双级脑靶向蛋白纳米笼的制备及其在成像引导光热治疗胶质瘤中的应用研究

Cross the blood brain barrier and high targeting glioma is a hot and difficult problem to be resolved in the current research field of glioma treatment. In order to solve the critical problem, this project is based on biological characteristics of glioma, combines the ability of human ferritin nanocage HFn crosses the blood-brain barrier and high specificity of the scorpion chloride toxin CTX for glioma, CTX is modified in N terminal of ferritin by gene engineering method, to build protein nanocage with dual-stage brain target ability of crossing the blood-brain barrier and targeting to glioma, and then in order to obtain the protein nanocage photothermal therapy agent with two-stage brain target ability and imaging guidance function, ICG will be loaded in the interior cavity structure formed in the self-assembly polymerization; cell level research the imaging effect of near infrared fluorescent target for glioma and cytotoxicity, exploration of the blood brain barrier penetration, and the photothermal therapy effect; then establishing the animal model of orthotopic glioma, to study biodistribution, pharmacokinetics, optimization of fluorescent targeted imaging effect,accurately guide photothermal therapy. The successful implementation of this project is expected to establish a new type photothermal preparation both has the abilities of across the blood brain barrier and targeting to glioma, and lay the scientific foundation of the high specificity of glioma targeting treatment.

穿越血脑屏障和高靶向胶质瘤是当前胶质瘤治疗研究领域所亟待解决的热点和难点问题。为解决此关键问题，本项目基于脑胶质瘤的生物学特点，结合人类铁蛋白纳米笼跨越血脑屏障的能力和蝎氯毒素多肽CTX对胶质瘤的高特异性，采用基因工程方法，在铁蛋白的N端修饰上蝎氯毒素多肽CTX，构筑同时具有跨越血脑屏障和脑胶质瘤靶向能力的双级脑靶向蛋白纳米笼；进而利用其自组装聚合后中间形成的空腔结构装载吲哚菁绿染料，以获得具有双级脑靶向和成像引导功能的蛋白纳米笼光热治疗制剂；细胞水平上研究对胶质瘤的近红外荧光靶向成像效果及其细胞毒性，探索对血脑屏障的穿透能力，并研究其光热治疗效果；进而建立动物原位脑胶质瘤模型，研究体内的分布、药代动力学，优化荧光靶向成像效果，精确引导光热治疗。本项目的成功实施有望建立一种同时具有跨越血脑屏障和脑胶质瘤靶向能力的新型光热制剂，并为胶质瘤的高特异性靶向治疗奠定科学基础。

本项目预期研究计划和目标是开发具有高度选择性、靶向性的新型神经胶质瘤诊疗一体化试剂，整个诊疗方法的基础是靶向成像制剂，在研究过程中发现新型二维材料黑磷具备良好的光学性质，是一种更加高效的光热及光声成像制剂，因而在本项目中制备了钛配体修饰黑磷量子点，探究其在肿瘤的光声成像中的应用。体外实验表明，钛配体修饰黑磷量子点具有较好的近红外光学吸收和光声转换性能，在680 nm激光下激发，能有效地对肿瘤细胞成像，具有较高的检测灵敏度。此外，体内光声成像实验证明，在尾静脉注射4 h后，能够准确描绘肿瘤轮廓。研究结果表明，钛配体修饰黑磷量子点具有优秀的光声转换性能，并在生理环境中同样具有良好的稳定性，细胞和动物体内试验均表明，钛配体修饰的黑磷量子点能够高效富集于肿瘤细胞，吸收光声成像的光脉冲，生成可检测到的超声信号，并从中计算出三维的肿瘤图像，提供高分辨率和高对比度的肿瘤组织成像，精确描绘肿瘤轮廓，为实现神经胶质瘤的诊疗一体化打下坚实基础。