量子点-前列腺干细胞抗原荧光探针对膀胱癌细胞的靶向成像研究

Targeting imaging of bladder urotheliai cancer cells with quantum dots - prostate stem cell antigen fluorescent probes

目的制备量子点标记的抗人单克隆抗体前列腺干细胞抗原（PSCA）荧光探针（QDs-PSCA），观察其对膀胱癌细胞的特异性标记成像，分析活体内肿瘤非侵人性的靶向成像的可行性。方法采用化学共价耦联的方法，制备氨基水溶性的硒化镉／硫化锌（CdSe／ZnS）发射波长为605nm的量子点（QD605）-PSCA单抗荧光探针，测定探针的吸收光谱、发射光谱；采用直接免疫荧光法（一步法）检测QD605-PSCA荧光探针对膀胱癌EJ细胞的特异性标记能力，荧光显微镜下观察不同时间点探针对活细胞的标记情况。结果QD605-PSCA荧光探针仍具有游离QD605的光学特性，该探针能够与膀胱癌细胞表面抗原PSCA特异性结合，活细胞标记特异性荧光主要表达在细胞膜，且荧光稳定，持续时间较长。结论量子点标记的PSCA单抗荧光探针具有膀胱癌细胞特异性标记成像能力，且具有良好的光学稳定性。

Objective To prepare the fluorescent probes of quantum dots conjugated with prostate stem cell antigen （PSCA） monoclonal antibody （QDs -PSCA）, study their specific labeling imaging of bladder cancer cells, analyze the feasible of non - invasive tumor - targeted imaging in viva, provide the experimental basis for non - invasive tumor - targeted imaging in vivo. Methods The method of chemical covalent coupling was used to prepare QD605 - PSCA fluorescent probes, then, the absorption spectrum ancl emission spectrum of probes were measured. Direct immunofluorescence labeling was utilized to detect the targeted imaging of the probes for bladder cancer EJ cells and observe the duration of the fluorescence after labeling. Results The QD605 - PSCA probes still had fluorescent properties of QI）605. The probes could specifically recognize PSCA protein in bladder cancer cells, the specific fluorescence was mainly ex- pressed in the cell membrane of living cells, the fluorescence was stable and had a longer duration. Con- clusion The QDs - PSCA fluorescent probes could have the ability of specific targeted labeling and ima- ging with bladder cancer ceils, and the probes possess good optical stability. This is contributed to the re- search development of bladder cancer - targeted non - invasive imaging in vivo, tumor early diagnosis and targeted therapy.