目的以转铁蛋白(transferrin,Tf)为模板,氯金酸为原料,原位合成靶向荧光探针-内生型转铁蛋白-金纳米簇(gold nanoclusters,Au NCs),并以前列腺癌(prostate cancer,PCa)为模型,探讨该荧光探针的靶向成像效果。方法利用场发射透射电子显微镜及粒度分析仪分析所合成的荧光探针的形貌、水合粒径及分布;利用紫外-可见分光光度计及荧光分光光度计对其光学性能进行表征;MTT法检测细胞毒性;并通过细胞荧光成像及竞争抑制实验表征其肿瘤的特异性靶向效果;静脉注射Tf-Au NCs至PC-3种植瘤鼠体内,进行连续荧光成像,评价其肿瘤靶向成像效果;通过组织病理学明确其活体毒性。结果本研究制备的Tf-Au NCs粒径约为3 nm,荧光发射峰为700 nm,保留了Tf及金纳米簇的性能;细胞成像结果显示Tf-Au NCs对前列腺肿瘤细胞(PC-3)特异性靶向效果好;小动物活体成像结果显示Tf-Au NCs探针仅需15 min即可准确显示肿瘤部位,至2 h时肿瘤区荧光强度达峰值,表明其具有良好的活体肿瘤成像能力;病理学结果表明Tf-Au NCs具有良好的生物相容性。结论 Tf-Au NCs荧光探针具有良好的光学性能、特异靶向能力,并具有优异的荧光成像能力及良好的生物相容性,将有望应用于PCa的早期影像学分析。 OBJECTIVE: To synthesize gold nanoclusters (Au NCs), a target fluorescent probe, in situ using transferrin (Tf) as a template and chloroauric acid (prostate cancer, PCa) as a model to investigate the imaging effect of this fluorescent probe. Methods The morphology, hydrated size and distribution of the synthesized fluorescent probes were analyzed by field emission transmission electron microscopy and particle size analyzer. The optical properties were characterized by ultraviolet-visible spectrophotometer and fluorescence spectrophotometer. MTT assay Cytotoxicity was detected by fluorescence imaging and competitive inhibition assay. Tf-Au NCs were injected intravenously into PC-3 tumor-bearing mice for continuous fluorescence imaging to evaluate tumor-targeted imaging. Its histotoxicity is clearly identified by histopathology. Results Tf-Au NCs prepared in this study had a size of about 3 nm and a fluorescence emission peak of 700 nm, which preserved the properties of Tf and gold nanoclusters. The results of cell imaging showed that Tf-Au NCs could inhibit the proliferation of prostate cancer cells (PC-3) The result of biopsy showed that Tf-Au NCs probe can accurately display the tumor site in only 15 min, and the peak fluorescence intensity in the tumor area reached the peak value at 2 h, indicating that it has good capability of imaging tumor in vivo ; Pathological results show that Tf-Au NCs has good biocompatibility. Conclusion Tf-Au NCs fluorescent probe has good optical properties, specific targeting ability, excellent fluorescence imaging ability and good biocompatibility. It is expected to be used in the early imaging analysis of PCa.