A photo-triggered conjugation approach for attaching RGD ligands to biodegradable mesoporous silica nanoparticles for the tumor fluorescent imaging.

Fluorescent probes conjugated to peptide or antibody directing groups, which exhibit high signal to background ratios, have been widely used to image tumors and monitor their growth. A photo-triggered cycloaddition reaction between the arginine-glycine-aspartic acid -N-ɛ-acryllysine (RGD-Acrk) peptides and the tetrazole compounds bound to the surface of biodegradable mesoporous silica nanoparticles (bMSN) has been used to construct a fluorescent nanoprobe (bMSN@T2-RGD-Acrk), which showed fluorescent emission at 550 nm and could selectively image the 4T1 cells and breast cancer. This means that the bMSN@T2-RGD-Acrk nanoprobe made by photo-triggered conjugation approach is a promising fluorescent imaging agent for visualizing tumors. Thus, the photo-triggered one-spot reaction can give a stable crosslinker in a biocompatible manner for bioconjugation with nanoparticles and produce a fluorescent group that is suitable for imaging in vivo.