Functionalized Carbon Nanostructures in Cancer Diagnosis and Therapy

Cancer is the most prominent life-threatening disease that affects approximately 60 organs and is distinguished by the unlimited growth of cells. Early diagnosis and treatment can reduce the mortality rate and treatment cost. Nanostructures (NSs) are widely used in various biomedical applications owing to their distinctive properties like small size and high surface area, increased diffusion and solubility, enhanced reactivity and colloidal stability, easy surface functionalization, and targeting capability. NSs made from metal, metalloids, metal oxide, and carbon are mainly used for cancer management due to their magnificent electrical, mechanical, and optical properties. Among the various NSs, carbon nanostructures (CNSs) such as carbon dots (CDs), carbon nano-onions (CNOs), carbon nanohorns (CNHs), carbon nanotubes (CNTs), fullerenes, graphene, and nanodiamonds (NDs) are promising alternatives for cancer management due to their distinctive optical properties, high binding affinity, and large surface area. Further, the surface functionalization of CNSs with different organic or inorganic materials, and multiple contrast agents make them a probe for double/triple or multimode imaging, Furthermore, the therapeutic efficiency of drugs and simultaneous elimination of associated adverse effects can be decreased by surface attachment of different targeting ligands like folic acid, ligands with robust affinity against an overexpressed receptor in cancer, and specific antibodies. This chapter briefly focuses on the details of the various functionalized CNSs used for cancer detection and treatment. Further, the application of various functionalized CNSs in cancer diagnosis and therapy is discussed. Additionally, various challenges and future perspectives of CNSs are discussed for their safer use and wider application.