研究了偶联环状精氨酸-甘氨酸-天冬氨酸-D-苯丙氨酸-赖氨酸[c(RGDfK)]肽段的CdSe/ZnS量子点(QDRGD)对喉癌血管靶向成像。利用羧基与氨基反应将c(RGDfK)肽段与QD偶联;采用荧光分光光度计对QD-RGD在RMPI1640培养基和小鼠血清溶液中的光谱稳定性进行了检测;利用荧光显微镜检测QD-RGD对Hep-2细胞和MCF-7细胞上整合素αvβ3的靶向性;最后将QD-RGD尾静脉注射到小鼠体内,检测了其对皮脊翼视窗中喉癌血管的靶向性。结果表明QD-RGD的发射光谱在RMPI1640培养基4h内没有明显变化,在小鼠血清中24h内发射光谱的荧光强度仅下降了20%;对细胞荧光成像表明QD-RGD能特异性与细胞表面的整合素αvβ3结合;血管成像表明QD-RGD在注射2h后聚集在喉癌局部血管,24h后QD-RGD从血管中移除。该研究表明QD-RGD能用于活体喉癌肿瘤血管靶向成像,这为喉癌的靶向诊断和靶向治疗研究提供了参考。
The targeted imaging of quantum dot (QD) conjugated cyclo (Arg-Gly-Asp-D-Phe-Lys) peptides [c (RGDfK), QD-RGD] for laryngeal cancer blood vessel in vivo is studied. QD is conjugated with c(RGDfK) peptides by the reaction of carboxyl and amino groups. The spectra stabilities of QD-RGD in RMPI1640 and mouse serum are measured by fluorescence spectrophotometer. The targeting of QD-RGD to avβ3 on Hep-2 and MCF-7 cells is studied by fluorescent microscope. Finally, the targeting of QD-RGD to laryngeal cancer vascular in dorsal skin fold window chamber by tail intravenous injection is investigated. The result shows that the spectra stability of QD-RGD in RPMI1640 does not obviously change in 4 hours. The fluorescence intensity of QD-RGD in mouse serum in 24 hours only decreases by 20 %. The result of cells fluorescence imaging shows that QD-RGD can specifically bind to integrin a1β1 on cells. The result of vascular imaging shows QD-RGD gathers in cancer blood vessel after injecting for 2 hours, and QD-RGD is removed from cancer blood vessel after 24 hours. The study demonstrates that QD-RGD can be used to targeted image cancer blood vessel in vivo, which offers a reference for studying targeting diagnosis and targeting therapy of laryngocarcinoma in vivo.