A Novel Microfluidic Chip And Its Application To Capture Circulating Tumor Cells (CTCs)

The circulating tumor cell(CTC)is an important indicator in cancer diagnosis,prognosis,and disease monitoring.However,efficient isolation of CTCs from the peripheral bloodstream has been a persistent challenge due to the rarity of CTCs.Currently,two types of microfluidic methods have been reported for the isolation of CTCs,including size-based and immunoaffinity-based microfluidics.However,the capture efficiency of current methods still needs improvement.In this work,we reported a “ Rhipsalis(Cactaceae)”-like micropillar array-based device with high optical transparency for efficiently capturing cancer cells in three dimensions(XY and Z planes).The PDMS micropillar array was fabricated by soft-lithography and rapid prototyping method.The micropillar array was plated with a thin gold layer through electroless plating.EpCAM antibody was then modified onto the surface of the micropillars through the thiol-oligonucleotide linkers.Hierarchical structures originating from the gold layer are on the surface of the micropillars and the microchannel.The immune-affinity molecules(EpCAM antibodies)could be modified on the gold-coated micropillars and microchannel.Thus,capture of cancer cells could be realized simultaneously on the surface of the micropillars and the microchannel.The device in this study demonstrated a high capture efficiency and release for different kinds of cancer cells,the average capture efficiency of 88% was achieved in PBS and the cancer-cell capture capability with average efficiency of 83.7% in whole blood samples.The high transparency of the whole device allows for direct monitoring captured cells under microscopy,showing its potential applications in CTC studies and clinical diagnosis.Based on the thermo-responsive hydrogels and the combination of microfluidic chip platform,we studied the thermo-responsive hydrogels after joining dopamine,the composite hydrogel had the characteristics of photothermal conversion efficiencies and the change of microstructure.Also,we take advantage of the hydrogel’s thermo-responsive characteristics to implement a series experiment about cells,such as capturing cancer tumor cells,adhesioning cancer cells,density slice layer test of cancer cells and the specific pattern layer test of cancer cells.In this study demonstrated that the composite hydrogel had the characteristics of photothermal conversion efficiencies after joining dopamine,when the same intensity of laser irradiate 170 seconds,with the rising of the concentrations of dopamine,the temperature rise was more obvious,to a maximum of 30oC,the control group temperature was almost no fluctuate.The cancer cell capture capability with average efficiency of 84%.Adhesion effect and the release effect was very obviously,density slice layer and pattern layer test also quickly and ideal,showing its potential applications of the hydrogels.