共载SPION和阿霉素的EGFR靶向多功能胶束对肝癌靶向诊断与治疗的研究

Hidden occurrence of Hepatocellular carcinoma (HCC),treatment and prognosis are poor, early diagnosis and effective treatment become the key. Targeting cells can be monitored non-invasively by Magnetic resonance imaging(MRI) with high resolution and good image contrast. As a new MRI contrast agent with good biological characteristics, superparamagnetic iron oxide nanoparticles (SPION) can be combined with polymeric micelles for anticancer drug delivery and targeting ligands for targeted diagnosis and therapy of tumors. Chitosan-oleyl micelles encapsulating SPIONs with good biocompatibility and stability are prepared by our laboratory, and we can modify drugs and targeting ligands on their surface. Epidermal growth factor receptor (EGFR) as a potential important therapeutic target is highly expressed in HCC and closely related to the morbidity and mortality of HCC.In conclusion, this topic intends to prepare targeting EGFR containing multifunctional micelles with anti-cancer drugs and through in vitro cell experiments and Hepatocellular Carcinoma animal model evaluate that whether EGFR targeting micelles containing SPION and doxorubicin with specific magnetic resonance diagnosis has significant anti-tumor effects of Hepatocellular Carcinoma at the same time, and provide a new method for MRI diagnosis and treatment of Hepatocellular Carcinoma.

肝癌发病隐匿，治疗效果及预后较差，早期诊断及有效的治疗成为关键。MRI分辨率高、图像对比度良好，可以从分子水平对靶细胞进行无创监测。超顺磁性氧化铁纳米粒子(SPION)作为一种新型的MRI造影剂，具有良好的生物特性，可以和聚和物胶束联合应用于抗癌药物传递和靶向配体相结合，可实现对肿瘤的靶向诊断和治疗。前期我们合成壳聚糖-油酸聚合物胶束，胶束核内包载SPION，可提高SPION的稳定性和生物相容性，表面形成的核壳结构可进一步搭载药物或靶向配体。研究表明表皮生长因子受体(EGFR)在肝癌中高表达，与肝癌的形成、发生和发展有密切的关系，是潜在的重要靶点。因此，本课题拟制备靶向EGFR同时包载抗癌药物的多功能纳米胶束，通过体外细胞实验及肝癌动物模型，评估共载SPION和阿霉素的EGFR靶向胶束对肝癌具有特异性磁共振诊断的同时，对肝癌是否有明显的抗肿瘤作用，为肝癌MRI诊断及治疗提供新方法。

目的：本文旨在探讨靶向肝细胞癌(HCC)细胞表面表皮生长因子受体（EGFR）的超顺磁性氧化铁纳米粒子（SPION）的核磁共振成像（MRI）能力。方法：本文将GE11肽缀合到壳聚糖（Chitosan CS）修饰的油酸（oleic acid）-SPION 上以构建EGFR-CSO-SPION胶束。通过X线衍射（XRD），透射电子显微镜（TEM），红外光谱、水合粒径，Zeta电位,震动样品磁强计对其进行表征。运用MTT法分析胶束细胞毒性，荧光显微镜及流式细胞术分析GE11肽对肝癌细胞的靶向性，通过普鲁士蓝染色观察细胞与胶束的结合情况，体外及体内MRI实验检测其成像能力。结果：EGFR-CSO-SPION胶束为类球形，大小均匀无明显聚集的纳米粒子。荧光显微镜及流式细胞仪显示GE11肽对EGFR高表达的SMMC-7721细胞和HepG2细胞具有高度特异性。细胞摄取实验显示HepG2细胞对EGFR-CSO-SPION胶束具有较好的吞噬效果，体外及体内MRI结果显示其具有较好的成像效果。结论： EGFR-CSO-SPION胶束可以作为MRI造影剂用于检测EGFR高表达的HCC，为HCC的早期诊断提供可靠的数据。