| Although considerable efforts have been conducted to diagnose, image, and treat cancer in the past few
decades, existing therapeutic options are still inadequate, as mortality and morbidity rates remain high.
Perhaps the best hope for substantial improvement lies in early detection. Recent advances in
nanotechnology are expected to increase our current understanding of tumor biology, and will allow
nanomaterials to be used for targeting and imaging both in vitro and in vivo experimental models. Owing
to their intrinsic physicochemical characteristics, nanostructures (NSs) are valuable tools that have
received much attention in bioimaging. Consequently, rationally designed NSs have been successfully
employed in cancer imaging for targeting cancer-specific or cancer-associated molecules and pathways.
This review categorizes imaging and targeting approaches according to molecular target and cancer type,
and also highlights some new safe approaches involving membrane-coated nanoparticles (NPs), tumor cell-derived extracellular vesicles, circulating tumor cells, cell-free DNAs, and cancer stem cells (CSCs)
in hope of developing more precise targeting and multifunctional nanotechnology-based imaging probes
in the future |