| Circulating tumor cells(CTCs)are tumor cells that shed from the primary tumor or metastases into the blood circulation of the peripheral blood.CTCs are present in the blood of early cancer patients,and the number and type are closely related to the occurrence and development of cancer.At present,the capture of CTC mainly utilizes the interaction between antigen and antibody.The main reason for the poor effect is that there is a layer of glycocalyx with a thickness of about 500 nm outside the antigen,which greatly hinders the binding of antigen and antibody.This paper simulates the strong interaction between the tannic acid coating on the surface of vascular endothelial cells and glycocalyx on the cancer cell membrane,and mediates the mechanism of micro-metastasis of cancer cell rolling,further adhesion and capture.This new method for the flow capture of CTCs with tannic acid coating is the fastest chemically label-free dynamic capture technique that differs from conventional capture.By constructing a new detachable parallel plate flow chamber that can satisfy the high-speed flow of the sample liquid,the tannic acid is used to modify the surface of the substrate,and the flow is circulated at a high flow rate to increase the contact chance of the CTC with the substrate,and the cancer cells in the flow can roll off.And in a short time,it interacts with the surface of the substrate and then enters the state of rolling and adhering.It is verified that the material can not only capture the cancer cells in a dynamic process,but also effectively exclude the background white blood cells.In clinical trials,CTCs can be detected not only in the blood of 13 advanced patients,but also in CTC cell clusters.This paper mainly carried out the following three work items:(1)Through the layer-by-layer assembly method,a 7-layer coating of tannic acid was successfully obtained on the glass substrate;the parallel plate flow chamber which can satisfy the liquid circulation was successfully constructed by using the plexiglass plate and the PDMS gasket,and simulated by simulation.The distribution of wall shear force in the flow channel was analyzed,and the reasonable area of dynamic capture detection was verified as the central region by actual cell adhesion experiments.The TA concentration was 3.2 mg/m L and the Fe3+ concentration was 0.8 mg/m L by condition optimization.The modified 7-layer TA coating is more susceptible to the flow capture of cancer cells,and the blocking of the hydroxyl groups reduces the capture effect.(2)Three kinds of state-specific detection indexes were established by dynamic microscopy and analysis of cells;from the rolling effect,the adhesion effect,the ability to resist the impact of fast fluids after binding,and whether it has a repulsive effect on white blood cells.It has been shown that TA has excellent cancer cell dynamic capture compared with anti-Ep CAM and E-selectin coatings,and has determined that tannic acid coating has the best cancer cell dynamic capture at high flow rates of 40 m L/h.(3)For the first time,a new strategy for CTCs capture by cancer cells exposed by multiple cycles with a simple and economical planar flow chamber was realized.A simple,high-capacity extracorporeal circulation capture system was successfully constructed with polyphenol surface.The 1.5 mm flow path height and 2 h cycle capture time can achieve the best capture effect,while increasing the flow path length can further enhance the capture effect;in cancer cell simulated blood samples,rare cancer cells at a high flow rate of 40 m L/h The capture yield was 90%,and the background white blood cells were 3/cm2,indicating the high purity of cancer cells.The detection of 1.5 m L blood samples from 13 patients with advanced cancer,the detection rate was 100%,and the number of detection was 2-25/m L,not only can capture a single CTC,but also capture the cell cluster of CTC. |
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