Application of nanomaterials in early diagnosis of cancer

Early diagnosis of cancer is beneficial to improve the outcomes of clinical treatment and reduce cancer mortality. Nanomaterials (NMs) have exhibited significant advantages in early diagnosis of cancer. Due to the integrated structure and features of NMs, they can easily penetrate the tissue for the in vivo diagnosis and identify cancer cells after specific conjugation with unique markers expressed on or within the cancer cells based on the biological imaging such as Raman imaging, fluorescence imaging, and near-infrared imaging, whereas the NMs for the in vitro diagnosis can detect signals based on the electrochemical reactions, immune reactions, and colorimetric reactions, analyzing cancer markers such as small molecules, proteins (or enzymes), genetic materials or cells in the blood, urine, and saliva. NMs with novel physical properties facilitate the detection and imaging of low concentrations and enable the sensitive capture of small cancer biomarkers, achieving early cancer detection. However, a comprehensive summary of such NMs has not been reported. This article provides a detailed review of the types and diagnostic mechanisms of NMs for early cancer diagnosis, emphasizing new perspectives on the use of the in vivo and the in vitro NMs for early cancer diagnosis and proposing the development prospects of such NMs. This will provide new ideas and scientific references for the application of NMs in early cancer diagnosis.