Abstract:

Fluid shear stress as a common form of biomechanics plays an important role in maintaining cell morphology, cell secretion and function in microenvironment. Herein, we proposed a microfluidic platform which could generate four different intensities of fluid shear to study the cellular effects of fluid shear stress on chondrocyte phenotype under low flow condition. Under low flow condition, the primary chondrocytes could keep good activity and morphology. With the increase of shear force, the expressions of collagen type Ⅱ and aggrecan in primary chondrocyte were up-regulated. At the same time, the expressions of collagen type Ⅰ increased. These results indicated that fluid shear stress could improve chondrocyte phenotype maintaining. Moreover, increase of the shear force also accelerated the dedifferentiation of chondrocytes. Tumor necrosis factor-α (TNF-α) plays a negative role in maintaining chondrocyte phenotype. The interaction effect of fluid shear stress and TNF-α on chondrocyte phenotype was investigated on this platform. The results showed that under the combined effects of the shear force and TNF-α, the expressions of collagen type Ⅱ and aggrecan of chondrocytes were significantly down-regulated. This method provided a powerful platform for cartilage tissue engineering and osteoarthritis disease research, and gave a theoretical basis for the joint disease treatment and prevention.

Key words: (TNF-α), cartilage phenotype, fluid shear stress, microfluidic chip, tumor necrosis factor-&alpha