The spread of cancer,either by metastasis to distant organs or local invasion,is the leading cause of most cancer death [1].For lung cancer diagnosed at an early stage,surgical resection can improve the 5-year survival rate to 60–80%.In this work,we combine the inertial-based microfluidic cell sorter with an integrated membrane filter at the outlet of device,allowing for the size-based,label-free and high-efficient separation and enrichment of CTCs in whole blood from patients with metastatic lung cancer.The isolated and enriched CTCs on the membrane filter could be identify either by immunostaining with specific antibodies or Cytokeratin 19(CK-19)mRNA amplification.The immunofluorescence staining can differentiate the CTCs from peripheral white blood cells(WBC)of similar sizes,and confirm the existence of CTC clusters.The genetic analysis of CK-19 mRNA from captured CTCs in patient samples is performed,and compared with the Cell-Search? system.Hybrid core-shell nanoparticles are becoming a new class of drug nanocarriers due to for their improved therapeutic efficacy and enhanced biocompatibility [2].We present a hollow-structured rigid nanoparticle fabricated by a multi-stage microfluidic chip in one step,to effectively entrap various hydrophilic reagents inside,without complicated synthesis,extensive use of emulsifiers and stabilizers,and laborious purification procedures.The entrapment efficiency of hydrophilic reagents such as calcein,rhodamine B and siRNA inside hollow water core is~90%.In comparison with the combination of free Dox and siRNA,the hollow-structured rigid nanoparticle that co-encapsulates siRNA and doxorubicin(Dox)reveals a significantly enhanced anti-tumor effect for a multi-drug resistant tumor model.