Synthesis of a Novel IR-822-Met near-infrared probe for in vivo tumor diagnosis

Objective Methionine is a valid target for the treatment of cancer and to achieve in vivo imaging and early diagnosis of tumors, we have synthesized near-infrared (NIR) fluorochrome IR-822-labeled methionine (IR-822-Met). Results NIR fluorescent dye IR-822 was conjugated with methionine through its amide bond. It had low toxicity to normal cell/tissues. In vitro and in vivo studies demonstrated its high targeting capability to tumors. The results support the potential of using ligand-modified methionine probe for tumor diagnosis and targeted therapy. The probe also exhibited good photostability, and excellent cell membrane permeability. Conclusion IR-822-Met is a promising imaging agent for tumor diagnosis, especially in their early stage.