Hypoxia and flow perfusion modulate proliferation and gene expression of articular chondrocytes on porous scaffolds

The combination of reduced oxygen tension and flow perfusion bioreactor culture is investigated for its effect on the proliferation, glycosaminoglycan production, and chondrogenic gene expression of bovine articular chondrocytes on porous polymer scaffolds. It was hypothesized that the combination of such factors would more closely replicate the in situ environment of these cells, leading to improvements in the cell phenotype. Chondrocytes were seeded onto electrospun poly(epsilon-caprolactone) scaffolds and cultured in static or perfusion culture in either normoxic or hypoxic conditions for 6days. Results demonstrated that the combination of hypoxic and perfusion culture led to an increase in chondrocyte proliferation and glycosaminoglycan production, as well as an improvement in the ratio of collagen II/I gene expression over perfusion culture alone. The results demonstrate the need to combine multiple signals in vitro, in order to improve tissue growth by more closely replicating the native environment of cells. (c) 2013 American Institute of Chemical Engineers AIChE J, 59: 3158-3166, 2013