Development of PDMS microbioreactor with well-defined and homogenous culture environment for chondrocyte 3-D culture.

Perfusion cell culture is believed to provide a stable culture environment due to the continuous supply of nutrients and removal of waste. However, the culture scales used in most cases were large, where the culture conditions can not be regarded as homogenous because of chemical gradients. To improve this, the concept of miniaturization is applied to 3-D cell culture. In this study, a simple perfusion microbioreactor was developed based on mass transport simulation to find out the reasonable culture scales with relatively lower chemical gradients. Besides, PDMS surface was treated with surfactant solution to reduce non-specific serum protein adsorption, which keeps the culture conditions steady. Chondrocyte 3-D culture using the proposed microbioreactors was compared with similar perfusion culture with a larger culture scale. Results showed that surfactant-treated PDMS surface could reduce serum protein adsorption by 85% over the native one. Also, microbioreactors were proved to provide a stable culture environment (e.g. pH) over the culture period. Cell culture scale of 200 microm thick culture construct was justified to have relatively lower chemical gradients than the larger scale perfusion culture. As a whole, the proposed culture system is capable of providing a well-defined and homogenous culture environment.