Determination of patient-derived brain cancer cell respiration rates with chip-based microsensors

Studying alterations in metabolic activity and the biochemical microenvironment of cells, such as hypoxia, is essential in cancer research. Electrochemical microsensors allow the fast and spatially resolved measurement of oxygen levels in real-time. We report on the determination of cellular respiration rates of primary patient-derived glioblastoma brain cancer cells on-chip, using a multi-channel microsensor platform. Cells grow directly on the sensor chip with integrated electrochemical oxygen sensors. Patient-derived human glioblastoma brain cancer cells were successfully cultured on the platform. By reducing the volume of culture medium below $10 \mu \mathrm{l}$, we are able to measure cellular oxygen consumption within minutes. Cellular respiration rates were determined reproducibly, and the values between 2 and 5 fmol per cell per min corresponded well to previously reported values for different cancer cell models. We demonstrated that our microsensor can provide valuable online information on cell metabolism, which is highly attractive in cancer research, where metabolic transformations are essential to the understanding of tumor progression and the development of novel treatment strategies.