Cartilage cells are normally studied under atmospheric pressure conditions and without loading. However, since cartilage exists in a condition of reduced @entity26 and intermittent hydrostatic pressure we hypothesized lower partial @entity26 pressures ( @entity4095 ) and different intermittent hydrostatic pressures (IHP) would increase articular chondrocyte proliferation and matrix production and to stabilize chondrocyte phenotype in vitro. Monolayers of adult @entity291 articular chondrocytes were cultured under 5% or 21% @entity4095 in combination with IHP (0.2 MPa amplitude, frequencies 5/5s = 0.1 Hz, 30/2 or 2/30 min on/off loading). We measured proliferation (3H- @entity1014 incorporation) and collagen secretion (protein-binding assay, collagen type II-ELISA and immunocytochemical staining of pericellular collagen types I, II and IX). Reduced @entity4095 stimulated proliferation and collagen type II and IX secretion of chondrocytes in comparison to 21% @entity4095 . Additionally, collagen type I expression was delayed by low @entity4095 , indicating a stabilization of the cell phenotype. IHP 5/5s and 30/2 min inhibited proliferation but increased collagen secretion (pericellular collagen type IX was decreased). IHP 30/2 min delayed first expression of collagen type I. In contrast, IHP 2/30 min increased proliferation, but lowered collagen expression. All stimulating or inhibiting effects of @entity4095 and IHP were additive and vice versa. Reduced @entity4095 and different settings of IHP increased proliferation, collagen secretion, and phenotype stability of chondrocytes. The @entity26 - and IHP-induced effects were additive, suggesting that a combination of these parameters might be a useful tool in cartilage tissue engineering.

Combination of reduced XXXX tension and intermittent hydrostatic pressure: a useful tool in articular cartilage tissue engineering.

@entity26 :: ('MESH:D010100', 'Chemical') :: ['oxygen'] @entity291 :: ('9913', 'Species') :: ['bovine'] @entity4095 :: ('MESH:C093415', 'Chemical') :: ['PO2'] @entity1014 :: ('MESH:D013936', 'Chemical') :: ['thymidine']
@entity26 :: (MESH:D010100,Chemical) :: ['oxygen']
