靶向性京尼平交联血红蛋白可视化药物递送系统的研究

In this project, a tumor-targeted and dual-fluorescent drug delivery system was fabricated by genipin-crosslinked hemoglobin and loaded with anti-cancer drug doxorubicin. The stable self-fluorescent chromophore was introduced into the carrier’s skeleton, confirming the accurate location of the delivery system and intuitional reflection of its degradation process. Glutamine groups were decorated into the surface of the delivery system and generated the neutral and hydrophilic surfaces. In the acidic environment of the tumor tissue, a positive-charged surface was launched by the protonation of the amino groups in glutamine, facilitating the cell adhesion and cellular internalization of the glutamine-decorated carriers. Moreover, some cancer cell lines displayed addiction to glutamine, so the glutamine-decorated carriers could be identified and then cellular uptaken by the tumor cells, realizing the tumor-target property of the ensemble system. Fluorescence imaging technique was used to track the drug or self-fluorescent carriers in real time. The fluorescence spectra of the drug and delivery system were unmixed by the multispectral fluorescence imaging to reflect the real-time process of drug release and carrier degradation. Mice bearing the bioluminescent breast tumors were built as tumor model, and the tumor treatment efficacy was evaluated and its correlation with drug release and carrier degradation was also revealed by the bioluminescent imaging. A drug delivery system, which combining the tumor-target and visible fluorescence imaging, could achieve the accurate drug delivery purposes and promote the effective treatment of malignant tumor disease. The research results of this project will provide a good foundation for the design and clinical application of a new drug delivery system.

本项目构建靶向性及双荧光的血红蛋白纳米药物递送系统，负载抗肿瘤药物阿霉素，利用药物的缓释对肿瘤进行有效治疗。京尼平交联的方式在构建血红蛋白纳米粒子的同时，在体系骨架中引入稳定的荧光发色团，有利于载体的成像示踪。体系表面引入谷氨酰胺基团，一方面维持了粒子表面的电中性和亲水性，另一方面由于肿瘤细胞特异性的谷氨酰胺代谢提高了载体的靶向性，有利于载体的细胞摄取。利用荧光成像技术在体实时跟踪，对药物及载体进行多荧光光谱的双重跟踪，研究纳米复合载药系统药物释放及载体降解。以荧光素酶表达的乳腺癌细胞构建乳腺癌肿瘤模型，生物发光影像方法评价肿瘤治疗效果，揭示载体降解及药物释放与肿瘤治疗作用的相互关系。利用一种药物递送体系实现肿瘤靶向性及可视化两种功能的结合，达到精确、准确药物递送的目的，促进恶性肿瘤疾病的有效治疗，为新型药物递送体系的设计和临床应用提供良好的基础，具重要理论和应用价值。

癌症已成为威胁人类健康的恶性疾病之一，为实现良好的肿瘤治疗效果，影像引导和靶向给药是关键。本项目的主要研究内容是构建靶向性及荧光影像引导的药物递送系统，负载抗肿瘤药物，利用影像引导指导治疗进程，实现对肿瘤的有效治疗。本项目综合利用化学修饰、影像技术、药物控释、联合治疗等方法，成功构建靶向性药物递送体系，利用荧光影像引导的方式，实现对恶性肿瘤的精准治疗。在项目执行期间，进行了以下研究工作：（1）影像引导的可视化血红蛋白纳米递送体系，制备双荧光的阿霉素负载的京尼平交联血红蛋白双荧光纳米粒子，利用多光谱荧光成像系统可无扰跟踪其体内药物释放和降解过程，阐明此种纳米递送系统的药物缓释和载体降解过程，从而揭示药物释放及载体降解之间的相关性，指导肿瘤治疗过程中的给药程序。本研究为癌症治疗中可视给药系统的开发开辟了一条新途径。（2）谷氨酰胺修饰的肿瘤靶向药物递送体系，制备了谷氨酰胺修饰的具有pH敏感性的靶向纳米颗粒体系，作为阿霉素和粉防己碱的载体，用于肝癌的靶向治疗。由于肿瘤细胞的“谷氨酰胺成瘾性”行为，谷氨酰胺修饰纳米颗粒可在肝癌细胞系中有效积累。同时，粉防己碱作为化疗增敏剂，可以提高肿瘤细胞对化疗药物阿霉素的敏感性，提高肿瘤治疗效果。此研究中基于肿瘤异常代谢制备的肿瘤靶向给药系统是肝癌协同化疗的一种有前景的策略，也可能是治疗其他类型肿瘤的一种新的有前景的治疗策略。（3）在前两部分研究工作的基础上，开展了功能巨噬细胞介导靶向药物递送系统的研究，利用影像引导和靶向给药实现肿瘤精准治疗。一方面，巨噬细胞自身固有的肿瘤向性，保证了药物成功的靶向输送到肿瘤部位。pH敏感的阿霉素纳米粒负载在避免宿主细胞的细胞毒性的同时，可作为双重治疗药物的递送系统。另一方面，实现实时荧光成像引导，跟踪治疗过程，在成像引导下给药，可达到最佳治疗效果。此种多功能给药系统的构建为联合治疗的精确和靶向给药提供了可能。