Low oxygen tension stimulates the redifferentiation of dedifferentiated adult human nasal chondrocytes1 1 Supported by IsoTis S.A.  J. Malda, Ph.D., C.A. van Blitterswijk, Ph.D., M. van Geffen, B.Sc., D.E. Martens, Ph.D., J. Tramper, Ph.D., J. Riesle, Ph.D.  Osteoarthritis and Cartilage  Volume 12, Issue 4, Pages 306-313 (April 2004) DOI: 10.1016/j.joca.2003.12.001

Fig. 1 Experimental design. Human nasal chondrocytes were isolated and expanded for 12 days in monolayer culture (two passages). To evaluate the post-expansion chondrocytic phenotype, the resulting cells were seeded in pellets and left for 3 days to form solid aggregates. Pellets were then transferred to a controlled bioreactor and cultured dynamically for up to 21 days. Osteoarthritis and Cartilage 2004 12, 306-313DOI: (10.1016/j.joca.2003.12.001)

Fig. 2 Photomicrographs of human septum nasal chondrocytes attached to the surfaces of polystyrene flasks after 3 days (A) and 7 days (B) of culturing. Scale bars represent 100μm (A) and 150μm (B). Osteoarthritis and Cartilage 2004 12, 306-313DOI: (10.1016/j.joca.2003.12.001)

Fig. 3 Photomicrographs of immunolocalized collagen types I (A), II (B) and IX (C) in monolayer cultures (first passage) after 12 days of cell expansion. Scale bars represent 100μm. Osteoarthritis and Cartilage 2004 12, 306-313DOI: (10.1016/j.joca.2003.12.001)

Fig. 4 Photomicrographs of safranin-O stained sections derived from dynamically cultured cell pellets after 7 days (A, D, G), 14 days (B, E, H) and 21 days (C, F, I) of culturing at 100% DO (A, B, C), 25% DO (D, E, F) and 5% DO (G, H, I). Scale bar represents 250μm. Osteoarthritis and Cartilage 2004 12, 306-313DOI: (10.1016/j.joca.2003.12.001)

Fig. 5 Graphs depicting the DNA (A) and GAG contents of cell pellets after 7 days, 14 days and 21 days of culturing at 100% DO, 25% DO or 5% DO. Mean values (±sd) are represented. At each sampling time, values for a particular DO tension that differ significantly (P<0.05) from the other two are indicated by an asterisk. Other significant differences are indicated by the symbols ‘δ’ and ‘ε’. Osteoarthritis and Cartilage 2004 12, 306-313DOI: (10.1016/j.joca.2003.12.001)

Fig. 6 Photomicrographs of immunolocalized 11-fibrau (A, B, C) and collagen type IX (D, E, F) on sections of cell pellets cultured dynamically for 14 days at 100% DO (A, D), 25% DO (B, E) or 5% DO (C, F). Scale bar represents 250μm. Osteoarthritis and Cartilage 2004 12, 306-313DOI: (10.1016/j.joca.2003.12.001)

Fig. 7 Photomicrographs of immunolocalized collagen types I (A, B, C) and II (D, E, F) on sections of cell pellets cultured dynamically for 21 days at 100% DO (A, D), 25% DO (B, E) and 5% DO (C, F). Scale bar represents 250μm. Osteoarthritis and Cartilage 2004 12, 306-313DOI: (10.1016/j.joca.2003.12.001)