Cell Monitoring And Manipulation Systems (Cmmss) Based On Glass Cell-Culture Chips (Gc(3)S)

We developed different types of glass cell-culture chips (GC(3)s) for culturing cells for microscopic observation in open media-containing troughs or in microfluidic structures. Platinum sensor and manipulation structures were used to monitor physiological parameters and to allocate and permeabilize cells. Electro-thermal micro pumps distributed chemical compounds in the microfluidic systems. The integrated temperature sensors showed a linear, Pt1000-like behavior. Cell adhesion and proliferation were monitored using interdigitated electrode structures (IDESs). The cell-doubling times of primary murine embryonic neuronal cells (PNCs) were determined based on the IDES capacitance-peak shifts. The electrical activity of PNC networks was detected using multi-electrode arrays (MEAs). During seeding, the cells were dielectrophoretically allocated to individual MEAs to improve network structures. MEA pads with diameters of 15, 20, 25, and 35 mu m were tested. After 3 weeks, the magnitudes of the determined action potentials were highest for pads of 25 mu m in diameter and did not differ when the inter-pad distances were 100 or 170 mu m. Using 25-mu m diameter circular oxygen electrodes, the signal currents in the cell-culture media were found to range from approximately -0.08 nA (0% O-2) to -2.35 nA (21% 02). It was observed that 60-nm thick silicon nitride-sensor layers were stable potentiometric pH sensors under cell-culture conditions for periods of days. Their sensitivity between pH 5 and 9 was as high as 45 mV per pH step. We concluded that sensorized GC(3)s are potential animal replacement systems for purposes such as toxicity pre-screening. For example, the effect of mefloquine, a medication used to treat malaria, on the electrical activity of neuronal cells was determined in this study using a GC(3) system.