中文摘要：

目的探索用精氨酸-甘氨酸-天冬氨酸（RGD）肽段连接的近红外量子点荧光探针对口腔鳞状细胞癌（OSCC）的原位可视化成像情况。方法将含有RGD序列的肽段与发射波长为800 nm的近红外量子点（QD800）偶联,制备QD800-RGD荧光探针。将人颊鳞状细胞癌BcaCD885细胞植入裸鼠颊部皮下建立OSCC模型。用QD800-RGD探针和CD105单克隆抗体对OSCC冰冻切片行直接免疫荧光双重染色,用激光扫描共聚焦显微镜观察QD800-RGD探针与肿瘤新生血管内皮细胞表达的整合素αvβ3的结合情况。将QD800-RGD探针通过尾静脉注射入OSCC模型动物,在不同时间点通过活体成像观察QD800-RGD对OSCC活体原位可视化动态成像情况。在12 h后处死荷瘤鼠取出肿瘤,检测QD800-RGD在体内与肿瘤新生血管内皮细胞表达的整合素αvβ3的结合情况。结果 QD800-RGD探针在体内和体外均能与OSCC肿瘤新生血管内皮细胞表达的整合素αvβ3特异性靶向结合。静脉注射QD800-RGD探针后能对体内OSCC进行清楚地可视化成像,在注射QD800-RGD后0.5-6 h内肿瘤成像最完整,信噪比最高,9 h时肿瘤荧光强度显著减低,但在12 h时仍能看到明显的肿瘤成像。结论以肿瘤新生血管内皮细胞表达的整合素αvβ3为靶点,利用QD800-RGD探针经静脉注射后能对OSCC进行清晰地可视化成像,在OSCC的诊断和个体化治疗等方面有巨大的发展前景。

英文摘要：

Objective To investigate in situ visualization using near-infrared quantum dots（QDs） conjugated with arginineglycine-aspartic acid（RGD） peptide fluorescent probes in oral squamous cell carcinoma（OSCC）. Methods QDs with emission wavelength of 800 nm（QD800） were conjugated with RGD peptides to produce QD800-RGD fluorescent probes. Human OSCC cell line BcaCD885 was inoculated in nude mice cheeks to establish OSCC mouse models. Frozen BcaCD885 tumor slices were immunofluorescence double stained by using QD800-RGD and CD105 monoclonal antibody and were observed using a laser scanning confocal microscope. QD800-RGD was injected into the OSCC models through the tail veins, and the in situ visualization was analyzed at different time points. The mice were sacrificed 12 h after injection to isolate tumors for the ex vivo analysis of probe localization in the tumors. Results QD800-RGD specifically targeted the integrin αvβ3 expressed in the endothelial cells of tumor angiogenic vessels in vitro and in vivo, producing clear tumor fluorescence images after intravenous injection. The most complete tumor images with maximal signal-to-noise ratios were observed 0.5 h to 6 h after injection of the probe and significantly reduced 9 h after the injection. However, the tumor image was still clearly visible at 12 h. Conclusion Using intravenously injected QD800-RGD generates high quality OSCC images when integrin αvβ3, which is expressed in the endothelial cells of tumor angiogenic vessels, is used as the target. The technique offers great potential in the diagnosis and individual treatment of OSCC.