Micro- and nanotechnology approaches for capturing circulating tumor cells

Abstract

Circulating tumor cells (CTC) are cells that have detached from primary tumors and circulate in the bloodstream where they are carried to other organs, leading to seeding of new tumors and metastases. CTC have been known to exist in the bloodstream for more than a century. With recent progress in the area of micro- and nanotechnology, it has been possible to adopt new approaches in CTC research. Microscale and nanoscale studies can throw some light on the time course of CTC appearance in blood and CTC overexpression profiles for cancer-related markers and galvanize the development of drugs to block metastases. CTC counts could serve as endpoint biomarkers and as prognostic markers for patients with a metastatic disease. This paper reviews some of the recent researches on using micro- and nanotechnology to capture and profile CTC.

Photoacoustic imaging: a potential tool to detect early indicators of metastasis

“…Clinically, labor-intensive and time-consuming laboratory separation techniques, including centrifugation, filtration and magnetic enrichment, followed by immunological assays and microscopic analyses of the captured CTCs, are relied upon to provide information for cancer staging [35]. Detection of CTCs is challenging due to the low number of CTCs present in the background of normal blood cells, and the quantity of CTCs is likely to change with time, reflecting the discontinuous process of cell migration from a tumor into the vasculature.…”

Nanobiotechnology for the capture and manipulation of circulating tumor cells

“…A further motivation for continuous monitoring of the circulation is evident considering the prevalence of CTC: reports have identified as few as 1 CTC per 7.5 mL patient sample 4. On the basis of this estimate, there is a low probability of capturing any CTC in a single blood sample of a few milliliters 14. A device that would allow for screening of the entire circulation would minimize the chance of CTC evading the device.…”

“…Studies have found that unique adhesive properties of the luminal surface of particular organ vasculature are sufficient to explain the habitual homing of certain cancers to specific secondary tissues 6,10–13. Thus, it is evident that the presence of CTC in the circulatory system is a necessary phenomenon in cancer progression, and researchers and physicians have recently begun to recognize the relevance and use of CTC for diagnosis and treatment 14…”

Nanocarbon/elastomer composites : characterization and applications in photo-mechanical actuation.

“…For example, micro-and nano-actuation technologies are being applied in targeted drug delivery systems [19][20][21] , employed as implantable devices to augment failing organs 22 , and used for capture of circulating tumor cells towards early metastatic cancer detection 23 .…”