Balancing the Risks and Rewards of Carbon Nanotubes in Cancer Applications

Carbon nanotubes (CNTs), which possess their characteristic structural, electrical, and chemical properties, have become flexible nanomaterials in the theranostics of cancer. They can deliver drugs precisely to their intended target due to their high surface area, tunable surface chemistry, and biological intactness through their ability to cross biological barriers and enhance imaging, as well as enabling new forms of treatment, including photothermal therapy and photodynamic therapy. The clinical efficacy of these light-based modalities is, however, limited because the shallow penetration of the light in the near-infrared (NIR) light can diminish the efficacy of treatment on tumours that are deep-seated. The physicochemical properties that predispose CNTs to be useful in treating the human body also provoke valid questions about the safety of this approach in the long-term, especially concerning carcinogenic effects. This review has critically discussed the dual nature of CNTs in oncology, synthesizing the current developments in the therapeutic applications of CNTs, and describes mechanistic insights about their toxicity. CNTs are used to enhance cancer therapy in terms of their application as drug carriers, radiosensitizers, and immune modulators, and comment on their diagnostic application in multimodal imaging. The CNT/PEI/durvalumab nanoagent systems are among them, and they are preclinical studies that have been carried out primarily on animal models. On the other hand, this review evaluates the increasing evidence that links CNT exposure to oxidative stress, mitochondrial malfunctioning, inflammation, epithelial-mesenchymal transition (EMT), and endothelial leakiness pathways that have been implicated in tumorigenesis and metastasis. The review outlines the significance of standardization of functionalization procedures, strict toxicological testing, and the long-term biocompatibility by comparison of therapeutic benefits and biological risks. These risks and benefits have to be weighed to provide a way of balancing the safety of CNT-based nanotechnologies to leap clinical oncology using the resulting experimental models to guide researchers, clinicians, and regulatory officials.