Highly efficient circulating tumor cell isolation from whole blood and label-free enumeration using polymer-based microfluidics with an integrated conductivity sensor.
A novel microfluidic device that can selectively and specifically isolate exceedingly small numbers of circulating tumor cells (CTCs) through a monoclonal antibody (mAB) mediated process by sampling large input volumes (>/=1 mL) of whole blood directly in short time periods (<37 min) was demonstrated. The CTCs were concentrated into small volumes (190 nL), and the number of cells captured was read without labeling using an integrated conductivity sensor following release from the capture surface. The microfluidic device contained a series (51) of high-aspect ratio microchannels (35 mum width x 150 mum depth) that were replicated in poly(methyl methacrylate), PMMA, from a metal mold master. The microchannel walls were covalently decorated with mABs directed against breast cancer cells overexpressing the epithelial cell adhesion molecule (EpCAM). This microfluidic device could accept inputs of whole blood, and its CTC capture efficiency was made highly quantitative (>97%) by designing capture channels with the appropriate widths and heights. The isolated CTCs were readily released from the mAB capturing surface using trypsin. The released CTCs were then enumerated on-device using a novel, label-free solution conductivity route capable of detecting single tumor cells traveling through the detection electrodes. The conductivity readout provided near 100% detection efficiency and exquisite specificity for CTCs due to scaling factors and the nonoptimal electrical properties of potential interferences (erythrocytes or leukocytes). The simplicity in manufacturing the device and its ease of operation make it attractive for clinical applications requiring one-time use operation.
Department of Chemistry, Center for BioModular Multi-scale Systems, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
André A
AA
Adams
Paul I
PI
Okagbare
Juan
J
Feng
Matuesz L
ML
Hupert
Don
D
Patterson
Jost
J
Göttert
Robin L
RL
McCarley
Dimitris
D
Nikitopoulos
Michael C
MC
Murphy
Steven A
SA
Soper
D000911:Antibodies, Monoclonal / Q000276:immunology; D001943:Breast Neoplasms / Q000097:blood / Q000175:diagnosis / Q000473:pathology; D015815:Cell Adhesion Molecules / Q000378:metabolism; D045744:Cell Line, Tumor; D002469:Cell Separation / Q000379:methods*; D004553:Electric Conductivity; D004566:Electrodes; D006801:Humans; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D009369:Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D009360:Neoplastic Cells, Circulating / Q000276:immunology / Q000473:pathology; D019904:Polymethyl Methacrylate / Q000737:chemistry
D000911:Antibodies, Monoclonal; D015815:Cell Adhesion Molecules; D019904:Polymethyl Methacrylate