tissue culture , carbohydrate metabolism , cellular respiration , carbon dioxide , tissue engineering , cell culture , chondrogenesis , cell , in vitro , glycolysis , biology , anatomy , organic chemistry , physiology , genetics , mitochondrion
Tissue engineered cartilage can be grown in vitro if the necessary physical and biochemical factors are present in the tissue culture environment. Cell metabolism and tissue composition were studied for engineered cartilage cultured for 5 weeks using bovine articular chondrocytes, polymer scaffolds (5 mm diameter × 2 mm thick fibrous discs), and rotating bioreactors. Medium pH and concentrations of oxygen, carbon dioxide, glucose, lactate, ammonia, and glycosoaminoglycan (GAG) were varied by altering the exchange rates of gas and medium in the bioreactors. Cell–polymer constructs were assessed with respect to histomorphology, biochemical composition and metabolic activity. Low oxygen tension (∼40 mmHg) and low pH (∼6.7) were associated with anaerobic cell metabolism (yield of lactate on glucose, Y L/G , of 2.2 mol/mol) while higher oxygen tension (∼80 mmHg) and higher pH (∼7.0) were associated with more aerobic cell metabolism ( Y L/G of 1.65–1.79 mol/mol). Under conditions of infrequent medium replacement (50% once per week), cells utilized more economical pathways such that glucose consumption and lactate production both decreased, cell metabolism remained relatively aerobic ( Y L/G of 1.67 mol/mol) and the resulting constructs were cartilaginous. More aerobic conditions generally resulted in larger constructs containing higher amounts of cartilaginous tissue components, while anaerobic conditions suppressed chondrogenesis in 3D tissue constructs. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 63: 197–205, 1999.