Cell Monitoring and Manipulation Systems (CMMSs) based on Glass Cell-Culture Chips (GC3s)

Abstract

We developed different types of glass cell-culture chips (GC3s) 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 µm were tested. After 3 weeks, the magnitudes of the determined action potentials were highest for pads of 25 µm in diameter and did not differ when the inter-pad distances were 100 or 170 µm. Using 25-µm diameter circular oxygen electrodes, the signal currents in the cell-culture media were found to range from approximately −0.08 nA (0% O2) to −2.35 nA (21% O2). 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 GC3s 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 GC3 system.

Surface Coatings Modulate the Differences in the Adhesion Forces of Eukaryotic and Prokaryotic Cells as Detected by Single Cell Force Microscopy

“…Silicon nitride is a common material for in vitro cell monitoring devices, but it is not yet as widely used in standard biological applications [3, 53, 54] although it does have similar MDF-enhancing properties to the common cell culture coating PEI.…”

“…They permit statements to be made on the kinetics of cell adhesion using mass and complex elasticity effects as well as viscoelastic effects at the cellular interfaces to the sensor surface [2]. In interdigitated electrode structures (IDES), cell adhesion is registered via the electric impedance, which changes when the number of cells or their degree of spreading alters the electrochemically effective surface of the IDES [3–5].…”

“…Ceramic silicon nitride is often used as an insulating layer in semiconductors and on conductive on-chip tracks of multielectrode arrays [3]. The positively charged, inorganic silicon nitride surfaces have been successfully used for cell culturing in lab-on-chip systems [20].…”

Organs-on-chip monitoring: sensors and other strategies

“…Not only identifying the cell density and viability but also investigation of cellular function by cultivation time and upon any stimulus are needed. So far, sensors for the purpose of monitoring cellular adhesion (49), detachment (50), death (51), response to osmotic stress (52), sepsis (53) have been developed based on widely used surface plasmon resonance (SPR) technique, photonic crystal fibers (54), and resonant waveguide grating EPIC ® systems (55). Contractile properties of cells, especially cardiomyocytes for heart-on-a-chip platforms is of great importance and it is reported to be affected by intracellular calcium secretion.…”

Editorial for Special Issue: Advances in Microfluidic Devices for Cell Handling and Analysis

“…Two reviews complete the special issue, one dealing with micro-controlled cell environment and monitoring [ 8 ] and other discussing recent developments of cell monitoring and manipulation systems onto glass substrate chips [ 9 ].…”