A novel micro-groove impedance sensor for 3D cell viability monitoring and high-throughput drug screening

Drug screening is traditionally based on the pharmacodynamic models from 2D cell culture or animal experiments. Recently, three-dimensional (3D) tumor cell models have attracted increasing interest due to their great advantages in simulating more accurately the heterogeneous tumor behavior in vivo. Drug screening based on 3D cells can provide more accurate efficacy results. However, it is difficult to realize real-time and label-free monitoring of 3D cell viability by common imaging techniques. To solve this technical difficulty, a novel micro-groove impedance sensor (MGIS) was specially developed for 3D cell viability real-time monitoring. Precultured 3D spheroids cells are trapped in the micro-cavity with opposite gold electrodes for the in-situ impedance measurement. The presence of 3D spheroid cells will lead to the change of electron transfer efficiency on the electrode surface, which will lead to the change of impedance. When antitumor drugs act on the spheroid cells, the spheroids will cleave and the impedance will decrease. In order to verify the accuracy of MGIS chip, we adopted standard live/dead fluorescence staining to validate the activity of 3D cells. Furthermore, anti-tumor drug sensitivity tests were conducted to validate the drug screening ability of MGIS plat-form. All the results demonstrate that the MGIS is able to monitoring 3D cell viability and drug screening.