In vitro derby imaging of cancer biomarkers using quantum dots.

Semiconductor quantum dots (QDs), which have broad absorption with narrow emission spectra, are useful for multiplex imaging. Here, fluorescence derby imaging using dual color QDs conjugated by the AS1411 aptamer (targeting nucleolin) and the arginine-glycine-aspartic acid (targeting the integrin alpha(v)beta(3)) in cancer cells is reported. Simultaneous fluorescence imaging of cellular distribution of nucleolin and integrin alpha(v)beta(3) using QDs enables easy monitoring of separate targets in the cancer cells and the normal healthy cells. These results suggest the feasibility of a concurrent visualization of QD-based multiple cancer biomarkers using small molecules such as aptamer or peptide ligands.