Integrin (αvβ3) Targeted RGD Peptide Based Probe for Cancer Optical Imaging.

Integrins have an important impact on the regulation of normal and tumor cell migration and survival, especially the integrin αvβ3 and its role in angiogenesis and tumor metastasis. Owing to the role of integrins, non-invasive imaging of αvβ3 expression in diseased tissue will be of great benefit in directing adjuvant therapy for cancer patients. To this end, RGD peptide based probes for optical imaging have emerged as a real-time, sensitive, and noninvasive approach for visualization, localization, and measurement of cancer in vivo. With the advantages of optical imaging such as sensitivity, cost effectiveness, and non-invasion, the past decades have witnessed the rapid development of integrin- targeted optical probes and its wide applications in cancer research. In this review, we present and introduce numerous approaches by the term "RGD motif based optical imaging probes" with respect to their probe design strategies and applications. Additionally, a variety of labels such as QDs, UCLs and near-infrared fluorochrome used in these optical imaging probes are also discussed.