Dual-source powered nanomotors coupled with dual-targeting ligands for efficient capture and detection of CTCs in whole blood and in vivo tumor imaging

Design and Application of Microfluidic Capture Device for Physical-Magnetic Isolation of MCF-7 Circulating Tumor Cells

Circulating tumor cells (CTCs) are a type of cancer cell that spreads from the main tumor to the bloodstream, and they are often the most important among the various entities that can be isolated from the blood. For the diagnosis of cancer, conventional biopsies are often invasive and unreliable, whereas a liquid biopsy, which isolates the affected item from blood or lymph fluid, is a less invasive and effective diagnostic technique. Microfluidic technologies offer a suitable channel for conducting liquid biopsies, and this technology is utilized to extract CTCs in a microfluidic chip by physical and bio-affinity-based techniques. This effort uses functionalized magnetic nanoparticles (MNPs) in a unique microfluidic chip to collect CTCs using a hybrid (physical and bio-affinity-based/guided magnetic) capturing approach with a high capture rate. Accordingly, folic acid-functionalized Fe3O4 nanoparticles have been used to capture MCF-7 (breast cancer) CTCs with capture efficiencies reaching up to 95% at a 10 µL/min flow rate. Moreover, studies have been conducted to support this claim, including simulation and biomimetic investigations.

Carbon dot-based fluorescent probe for early diagnosis of pheochromocytoma through identification of circulating tumor cells

Pheochromocytoma (PCC), as a rare neuroendocrine tumor, is often missed or misdiagnosed because of its atypical clinical manifestations. To realize the early accurate diagnosis of PCC, we have selected circulating tumor cells (CTCs) with more complete biological information as biomarkers and developed a simple and novel fluorescence cytosensor. Octreotide-2,2',2'',2'''- (1,4,7,10 -tetraazacyclododecane-1,4,7,10-tetrayl) tetraacetic acid (DOTA) modified magnetic Fe3O4 and signal amplification CDs@SiO2 nanospheres are prepared to capture and detect PCC-CTCs from peripheral blood via binding to the somatostatin receptor SSTR2 overexpressed on the surface of PCC cells. During the detection process, the target cells were separated and enriched by magnetic capture probes (Fe3O4-DOTA), and then signal probes (CDs@SiO2-DOTA) could also specifically bound to target cells to form the sandwich-like structure for fluorescence signal output. The proposed fluorescence cytosensor has revealed good sensitivity and selectivity for quantitative analysis of PCC-CTCs in the concentration of 5-1000 cells mL-1 with a LOD of 2 cells mL-1. More importantly, designed fluorescence cytosensor has shown good reliability and stability in complex serum samples. This strategy provides a new way for detection of PCC-CTCs.

Nano/Micromotors for Cancer Diagnosis and Therapy: Innovative Designs to Improve Biocompatibility

Nano/micromotors are artificial robots at the nano/microscale that are capable of transforming energy into mechanical movement. In cancer diagnosis or therapy, such "tiny robots" show great promise for targeted drug delivery, cell removal/killing, and even related biomarker sensing. Yet biocompatibility is still the most critical challenge that restricts such techniques from transitioning from the laboratory to clinical applications. In this review, we emphasize the biocompatibility aspect of nano/micromotors to show the great efforts made by researchers to promote their clinical application, mainly including non-toxic fuel propulsion (inorganic catalysts, enzyme, etc.), bio-hybrid designs, ultrasound propulsion, light-triggered propulsion, magnetic propulsion, dual propulsion, and, in particular, the cooperative swarm-based strategy for increasing therapeutic effects. Future challenges in translating nano/micromotors into real applications and the potential directions for increasing biocompatibility are also described.