Ultrasensitive Detection of Cancer Biomarkers in the Clinic by Use of a Nanostructured Microfluidic Array

Abstract

Multiplexed biomarker protein detection holds unrealized promise for clinical cancer diagnostics due to lack of suitable measurement devices and lack of rigorously validated protein panels.Here we report an ultrasensitive electrochemical microfluidic array optimized to measure a four-protein panel of biomarker proteins, and we validate the protein panel for accurate oral cancer diagnostics. Unprecedented ultralow detection into the 5−50 fg•mL −1 range was achieved for simultaneous measurement of proteins interleukin 6 (IL-6), IL-8, vascular endothelial growth factor (VEGF), and VEGF-C in diluted serum. The immunoarray achieves high sensitivity in 50 min assays by using off-line protein capture by magnetic beads carrying 400 000 enzyme labels and ∼100 000 antibodies. After capture of the proteins and washing to inhibit nonspecific binding, the beads are magnetically separated and injected into the array for selective capture by antibodies on eight nanostructured sensors. Good correlations with enzyme-linked immunosorbent assays (ELISA) for protein determinations in conditioned cancer cell media confirmed the accuracy of this approach. Normalized means of the four protein levels in 78 oral cancer patient serum samples and 49 controls gave clinical sensitivity of 89% and specificity of 98% for oral cancer detection, demonstrating high diagnostic utility. The low-cost, easily fabricated immunoarray provides a rapid serum test for diagnosis and personalized therapy of oral cancer. The device is readily adaptable to clinical diagnostics of other cancers.

3D printed microfluidic devices with integrated valves

“…1 is a critical technology for an extremely broad range of biomedical applications including tissue engineering, 2,3 drug discovery, 4 point-of-care diagnostics and pathogen detection in both developed and developing countries, [5][6][7][8] and cancer screening using approaches such as cell identification, 9 and protein, [10][11][12][13] DNA, 14 and micro-RNA 15,16 biomarkers. Microfluidic device prototyping for proof-of-principle demonstration typically utilizes hot embossed or injection molded plastics 1,17 or polydimethylsiloxane (PDMS).…”

Detection of Proteins Using Nano Magnetic Particle Accumulation-Based Signal Amplification

“…Common approaches to amplifying the signal from magnetic particle-based biosensors are the use of additional magnetic [16] or nonmagnetic particles, such as labels coated with biomolecules to either bind to a target molecule [19] or bind to magnetic beads [18,20]. In a companion paper [21] we introduced an alternative signal amplification method based on magnetic bead accumulation.…”

Microfluidics technology: future prospects for molecular diagnostics

“…The LOD reached a range of 5-50 fg/mL. 65 In clinical applications, enzyme-linked immunosorbent assay (ELISA) is broadly used as a diagnostic tool for its precision, sensitivity, versatility, and quantifiability. Conventional ELISA protocols require multiple steps of adsorption, washing, and incubation of reagents.…”