Theranostic Polyaminocarboxylate-Cyanine-Transferrin Conjugate for Anti-Cancer Therapy and Near IR Optical Imaging

Abstract

Iron depletion using iron chelating agents has been recognized as a promising anti-tumor therapeutic strategy. We herein report a novel theranostic agent for targeted iron chelation cancer therapy and near IR optical imaging. The theranostic agent was prepared via incorporation of a polyaminocarboxylated-based cytotoxic chelating agent (N-NE3TA) and a near IR fluorescent cyanine dye (Cy5.5) into a tumor targeting transferrin. The cytotoxic chelating agent was conjugated to transferrin (Tf), and the corresponding NE3TA-Tf conjugate was characterized and evaluated for anti-proliferative activity in HeLa, HT29, and PC3 cancer cells with elevated expression of transferrin receptor (TfR). The NE3TA-Tf conjugate displayed significant inhibitory activity against cancer cells (HeLa, HT29, and PC3). The near IR dye Cy5.5 was loaded into the NE3TA-Tf platform, and the cytotoxic and fluorescent transferrin conjugate ( N-NE3TA-Tf-Cy5.5) was microscopically shown to enter the TfR over-expressing cancer cells. The theranostic conjugate ( N-NE3TA-Tf-Cy5.5) has a potential application for dual use in targeted iron chelation cancer therapy and near IR fluorescence (NIRF) imaging.

Graphical abstract