Circulating Tumor Cells: From Theory to Nanotechnology-Based Detection

Abstract

Cancer stem cells with stem-cell properties are regarded as tumor initiating cells. Sharing stem-cell properties, circulating tumor cells (CTCs) are responsible for the development of metastasis, which significant affects CTC analysis in clinical practice. Due to their extremely low occurrence in blood, however, it is challenging to enumerate and analyze CTCs. Nanotechnology is able to address the problems of insufficient capture efficiency and low purity of CTCs owing to the unique structural and functional properties of nanomaterials, showing strong promise for CTC isolation and detection. In this review, we discuss the role of stem-like CTCs in metastases, provide insight into recent progress in CTC isolation and detection approaches using various nanoplatforms, and highlight the role of nanotechnology in the advancement of CTC research.

<p>Is small smarter? Nanomaterial-based detection and elimination of circulating tumor cells: current knowledge and perspectives</p>

“…The unique properties of NMs can be used to accelerate detection and overcome some limitations in CTC detection. 27 For safe application of NMs as a diagnostic device in cancer therapy, it is necessary to have a detailed understanding of interactions of NPs with cells, tissue, and organisms. 43…”

“…Some unique properties of CTCs can be employed to distinguish CTCs from surrounding normal hematologic cells and also for their enrichment and detection. 27 Current CTC-enrichment methods are based on either physical properties (size, density, deformability, and electrical charge) or biological features (cell-surface protein expression, invasive capacity, and viability). 36 Commonly used isolation methods based on physical properties include density-gradient centrifugation, membrane filtration, and microchip-based capture platforms.…”

“…NMs can also be used as drug-delivery systems for CTCtargeted drugs and cancer treatment. 27 Furthermore, the large surface:volume ratio of NMs endows them with high cellular binding affinity in the complex blood matrix. Manipulation of NMs gives them the ability of multiplexed detection and targeting, which are crucial to approach the heterogeneous problem of CTCs.…”

Nano Meets Micro-Translational Nanotechnology in Medicine: Nano-Based Applications for Early Tumor Detection and Therapy

“…A high level of sensitivity as well as specificity due to the extreme rarity and heterogeneous phenotype of CTCs in the blood system are necessary for an effective capture and accurate identification of CTCs [28]. Current CTC enrichment methods are based on either biological features (cell surface protein expression, invasive capacity, and viability) or physical properties (size, density, deformability and electrical charge) [47].…”

“…Nanostructured substrates demonstrate enhanced local topographic interactions that lead to enhanced cell capture affinity. NMs can also be used as drug delivery systems for CTC-targeted drug delivery and cancer treatment [28]. Moreover, NMs have a large surface-to-volume ratio that endows them with a high cellular binding affinity in the complex blood matrix.…”