基于含TEMPO共轭聚合物的VEGFR-3靶向MR/光学双模态探针对非小细胞肺癌淋巴结转移诊断的研究

Lymph nodes metastasis is the primary metastasis of non-small cell lung cancer, which influences the prognosis. It is important to explore preoperative noninvasive early accurate diagnosis of non-small cell lymph nodes metastasis. However,the preoperative imaging examination is non-specificity and can’t meet clinic demand. Our current data shows that conjugated polymer containing TEMPO exhibits high T1 relaxivity and optical properties, which can be applied as MR/optical imaging probe. In this work, we choose the VEGFR-3 as target which is high expressed in tumor metastatic lymph nodes lymphangiogenesis, attempt to fabricate the VEGFR-3 targeted MR/optical bimodal imaging probe, and investigate the targeted effect to human lymphatic endothelial cells. We establish non-small cell lung cancer lymph nodes metastasis model in nude mice, evaluate the target-specific agent potential use in MR/optical imaging at the metastatic lymph nodes, and confirm the targeted localization in the metastatic lymph nodes and the distribution in lymphatic vessels via pathological examination. We also prepare drug delivery complex via paclitaxel as model drug, to evaluate the targeted therapy for non-small cell lung cancer metastatic lymph nodes. This study will provide a new approach for diagnosis of lung cancer lymph nodes metastasis and supply research guide for targeted therapy and diagnosis of other tumors lymph nodes metastasis.

淋巴结转移是非小细胞肺癌转移的主要途径，影响患者预后。探索早期发现并准确定性非小细胞肺癌淋巴结转移的术前无创诊断方法具有重要意义。目前常用的影像诊断方法缺乏特异性，存在一定假阳性，不能满足临床需求。我们最近的研究显示，含TEMPO共轭聚合物具有良好的光学性能和T1弛豫率，可应用为MR/光学双模态探针。本研究选择在转移性淋巴结内新生淋巴管内皮高表达的VEGFR-3为靶点，采用VEGFR-3抗体修饰含TEMPO共轭聚合物，构建VEGFR-3靶向MR/光学双模态探针，评估体外靶向识别效果；构建非小细胞肺癌淋巴结转移动物模型，研究体内转移性淋巴结靶向双模态成像，证实探针在淋巴结内的靶向位置及与肿瘤新生淋巴管的分布关系。此外，以紫杉醇为模型药物，构建载药复合物，评估肿瘤靶向治疗效果。本项目不仅将为肺癌淋巴结转移的早期诊断鉴别提供新的途径，也为其他肿瘤淋巴结转移的早期定性及定量诊断治疗提供新的思路。

MRI/光学双模态成像将MRI成像和光学成像进行融合，为肿瘤早期诊断、鉴别及疗效监测提供了新的思路和方法。2,2,6,6-四甲基哌啶氧化物(TEMPO)具有超顺磁性，显示良好的T1弛豫率，低细胞毒性和良好的生物相容性，可以应用为MRI探针。在课题执行过程中，先后以TEMPO为MRI对比剂，与多种荧光探针偶联，构建MRI/光学双模态对比剂，用于肿瘤双模态成像；同时构建近红外荧光探针用于细胞器成像，肿瘤长期示踪和治疗。（1）将TEMPO和聚芴偶联，构建了离子化含TEMPO聚芴（PFP-TEMPO+），考察了体外MR/光学双模态成像性能；以A549细胞为模型细胞，检测了细胞毒性和体外细胞摄取情况；构建了荷A549肿瘤裸鼠模型，考察了对肿瘤光学/MRI双模态成像性能。（2）将TEMPO和荧光碳量子点结合，采用葡萄糖修饰，构建了葡萄糖介导的MRI/光学双模态纳米探针，考察了体外MRI/光学双模态成像性能和葡萄糖介导的摄取情况。（3）近红外荧光成像具有穿透深度高，生物组织吸收低，自体荧光较弱等优点，广泛应用在生物成像、肿瘤诊断和术中手术导航。因此，制备了AIE活性近红外有机荧光纳米颗粒TPFE-Rho NPs，检测了体外细胞传代性能，构建了荷肿瘤小鼠模型，研究了探针长期荧光监测肿瘤生长性能。（4）在细胞器成像方面，成功合成了溶酶体靶向近红外荧光探针，实现了检测活体细胞内的粘度和溶酶体近红外荧光成像。（5）在肿瘤治疗方面，合成了具有良好光热转化效率的近红外吸收有机纳米颗粒，实现了肿瘤光声成像和近红外光激发的化学-光热治疗。