Heparin immobilized gold nanoparticles for targeted detection and apoptotic death of metastatic cancer cells

In the present study, heparin immobilized, multifunctional gold nanoparticles (AuNPs) were developed as a new class of theragnostic nanomaterials for metastatic cancer cell imaging and apoptosis. AuNPs were surface modified with fluorescent dye labeled heparin molecules to detect a metastatic stage of cancer cells that over-express heparin-degrading enzymes. The heparin immobilized AuNPs exhibited enhanced fluorescence signals by specific cleavage of heparin molecules from the surface of AuNPs by heparinase or heparanase secreted from metastatic cancer cells. In addition, heparin immobilized AuNPs that were additionally tethered with RGD peptides on the surface demonstrated highly specific apoptotic activities for selective cancer cells over-expressing RGD receptors on the membrane, revealing that internalized heparin within cells clearly triggered an apoptotic event. These results suggest that heparin immobilized AuNPs can be usefully exploited for optical imaging agents for metastatic tumors as well as therapeutic cancer treatment. (C) 2010 Elsevier Ltd. All rights reserved.