基于嵌段聚合物修饰的水溶性富勒烯多功能药物载体研究

The development of simple, safe, efficient and multifunctional nano-drug delivery system is one of the frontier and hot research field in bionanotechnology. Based on our research background in biological imaging effects of water-soluble fullerene fluorescent nanoparticles and advantages in the field of biomaterials, we proposed the construction of novel multifunctional nano-drug delivery system based on water-soluble fullerene nanoparticles with fluorescence, which is expected to solve problems in biomedical applications of fullerene，including hydrophilic surface modification, efficient drug loading and multifunctional for imaging and treatment. The water-soluble fullerene nanoparticles with fluorescence are going to be prepared by self-assembling of fullerenes and gadofullerenes with tetraethylene glycol (TEG). Hydrophilic block polymers and targeting molecules are bonded to the surface of the fullerene nanoparticles by chemical bonds. Multifunctional and dual mode molecular imaging probe with high sensitivity and efficient drug loading could be constructed by self-assembling of the composite polymers and anticancer drug. The antitumor activities, targeting effects, drug release kinetics and target magnetic/fluorescence imaging abilities of the fullerene nanoparticles drug delivery system will be studied in detail using tumor cells and tumor bearing mice as models, to evaluate their anti-tumor and biological imaging effects and mechanism comprehensively. This proposal is expected to accelerate the development of biomedical applications of fullerenes and provide novel idea for the design of multifunctional drug carrier material.

发展简单、安全、高效的多功能纳米药物输运系统是当今纳米生物技术研究发展的前沿和热点。本项目以申请人前期在水溶性荧光富勒烯生物成像效应研究领域中的工作为基础，针对富勒烯表面亲水性修饰、药物高效载带、实现集成像和治疗为一体的多功能化等关键问题，提出基于富勒烯水溶性荧光纳米粒子构建新型多功能纳米药物输运系统的研究思路。利用富勒烯、钆基富勒烯与水溶性小分子三缩四乙二醇自组装成水溶性荧光纳米粒子，在纳米粒子的表面化学键合亲水性嵌段聚合物和靶向分子，自组装高效吸附装载抗肿瘤药物，构筑高灵敏度的多功能双模态分子影像探针。以肿瘤细胞和荷瘤小鼠为模型，研究富勒烯纳米靶向给药系统的抗肿瘤活性、靶向效果、药物缓释动力学规律及靶向磁/荧光双模态成像能力，综合评价其抗肿瘤和生物成像效果与机制，实现肿瘤的精准检测与治疗一体化。本项目的开展将有助于富勒烯生物医学应用的发展，为富勒烯药物载体材料的多功能化提供设计依据。

富勒烯及钆基富勒烯纳米材料在药物负载和生物成像领域表现出巨大的应用潜能。本项目利用富勒烯、钆基富勒烯与三缩四乙二醇自组装制备水溶性富勒烯纳米粒子C60-TEGs、C70-TEGs和Gd@C82-TEGs。C60-TEGs和C70-TEGs对DPPH自由基具有良好清除作用，C60-TEGs具有很高ORAC值，约为维生素C的23倍，具有显著的抗氧化活性。Gd@C82-TEGs具有良好的生物相容性和稳定性，体外MRI生物成像测试结果表明，Gd@C82-TEGs的弛豫时间T1的加权弛豫率约为 36.7 mM-1s-1，为临床造影剂Gd-DTPA的6倍。通过薄膜分散法制备新型水溶性良好且载药量高的纳米载药体系DTX/C60-TEGs，药物包封率最高可达92.7%，体外生物成像和细胞毒性作用评价实验结果表明DTX从纳米粒子表面释放后能有效抑制肿瘤细胞的增殖，C60-TEGs能清晰反映细胞的生长状态。制备CUR/C60-TEGs抗氧化药物纳米载药体系，其包封率最高可达93.5%，最大吸附CUR的量为6.25%。CUR/C60-TEGs纳米载药体系对FeCl2和抗坏血酸诱导的大鼠肝脏匀浆中脂质过氧化的抑制作用结果显示CUR/C60-TEGs抗脂质过氧化作用明显强于CUR，且CUR/C60-TEGs能有效抑制肝癌细胞HepG2的增殖，成功构建一种新型抗氧化、抗肿瘤药物纳米给药系统。将亲水性聚合物（H2N-PEG-NH2）和靶向小分子叶酸（FA）连接在C60-TEGs纳米粒子表面，物理吸附CUR，构建CUR/C60-TEGs-PEG-FA靶向纳米给药系统，CUR/C60-TEGs-PEG-FA具有明显的缓释作用，能有效靶向于FR高度表达的人口腔表皮癌KB细胞，是一种同时具有抗肿瘤和抗氧化活性的新型靶向纳米粒子载药体系。制备共载布雷非德菌素A和DTX/C70-TEGs的固体脂质纳米粒，实现两种脂溶性抗肿瘤药物的梯度释放，并利用富勒烯纳米粒子C70-TEGs的生物成像能力构建一种多功能的纳米载药体系。另外，利用三缩四乙二醇上的[O,O]配体与金属钯配位形成五元环结构，实现二氯化钯的配位键合负载，制备一种水溶性富勒烯纳米钯催化剂，高效催化卤代芳烃与芳基硼酸的Suzuki偶联反应绿色合成联苯类化合物，并应用于沙坦联苯、联苯乙酸、二氟尼柳等非甾体类抗炎药的合成工艺中。