Dual-Multivalent-Aptamer-Conjugated Nanoprobes for Superefficient Discerning of Single Circulating Tumor Cells in a Microfluidic Chip with Inductively Coupled Plasma Mass Spectrometry Detection

Abstract

The efficient recognition of circulating tumor cells (CTCs) with an aptamer probe confers numerous benefits; however, the stability and binding affinity of aptamers are significantly hampered in real biological sample matrices. Inspired by the efficient preying mechanism by multiplex tubing feet and endoskeletons of sea urchins, we engineered a superefficient biomimetic single-CTC recognition platform by conjugating dual-multivalent-aptamers (DMAs) Sgc8 and SYL3C onto AuNPs to form a sea urchin-like nanoprobe (sea urchin-DMA-AuNPs). Aptamers Sgc8 and SYL3C selectively bind with the biomarker proteins PTK7 and EpCAM expressed on the surface of CTCs. CTCs were captured with 100% efficiency, followed by sorting on a specially designed multifunctional microfluidic configuration, integrating a single-CTC separation unit and a hydrodynamic filtrating purification unit. After sorting, background-free analysis of biomarker proteins in single CTCs was undertaken with inductively coupled plasma mass spectrometry by measuring the amount of 197Au isotope in sea urchin-DMA-AuNPs. With respect to a single-aptamer nanoprobe/-interface, the dual-aptamer nanoprobe improves the binding efficiency by more than 200% (K d < 0.35 nM). The microchip facilitates the recognition of single CTCs with a sorting separation rate of 93.6% at a flow rate of 60 μL min–1, and it exhibits 73.8 ± 5.0% measurement efficiency for single CTCs. The present strategy ensures the manipulation and detection of a single CTC in 100 μL of whole blood within 1 h.

Circulating tumor cell isolation for cancer diagnosis and prognosis

“… 119 After microfluidic isolation, the CTC protein can also be recognized by using an aptamer probe based on inductively coupled plasma mass spectrometry (ICP-MS), which exhibits a 73% measurement efficiency for single CTCs. 132 …”

What the Microscale Systems “See” In Biological Assemblies: Cells and Viruses?

“…Therefore, it is necessary to study the cytotoxicity mechanism and cellular distribution of FePt NPs. The microchip–MS system is considered an efficient platform for the cell assay. , A droplet-splitting microchip integrated with time-resolved inductively coupled plasma MS (ICPMS) was applied to quantify Fe and Pt released from FePt-Cys NPs in single HepG2 cells . The developed chip was composed of droplet generation, cell lysis, and droplet-splitting units.…”

Multifunctional Gelatin-Nanoparticle-Modified Chip for Enhanced Capture and Non-Destructive Release of Circulating Tumor Cells

“…The traditional physical methods based on cellular size, electric properties, density, and deformability may cause cell loss and low purity. In order to solve these problems, researchers have developed diverse mechanisms of CTC enrichment, such as immunomagnetic separation [ 15 , 16 ], microfluidic chips [ 17 , 18 , 19 , 20 ], and micro-filter devices [ 21 , 22 ]. Although these methods have their own advantages, the complicated experimental operations and the long analytical time limit their further application.…”