Study Of Tumor Cells Capture And Drug Screening Assays On Microfluid Cell Chips

The microfluidics has the unique advantages, such as high throughput, highefficiency, in vivo-like microenvironments and so on, low consumption of solvent, inthe study of life sciences. Nowadays, numerous studies have reported the use of themicrofluidics in cell sorting, cell culture, cell-based drug screening and so on. However,related researches such as chip design, microfluidic control, test efficiency and accuracyare not perfect. In order to improve the shortage, this paper designed and built amicrofluidic chip platform for the research of tumor cell capture and drug screening,and related research had potential practical significance.The topics of this dissertation are presented below:1. Based on the related theories and achievements at domestic and abroad,microfluidic cell chips composed of integrated magnetic micro-columns and a6×6array ofmicrochambers were designed and fabricated, respectively. By the high-gradientmagnetic field induced by magnetic structure ararry, magnetie beads were captured bythese micro magnetic structures; The array of6×6cell culture chambers had thepotential in cell-based research,such as high throughput drug screening.2. Hep-G2cells were magnetically labeled via endocytosis and immune method,respectively, then the microfluidic cell chip composed of integrated magnetic micro-columnswas uesd to capture magnetically labeled Hep-G2cells from blood cells. Resultsshowed the optimized dosage of magnetic beads(0.2mg) and the optimized incubationtime (endocytosis,6h and immune method30min). If magnetically labeled Hep-G2cells via endocytosis were taken as the objective samples,77%±5.57Hep-G2cellscould be captured specifically and7.33%±4.51blood cells were capturednon-specifically. If magnetically labeled Hep-G2cells via immue method were taken asthe objective samples, the capture efficiency of HepG2cells was65.67%±2.89and thecapture efficiency of blood cells was7.1%±0.83. In a word, the designed microfluidicchip composed of micro magnetic structures could be used for the the captuer of cancercells and in situ test successfully, which provided the potential of microfluidic chipsystems in the detection of circulating tumor cells.3. The microfluidic system described above was applied in studying the inhibitoryeffects of natural extracts (Bergapten,Ber) on Hep-G2cells. HepG2cells weresuccessfully cultured in the microchip for over72hours. And the viability percentage of the Hep-G2cells was higher than90%with staining of trypan-blue. The Hep-G2cellswere exposed to the Ber solutions at different concentrations for12h,24h and48h,respectively. The effect of the drug on cell proliferation was measured by CFSE labeledcell viability measurements using a microplate-reader. Results showed that Ber couldinhibit the activity of Hep-G2cells, which depended on the dose of Ber and action time.Compared with the blank control group (0μmol L-1), the cell density turned to besmaller and the intercellular space turned to be larger along with the increasing of Berconcentration in the experimental groups. Results resvcratrol inhibited the proliferationof HepG2cells with IC50value of47.5μmol/L at48h. The unique advantages ofmicrofluidic array were increasingly being developed and employed as a simple drugscreening tool.