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

Abstract

Circulating tumor cells (CTCs) are disseminated cancer cells. The occurrence and circulation of CTCs seem key for metastasis, still the major cause of cancer-associated deaths. As such, CTCs are investigated as predictive biomarkers. However, due to their rarity and heterogeneous biology, CTCs’ practical use has not made it into the clinical routine. Clearly, methods for the effective isolation and reliable detection of CTCs are urgently needed. With the development of nanotechnology, various nanosystems for CTC isolation and enrichment and CTC-targeted cancer therapy have been designed. Here, we summarize the relationship between CTCs and tumor metastasis, and describe CTCs’ unique properties hampering their effective enrichment. We comment on nanotechnology-based systems for CTC isolation and recent achievements in microfluidics and lab-on-a-chip technologies. We discuss recent advances in CTC-targeted cancer therapy exploiting the unique properties of nanomaterials. We conclude by introducing developments in CTC-directed nanosystems and other advanced technologies currently in (pre)clinical research.

Keywords:

• liquid biopsy
• cancer biomarker
• metastasis
• nanomedicine
• nanotherapy
• therapy resistance

Acknowledgments

This work was supported by grants from the Research Center for Natural and Medical Sciences ([Naturwissenschaftlich-medizinisches Forschungszentrum]; NMFZ), Impulse Fund Rhineland Palatinate, Brigitte and Dr Konstanze Wegener Foundation, German Research Foundation ([Deutsche Forschungsgemeinschaft]; DFG) and NanoTransMed, which is co-funded by the European Regional Development Fund (ERDF) in the framework of the Interreg V Upper Rhine program, the Swiss Confederation, and the Swiss cantons of Aargau, Basel-Landschaft, and Basel-Stadt.

Author contributions

All authors contributed toward data analysis, drafting and critically revising the paper, gave final approval of the version

Disclosure

The authors report no conflicts of interest in this work.