Construction And Application Of Circulating Tumor Cells Enrichment/filter Chips Based On Immunoaffinity

circulating tumor cells (CTCs）are cancer cells from the primary lesions invadinginto the circulatory system, which could be an indicator for diagnostics of prognosis ortumor recurrence, revealing the behavior of tumor metastasis and guiding clinicalindividualized treatment, are research focus of the oncology. CTCs detected based onthe immuno-affinity microfluidic chip system have many advantages, such as Highdetection rate, high sensitivity, high specificity, low consumption, simple operation,integrated and automated, which have an important value in the clinical transfer ofcontrol, chemotherapy and radiation effects assessment and prognostic evaluation,transfer of early detection and control the spread of tumor cells, and development oftreatment programs. In this paper, Chip obtaine by Polydimethylsiloxane(PDMS)curing, cleaning, drilling, sealing, modification and interface features，build the CTCsenrichment/filter immunoaffinity chip. By optimization of experimental conditionsparameters, Preliminary evaluation the application of the chip in the blood samples. Theresearch contents and results were as following:1) To improve the probability of target cells and the chip functionalized surface,the micro-dam type, winding type and herringbone chip are designed, using ANSYSsoftware and CFX software analysis to determine the size of the chip and experimentalparameters.2) Determine the way of production and drive. PDMS material molding on thesilicon template or SU-8template to made the chip. The whole PDMS chip treated byplasma sealing, sealing time for the60s, the voltage set to800V, the gas volume flowrate of200ml/min, this method, the chip seal securely, no cracking and leaking. Andexamines the flow of fluid under positive pressure driven and vacuum-driven, choosethe vacuum-driven approach can reduce the loss of target cells in the injection pipe.3) Screening silane reagents for chip modified. Investigatedaminopropyltriethoxysilane(APTES) and3-glycidoxypropyltrimethoxysilane (GPTMS）for PDMS modification effect. Hydrophilicity of samples treated by silylation reagentswas measured by contact angle, screening silane reagent and its concentration. Resultwas verificationed by non-specific cell capture experiments. Then Immobilizedantibody to get preliminary experiments for cell capture studies. The results showed that2%(volume concentration) GPTMS could get a smallest contact angle and non-specific adsorption of cells reduced to5.3%, capture rate of cells was53.96%.4) Five different method to connect antibodies using to build a functional interfaceare tried in this paper. Then the construction method as follows: plasma sealing,2%GPTMS silane treated, PEI grafted and antibody immobilized by glutaraldehyde (GA).Using XPS、ATR-TITR and RMS Characterizating the surfaces, found that this methodmay be connected to antibodies to the "upright" conformation, with the highest antibodyactivity.5) Study the performance of different configurations of the chip. Found that theherringbone chip could using in blood samples for CTCs capture. Conditions optimizedas10ul/min for input and40ul/min for rush.