功能性多肽类荧光探针用于肿瘤的标记与检测

From small molecule amino acids, a series of peptide based fluorescent probes containing functional boronic acid groups will be synthesized via the solid phase synthesis (SPS) technique. Through altering the length and the amino acid sequence of peptide chain, the specificity and binding affinity of the probes to different Lewis oligosaccharides will be adjusted. The influence of the kinds and sequences of amino acids on the probe fluorescence will be also extensively investigated. After using MTT assay to evaluate the corresponding cytotoxicity, the selected probe, with low cytotoxicity and high affinity with the Lewis oligosaccharides overexpressed on cancer cells such as sialyl Lewis X and sialyl Lewis A, will be respectively incubated with colon cancer cell line of HT-29, liver cancer cell line of HepG2, hepatoma-derived cell line of Hep3B and African green monkey kidney cell line of COS7. By using confocal laser scanning microscopy and flow cytometry, the tumor cell targeting property and the fluorescent labelling and detecting behaviors of the probes for cancer cells will be evaluated and the probe with the optimal labelling and detecting effect will be screened out. After building the animal tumor model by subcutaneous injection of human cancer cells such as HepG2, the in vivo fluorescent labelling and detecting behaviors will be further investigated.

拟从小分子氨基酸出发，利用多肽固相合成技术合成一系列含硼酸功能基的多肽类荧光探针。通过改变多肽链段长短以及氨基酸的种类，调控探针对不同路易斯寡糖的选择性和结合能力，深入研究不同的氨基酸种类和序列对探针与路易斯寡糖结合后荧光产率的影响。利用MTT法检测荧光探针的生物相容性（细胞毒性），从中筛选出细胞毒性低、与癌细胞表面过度表达的易斯寡糖（如Sialyl Lewis X和Sialyl Lewis A）结合效率高的探针。选取结肠癌细胞（HT-29）、肝癌细胞（HepG2）、肝癌细胞同源细胞Hep3B和非洲绿猴胚胎肾细胞（COS7）为模型细胞，将筛选出的荧光探针分别与其共培养，利用激光共聚焦显微镜和流式细胞仪检测荧光探针靶向标记癌细胞的效果，筛选出低毒高效的多肽类荧光探针。最后，将人源肿瘤细胞（例如HepG2）接种到裸鼠体内并培养裸鼠肿瘤模型，研究筛选出的荧光探针体内肿瘤荧光标记和检测效果。

生物体内及细胞内特定的生化物质与疾病的产生、发展有密切的关联，通过这些特定生化物质的检测可以达到疾病的早期诊断、监测疾病治疗效果等目的。我们设计、合成、构建了系列功能探针，包括用于检测肿瘤及其标志物、以及肿瘤微环境生化物质（如唾液酸糖蛋白、基质金属蛋白酶、凋亡酶、双氧水、超氧阴离子、碱性磷酸酶）的功能化检测探针，用于疾病诊断。通过调控探针的结构与性能，筛选出了多种低毒高效、性能优良的探针材料。并进一步构建了多种诊疗一体化系统，在进行光动力治疗、热疗、化疗、及其联合治疗的同时可以对肿瘤部位的治疗效果进行实时监测。