Study Of Cell Drug Metabolism And Cell Signaling On Microfluidic Device

The thesis focused on the urgent requirement of cell analysis in the field of lifesciences, and the aim of solving the problems in traditional cell analysis methods. Wecarried out cell-based researches related to drug metabolism and cell communication onmicrofluidic device. The contents were summarized as follows:1. We developed a microfluidic device for the imitation of drug metabolism in humanliver and its cytotoxicity on cells. The integrated microfluidic device consists of threesections:(1) bioreactors containing poly (ethylene) glycol (PEG) hydrogel encapsulatedhuman liver microsomes (HLMs);(2) cell culture chambers for cytotoxicity assay; and(3) integrated micro solid-phase extraction (SPE) columns to desalt and concentrate theproducts of enzymatic reaction. To verify the feasibility of the integrated microchip, westudied uridine5’-diphosphate-glucuronosyltransferase (UGT) metabolism ofacetaminophen (AP) and the cytotoxicity of products on HepG2cells. The products ofthe reaction in one region were injected into the cell culture chamber for cytotoxicityassay, while those in another region were directly detected online with an electrosprayionization quadrupole time-of-flight mass spectrometer (ESI-Q-TOF MS) aftermicro-SPE pre-treatment. Semiquantitative analysis achieved in the experiments couldbe related to the drug-induced HepG2cell cytotoxicity. Total analysis time for oneproduct was about30min and only less than4μg HLM protein was required for onereaction region. The results demonstrated that the established platform could be used toimitate drug metabolism occurring in the human liver, thereby replacing animalexperiments in the near future. In addition, the integrated microchip will be a useful toolfor drug metabolism studies and cytotoxicity assays, which are pivotal in drugdevelopment.2. We have developed an integrated microfluidic chip coupled with ESI-Q-TOF MSfor cell-to-cell communication study in vitro, and a “Surface Tension Valve” wasdesigned on the microdevice to control cell communication. We believed that the“Surface Tension Valve” presented first in this work, requiring no extra equipment andenergy, would be a useful design on microfluidic chip. Contrast to reported method, weused continues incubation, which was closer to the human environment, instead of static incubation. The combined system was proven to be useful for high-throughput MSdetection of signaling and the final metabolites, which were very important for cellcommunication research.