In Vivo Optical Imaging Of Head And Neck Squamous Cell Carcinoma Using Arginine-glycine-aspartic Acid Peptide

Objective: To observe the in situ imaging and body distribution of arginine-glycine-aspartic acid peptide conjugated near-infrared fluorescentquantum dots on head and neck squamous cell carcinoma (HNSCC).Methods: In this study, we conjugated RGD which could speciallybinds to integrin αvβ3with QD800to generate QD800-RGD, and used itvia intravenous injection as a probe to image tumors in nude mice bearingHNSCC at six different time points. Twelve hours later, the mice weresacrificed,the tumors and ten major organs were isolated for ex vivoanalysis to detect QD800-RGD probe in the location in the tumor tissueand the body distribution.Results：The results showed that QD800-RGD was specificallytargeted to integrin αvβ3in vivo, producing clear tumor fluorescenceimages after the intravenous injection. The tumor-to-background ratio andsize of tumor image were highest within6hours of the injection anddeclined significantly at9hours after the injection, but there was still aclearly visible tumor image at12hours. The greatest amount of QD800-RGD was found in liver and spleen, followed by tumor and lung,and a weak fluorescence signal was seen in tibia. No detectable signal ofQD800-RGD was found in brain, heart, kidney, testis, stomach, orintestine.Conclusion:Our study demonstrated that it is possible to useintravenously injected QD800-RGD to specially target integrin αvβ3expressed on tumor neovasculature， thus producing clear tumorfluorescence images. It has promising prospects in the occurrence anddevelopment study，diagnosis and individual treatment of HNSCC.