Functional Diagnostic and Therapeutic Nanoconstructs for Efficient Probing of Circulating Tumor Cells

Abstract

The circulation of tumor cells in peripheral blood is mostly recognized as a prerequisite for cancer progression or systemic invasion, and it correlates with the pivotal hallmark of malignancies known as metastasis. Multiple detection schemes for circulating tumor cells (CTCs) have emerged as the most discerning criteria for monitoring the outcome of anticancer therapy. Therefore, there has been a tremendous increase in the use of robust nanostructured platforms for observation of these mobile tumor cells through various simultaneous diagnosis and treatment regimens developed from conventional techniques. This review seeks to give detailed information about the nature of CTCs as well as techniques for exploiting specific biomarkers to help monitor cancer via detection, capturing, and analysis of unstable tumor cells. We will further discuss nanobased diagnostic interventions and novel platforms which have recently been developed from versatile nanomaterials such as polymer nanocomposites, metal organic frameworks, bioderived nanomaterials and other physically responsive particles with desirable intrinsic and external properties. Herein, we will also include in vivo nanotheranostic platforms which have received a lot of attention because of their enormous clinical potential. In all, this review sums up the general potential of key promising nanoinspired systems as well as other advanced strategies under research and those in clinical use.

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

“…For example, CTCs are commonly described to express epithelial markers like EpCAM and cytokeratins (CKs), and to be nucleated (identified by staining with a nuclear dye such as DAPI, 4′, 6-diamidino-2-phenylindole). Moreover, CTCs do not express cell surface marker CD45 which is specific for white blood cells [43][44][45][46]. In summary, it can be declared that positive results in CTC specific detection can be obtained by using a variety of epithelial-, mesenchymal-, and stem cell markers.…”

“…Additionally, in order to determine and eliminate debatable cells 'negative markers' could be used for CTC detection. These markers include for example platelet marker CD61, CD45 and apoptosis marker M30 [43][44][45][46]. Some of these key biomarkers are illustrated in Figure 2.…”

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

“…The use of HER2, vimentin, ALDH1, and CD44 is also common for CTC-specific detection. [39][40][41][42] To sum up, it can be stated that a variety of epithelial-, mesenchymal-, and stem-cell markers can be applied for positive results in CTC-specific detection. Some examples of these key biomarkers are listed in Table 1.…”

“…These markers include, eg, white blood-cell marker CD45, platelet marker CD61, and apoptosis marker M30. [39][40][41][42]…”

Recent Development of Nanomaterials-Based Cytosensors for the Detection of Circulating Tumor Cells

“…Furthermore, aptamer-based cytosensing approaches for the capture and detection of CTCs have been covered in several review papers [38,50,52,53]. However, to the best of our knowledge, there are few reports focused on nanomaterials-based cytosensors for CTCs detection including both immunosensors and aptasensors [59,60]. In this review, we aim to give a comprehensive review about various nanoplatforms and highlight the different roles of nanomaterials in cytosensors.…”