A facile cell-involved microfluidic platform for assessing risk of hepatotoxic chemicals via on-line monitoring of multi-indexes

Toxicity assessment is necessary in many fields, but the common animal experiments and traditional cell-based bioassays are endpoint tests and limited in the aspects of cost, complex operation, individual difference, etc. Herein, a cell-involved platform for facilely assessing risk of chemicals was established based on electrochemical biosensing and microfluidic technology. Through in situ monitoring responses of live cells cultivated in sensor chamber towards exterior chemical stimuli, a preliminary categorization of chemicals on reversibility of cell injury has been achieved. The device consists of two core units: a bioreactor and a cell metabolism monitoring chip (CMMC). The bioreactor is for culturing live cells and meanwhile delivering real-time electrochemical impedance of cells via a built-in interdigital electrode. The CMMC is connected to the bioreactor and the installed enzymatic screen-printed electrodes (SPEs) fulfill on-line detection of glucose (Glu) and lactic acid (LA) flowing out of the bioreactor. Impedance values have to do with cell growth and reproduction, while the amounts of Glu and LA reflect respiration state of cells. To test validity of the platform, HepG2 cells were cultured in the bioreactor and treated with five chemicals. The influence induced by these chemicals was studied by monitoring and analyzing the variations of three signals (cell adhesion, Glu uptake and LA generation). The whole system allows for preliminary understanding of toxicity and possible mechanism of chemicals acting on cells, which is also expected to be applied in varied fields including ecological safety, biomedicine, etc.