Application of Triarylboron Substituted with Cyclic Arginine–Glycine–Aspartic Acid Motifs as a Multivalent Two-Photon Fluorescent Probe for Tumor Imaging in Vivo

Detection of cancer in its early stages is difficult, and this is a major issue that impairs the timely diagnosis and treatment of tumors. Integrin αVβ3 is expressed on tumoral endothelial cells, as well as other tumor cells. By functionalizing the triarylboron (TAB) compound with multiple cyclic arginine–glycine–aspartic acid (cRGD) motifs, which specifically bind to integrin αVβ3, a multivalent two-photon fluorescent probe TAB-3-cRGD was designed and chemically synthesized. Through cell imaging experiments, we showed that TAB-3-cRGD can selectively bind to integrin αVβ3 on the cell surface and can effectively distinguish normal cells from tumor cells overexpressing integrin αVβ3. Using a mouse model, we also showed that TAB-3-cRGD could target the tumor site in vivo, offering a promising tool for cancer detection.