中文摘要：

目的研究多肽介导的肿瘤靶向药物载体的制备及其细胞摄取性能。方法以丁二酸酐为手臂将SP5—52多肽共价结合到第4代聚酰胺-胺（PAMAM）型树枝状高分子材料（G4）上，荧光分子异硫氰酸荧光素（FITc）为检测探针，以SP5—52多肽连接G4制备靶向药物载体G4-FITC—SP5—52，以阿霉素（DOX）为模型药物，四甲基偶氮唑盐（MTT）比色试验检测载体的细胞毒性，流式细胞术比较连接SP5—52前后细胞对载体的吸收情况，倒置荧光显微镜观察肿瘤细胞对载体及药物的吸收情况。结果经乙酰化修饰的靶向载体具有良好的生物相容性，在4Ixmot／L浓度下24h的细胞存活率高于80％；流式细胞仪检测结果表明靶向载体对非小细胞肺癌H460细胞具有良好的靶向性，游离SP5—52多肽可以抑制载体的靶向性；靶向载体可以通过物理包埋的方式载阿霉素，并对阿霉素的释放具有缓释作用；倒置荧光显微镜观察结果显示靶向载体可以使阿霉素更大量的进入肿瘤细胞。结论G4-FITC—SP5—52体外展示出了良好的肿瘤靶向性，有可能成为临床肿瘤治疗的靶向药物载体。

英文摘要：

Objective To prepare the cancer targeted drug carrier using SP5-52 peptide conjugated with generation four polyamidoamine （PAMAM） dendrimer, and study its cancer cell targeted capability. Methods SP5-52 peptide was conjugated to generation four PAMAM （G4） with succinic anhydride, and FITC was conjugated to the cancer targeted drug carrier as fluorescent probe. The cell toxicity of the carrier was detected by tetrazolium salt colorimetric test （MTr）. The cellular uptake of G4-FITC and G4-FITC-SPS-52 was measured by flow eytometry. And the cellular uptake of doxorubicin （DOX） by cancer cells was observed by inverted fluorescence microscope. Results The targeted drug carrier modified by acetyl showed good biocompatibility. The cell viability was more than 80% at 4 p.mol/L concentration after 24-hour incubation. Flow cytometry analysis showed that targeted carrier could target non-small cell lung cancer NCI-H460 cells, and free SP5-52 peptide could inhibit the cancer targeted capability of carrier. DOX could be encapsulated into G4-FITC-SPS-52 and showed obvious delayed release. The results of inverted fluorescence microscope showed that targeted carrier could transport more drugs into cancer cells.Conclusion G4-FITC-SPS-52 has good cancer targeting capability in vitro and might be a promising drug carrier for clinical cancer treatment.