Gold-stabilized carboxymethyl dextran nanoparticles for image-guided photodynamic therapy of cancer.

Photodynamic therapy (PDT) has been extensively investigated to treat cancer since it induces cell death through the activation of photosensitizers by light. However, its success has been hampered by the insufficient selectivity of photosensitizers to tumor tissues. In an attempt to increase the therapeutic efficacy of PDT by targeting the photosensitizer specifically to the tumor site, we prepared chlorin e6 (Ce6)-loaded gold-stabilized carboxymethyl dextran nanoparticles (Ce6-GS-CNPs). Ce6-GS-CNPs possessed highly stable nanostructures and no significant change was observed in their particle size in the presence of serum for 6 days. When Ce6-GS-CNPs were intravenously injected into tumor-bearing mice, they exhibited prolonged circulation in the body and gradually accumulated in the tumor tissue. Under laser irradiation of the tumor site which could be recognized by the near-infrared fluorescence imaging system, Ce6-GS-CNPs effectively suppressed tumor growth. Overall, Ce6-GS-CNPs might have potential as nanomedicine for image-guided photodynamic cancer therapy.