Development of perfusion-based micro 3-D cell culture platform and its application for high throughput drug testing

This study reports a new perfusion-based, micro three-dimensional (3-D) cell culture platform for drug testing using enabling microfluidic technologies. The features of this cell culture platform include maintaining homogenous and stable culture environments, efficient medium delivery and cells/agarose (scaffold) loading; allowing realization of more precise and high-throughput cell culture-based assays. In this work, the perfusion-based, micro 3-D cell culture platform was designed and was fabricated based on SU-8 lithography and PDMS (poly-dimethylsiloxane) replication processes. The performance of the integrated pneumatic micropumps and cells/agarose loading mechanism were experimentally evaluated. The results show that in all of the 15 pneumatic micropumps studied, the medium delivery mechanism was able to provide a uniform flow output at flow rates ranging from 3.6 μl/h to 439.0 μl/h, depending on the applied pulsation frequency of the micropumps. In addition, the cell/agarose (scaffold) loading mechanism was proven to be able to perform sample loading tasks precisely and accurately in all of the 15 microbioreactors investigated with adjustable loading volumes of 0.22 μl, 0.18 μl and 0.14 μl at applied air pressures of 10 psi, 12 psi and 15 psi, respectively, in the microvalves. Furthermore, anti-cancer drug testing was successfully demonstrated using the proposed culture platform and fluorescent microscopic observation. As a whole, because of miniaturization, not only does this perfusion 3-D cell culture platform provide a homogenous and steady cell culture environment, but it also reduces the need for human intervention. Moreover, due to the integrated pumping of the medium and the cell/agarose (scaffold) loading mechanisms, time efficient and economical research work can be achieved. These characteristics are found particularly useful for high-precision and high-throughput 3-D cell culture-based drug testing.