MEMS Device to Monitor Biological Oxygen Uptake at Arrays of Single Cells and Small Cell Clusters

Oxygen uptake by a cell is indicative of metabolic processes which are modulated by extracellular stimuli and is characteristic of a cell's physiological status. In this work, a MEMS platform with an array of microsensors to monitor these processes at cell constructs is being developed. An array of Pt microring electrodes has been fabricated to quantitatively assess oxygen uptake by normal and pharmacologically manipulated BAC1.2F5 macrophage cells positioned at cell attachment sites inside the microrings. An amperometric pulsing protocol was implemented to reduce interference with cellular metabolism caused by depletion of oxygen during the measurement. We were able to detect changes as small as 1% in oxygen concentration in the vicinity of single cells and small cell clusters. Thus, the approach can be used for sensitive indication of oxygen uptake by cell(s) and its modulation by environmental factors such as pharmacological agents, and interaction with adjacent cells. Moreover, parallel experiments at different cell attachment sites are made feasible by the sensor array. This can provide multiple data sets for biostatistics in the same amount of time that is required to get a single data set.