Osteocytes have been proposed as the mechanosensory cells during the process of bone adaption. In this thesis, a microfluidics chamber system (MCS) device was designed, fabricated and tested as a means to maximally simulate the in vivo osteocytic ultrastructure and reproduce the in vivo shear stress experienced by osteocyte, providing an ideal platform for in vitro study on osteocyte mechanotransduction. By employing a micropipette aspiration technique, single osteocyte adhesion and osteocytic process formation were achieved on PDMS with MCS structure. In this study, the involvement of sphingosine-1-phosphate (S1P) signaling pathway in osteocytes responding to oscillatory fluid flow (OFF) was also examined. Firstly, MLO-Y4 osteocytes like cells were demonstrated to express integrated and functional S1P cascade. By modulating S1P cascade components and testing a series of cellular outcomes, it was indicated that exogenous S1P, endogenous S1P and S1P receptor S1P2 were involved in the regulation of loading induced osteocytic responses.

Osteocytes have been proposed as the mechanosensory cells during the process of bone adaption. In this thesis, a microfluidics chamber system (MCS) device was designed, fabricated and tested as a means to maximally simulate the in vivo osteocytic ultrastructure and reproduce the in vivo shear stress experienced by osteocyte, providing an ideal platform for in vitro study on osteocyte mechanotransduction. By employing a micropipette aspiration technique, single osteocyte adhesion and osteocytic process formation were achieved on PDMS with MCS structure. In this study, the involvement of sphingosine-1-phosphate (S1P) signaling pathway in osteocytes responding to oscillatory fluid flow (OFF) was also examined. Firstly, MLO-Y4 osteocytes like cells were demonstrated to express integrated and functional S1P cascade. By modulating S1P cascade components and testing a series of cellular outcomes, it was indicated that exogenous S1P, endogenous S1P and S1P receptor S1P2 were involved in the regulation of loading induced osteocytic responses.