The Research Of Circulating Tumor Cells Detection Based On Polymer And Micro-nano Structure

Circulating tumor cells(CTCs)in peripheral blood are important indications of tumor metastasis and recurrence.However,the level of tumor cells in the blood is very low,which is only a few to hundreds of CTCs in 10~9 blood cells and creats great difficulties for the detection of CTCs.Therefore,how to effectively,rapidly and accurately separate and enrich CTCs in complex peripheral blood environment becomes a major problem.At present,the separation of CTCs can be divided into two categories,one is based on the physical properties(size,density,deformability,dielectric properties,etc.);the other is based on biological properties(surface protein expression and invasion capacity).However,it is reported that the presence of various epithelial cell markers such as EpCAM varies with tumor type,And some tumor cells have a similar size with blood cells such as small lung cancer cells,and sometimes do not secrete surface markers,which makes the traditional separation methods cannot effectively separate cancer cells.Thus,we need to found a method to separate CTCs efficiently.In this study,to accurately detect CTCs we set up two new CTCs detection methods based on polymers scaffolds.The idiographic work is as follows:1.We prepared successfully several polydimethylsiloxane(PDMS)microchips with different surface micro-nano structure,which were combined with an electrochemistry workstation,based on UV photolithography technology,magnetron sputtering technology and electrospinning technology,set up a new electrochemical biosensor for quantitative detection of CTCs and studied the influence of different surface structure for the CTCs capture efficiency.The result showed that microchips with columns and nanofibers possessed higher capture efficiency of CTCs compared to the other microchips.The cells captured on the plane substrate are spherical and have no filamentous pseudomonas.However,the cells captured on the substrates with micro-nano structures have filamentous pseudomonas showing the small size effect with the substrates.A linear relationship was found between the peak current and the logarithm of the cell concentration with a certain concentration range of CTCs,which had a correlation coefficient of 0.9992;2.We prepared polyethylene glycol diacrylate(PEGDA)membrane filters with uniform distribution and high porosity,which contained conical shaped holes instead of the ordinary cylindrical holes to increasing the capture efficiency and purity of CTCs,using rotary lithography and UV-Curing technology.The result showed that the microchips intercepted the majority of CTCs showing filamentous pseudomonas,which showed the small size effect with the CTCs.It can be seen that microporous membrane filter can isolate high purity CTCs in large amounts of the non-target cells by immunofluorescence staining results.