Targeted Fluorescence Imaging and Biological Effects of Peptide Conjugated Quantum Dots on Pancreatic Cancer Cells

Arginine-glycine-aspartic acid (RGD) peptide sequences exist in a variety of biological extracellular matrices and can specifically bind the cell-surface integrin alphavbeta3, which is overexpressed in cancer cells and plays important roles in tumor growth and invasion. Quantum dots (QDs) have been applied in the field of cell biology and can be physically conjugated to the surface of cancer cells for imaging. In this research, we developed QDs-RGD nanoparticles and investigated its application in pancreatic cancer cell imaging and its influence on the biological behavior of pancreatic cancer cells. The results of flow cytometric analysis showed that the alphavbeta3 receptor was markedly overexpressed on pancreatic cancer cells. In cellular uptake studies, the fluorescence signal of QDs-RGD nanoparticles in pancreatic cancer cells was higher than that of QDs without RGD conjugation, as determined by an inverted fluorescence microscope. Furthermore, the biological behavior of pancreatic cancer cells was affected by QDs-RGD nanoparticles, which inhibited proliferation, migration and invasion and induced G2-phase cell cycle arrest. With integrin alphavbeta3 as a target, QDs-RGD nanoparticles can generate high-quality images of pancreatic cancer cells and have immense potential for use in the targeted diagnosis and therapy of pancreatic cancer.