Nanotechnology in Cancer Diagnostics

Early and precise detection of cancer decreases its fatality rate to a great extent. Conventionally, diverse screening methods are there to detect any abnormality or phenotypical changes in tissues or cell masses. For instance, MRI for sensing cancerous growth in CNS; CT scan for diagnosing lung cancer, colorectal cancer, and others with an accuracy of 93.5%. Chest X-ray is performed for symptomatic lung cancer with 77–80% sensitivity. For lung, colon, stomach, or rectum cancer, endoscopy is carried out. However, all these traditional methods have their limitations such as prostate cancer is very much difficult to be diagnosed by CT scan technology because of its interior soft tissue characterization. Incorporating nanotechnology in this discipline enhances their diagnostic efficiency. It also provides the opportunity for therapeutic intervention. Consequently, diverse NPs have been evolved for imaging, drug delivery, biosensing, and photothermal therapy such as MNPs, AuNPs, QDs, CNPs, SNPs, polymer-based NPs (liposome, dendrimers, core-shell NPs), and others. Due to unique optical and electronic properties, AuNPs are exploited as biosensors, contrast agents, and therapeutics. It is employed as contrasting agent in MRI, CT scan, PFTI, XRFI, and other imaging modalities. QDs are also applied in diagnostic methods for sensing malignancy in tissues of lung, breast, and other organs. Correspondingly, polymeric NPs, CNPs, SNPs are also incorporated for better tomography. However, retention of these NPs inside cells for longer time can lead to cytotoxicity, ROS generation, fibrosis, allergy, or organ failure. Therapeutic applications of these NPs can also develop toxic effects in biological system. So, a regulated and balanced nanointervention in cancer diagnosis is highly desirable for early and precise detection besides surmounting the limitations of conventional diagnostics as well as avoiding nanotoxicology concern.