Emerging roles of carbon nanotubes in cancer therapy, diagnosis and targeted drug delivery: Current insights and toxicity considerations

Carbon nanotubes (CNTs) have become novel carriers for both small and large medicinal compounds. Their usefulness in biomedical applications can be increased by functionalizing their surfaces with particular chemical groups to alter their biological and physical characteristics. CNTs are useful tools in the therapy of cancer because of their vast surface area, movable physical dimensions, and capacity to carry a variety of therapeutic chemicals. Notably, by transforming light energy into heat, they are used in photothermal treatment to kill cancer cells. Site-specific medication delivery has become a growing focus of nanotechnology, and carbon nanotubes (CNTs) have drawn a lot of interest for their ability to transport biomolecules in cancer treatment and diagnosis. Pure CNTs, however, have drawbacks such as poor solubility, which restricts their use in medicine. One important tactic to increase CNTs' solubility and biocompatibility in aqueous conditions and make them more appropriate for therapeutic usage has been functionalization (f-CNTs). The promise of carbon nanotubes (CNTs) as sophisticated drug delivery systems is highlighted in this review, with a focus on their use in targeted therapies and combination techniques such as photothermal (PTT) and photodynamic therapies (PDT), especially in the treatment of cancer. CNTs enable synergistic PTT and PDT for cancer cell death. NIR light triggers PTT heat (>50°C), causing protein denaturation, membrane rupture, and necrosis. PDT generates ROS (singlet oxygen), inducing oxidative damage, caspase activation, and apoptosis. Combined therapy achieves >90% tumor ablation while sparing healthy tissue.