Dual-modality imaging with Tc-99m and fluorescent indocyanine green using surface-modified silica nanoparticles for the image of malignant tumors

我们的目标是利用表面修饰的二氧化硅纳米颗粒，研制用于恶性肿瘤成像的~(99)Tc和荧光染料的双模式成像探针。将聚酰胺胺包覆的二氧化硅纳米颗粒(PCSNs)与吲哚青绿偶联，然后用~(99m)Tc标记。将抗HER2抗体与标记的PCSN共价结合，将双模式成像探针通过尾静脉注射到荷瘤裸鼠体内。移植的SKBR3肿瘤是HER2高表达的肿瘤，与HER2低表达的移植瘤的低信号相反，SKBR3肿瘤表现出高荧光信号强度。SKBR3肿瘤中的放射性也高于SKBR3肿瘤中的放射性。结果表明，这种双模式成像探头在伽玛射线探测到深部病变后，可能有利于在外科手术中勾勒出具有解剖构型的高荧光病变。

We aimed to develop dual-modality imaging probes with Tc-99m and fluorescent dyes using surface-modified silica nanoparticles for the image of malignant tumors. Polyamidoamine coated silica nanoparticles, PCSNs, were conjugated with indocyanine green and then labeled with Tc-99m. Anti-HER2 antibodies were covalently combined with the labeled PCSNs.The dual-modality imaging probes were injected in athymic mice with xenografted breast tumors through the tail vain. The xenografted SKBR3 tumors, HER2-overexpressing tumors, showed high fluorescence signal-intensities contrast to the low signal-intensities in the xenografted MDA-MB231 tumors in which HER2 expression was low. Radioactivity in the SKBR3 tumors also increased compared to that in the SKBR3 tumors. The results revealed that this dual-modality imaging probes may be beneficial to delineate the high-fluorescent lesions with anatomical configurations in surgical procedures after detection of the deep situated lesions by gamma rays.