Modular Integrated Chamber Assembled With Cell-replicated Surfaces For Capture Of Circulating Tumor Cells

With the advent of an aging society,cancer has become a more and more serious threat to human beings,which is the main cause of death in China.Circulating tumor cells(CTCs)are rare cancer cells that have detached from primary or metastatic tumors and migrated into the peripheral bloodstream,carrying significant information of cancer progression and metastasis.Therefore,the isolation and characterization of CTCs has been regarded as a liquid biopsy technology for cancer diagnosis,genotyping,and prognosis.However,the isolation of CTCs is particularly challenging because of the extremely low concentration of CTCs in peripheral blood.For example,a previous study reported about 75%breast cancer patients at cancer stage I and II have merely 1-4 CTCs in 30 m L of blood.Besides,CTC number in late-stage cancer patients ranges from several to hundreds in 1 mL of blood yet surrounding with millions of white blood cells and billons of red blood cells.In this paper,a modular integrated chamber(MIC)is designed to meet the need of treating required volume of blood in different-stages cancer patients.The research work is mainly carried out in the following aspects:(1)The preparation of Cell RePDMS and the modification of Anti-EpCAM.This paper created a well-defined cell-replicated topological structure of the alcohol-dehydrated cells on the PDMS(CellRePDMS)surface via soft lithography.Then,CellRePDMS surfaces was further modified with Anti-EpCAM via biotin-avidin interaction.The experimental results showed that template cells-replicated feature was successfully embedded into the surface of the CellRePDMS,and the characterization results revealed that Anti-EpCAM was not only bioactive but also averagely distributed over the surface of CellRePDMS.(2)The capture performance of CTCs with the Cell RePDMS/Anti-EpCAM.The CellRePDMS/Anti-EpCAM surface had a capture efficiency up to 90%for anti-EpCAM-positive cancer cells,but the adhesion rate of PBMC cells was very low,only200 cells/cm~2 because of the dual recognition motifs ensemble of molecular recognition and topographic feature.Moreover,Cell RePDMS/Anti-EpCAM surface could capture not only EpCAM-positive cancer cells but also EpCAM-negative cancer cells,despite a little low capture yield for EpCAM negative cancer cells.It also had a high capture efficiency(~85%)and high capture purity(92%)from CTC artificial blood samples.(3)The preparation of modular integrated chamber and its capture performance of CTCs from CTC artificial blood samples.This modular integrated chamber displayed a high capture efficiency(~80%)and high capture purity(~90%)within 1 h in both cancer middle-early stage and late stage-simulating blood samples.This result could be compared with the microfluidic technology which had a higher CTC-capture yield and selectivity,and overcomed the time-consuming shortcoming when capture CTCs from a large volume.In summary,the MIC assembled with Cell RePDMS/Anti-EpCAM enable fast,efficient and highly-purified capture CTCs from not only small but also large volumes of blood for the liquid biopsy of cancer patients at different cancer stages.This economy and facile system would provide new clues for developing new CTC capture methods and also open up opportunities in designing next-generation devices for the CTC detection.