基于规整蛋白组装体的靶向抗肿瘤药物载体的研究

Tabacco mosaic virus (TMV) coat protein and its rod or disk assembly with well-defined struture will be developed for the construction of an anti-cancer drug delivery system having high selectivity, high efficiency and low toxicity. Combined with gene engineering and chemical modification, TMV coat protein conjugates that have anti-cancer drugs, tumor targeting moiety and in vivo imaging groups could assemble into drug delivery system with monodispersed size and controllable structure. In this drug delivery system constructed by protein-assembling, each function unit has a highly tunable site in space. Attributed to the rod or disk morphology, the loaded drugs in central channel could be triggered released in response to the in vivo environment (such as pH value, redox and so on) through the open-ends, and they could also be protected by the protein assembly avoiding of pharmacological action before being released out at targeting sites. In this project, we would study the stimuli-responsive drug release behavior, anti-cancer efficiency, cytotoxicity, histological toxicity, pharmocokinetics and the tumor-targeting ability for the drug delivery system. Based on this research, a new method will be emerged for the construction of anti-cancer drug delivery system with tumor targeting from various protein assemblies.

本项目拟利用烟草花叶病毒（TMV）衣壳蛋白及其规整棒状、盘状组装结构为研究对象，结合基因改性和化学改性的方法，将抗癌药物、肿瘤靶向单元以及体内成像单元进行组装和调控，从而制备结构可控、粒子尺寸单一的高选择性、高效率、低毒副作用的抗肿瘤药物载体。该药物载体通过蛋白组装的方式构建，各功能基的空间位置可以精确调控。棒状或盘状蛋白组装体的形貌既可以使装载于内腔的药物通过开放的两端响应体内环境（如pH值、还原性等），又可以保护药物在到达靶向部位并释放之前不产生任何药理作用。该项目将详细研究所得抗肿瘤药物载体的药物释放行为、抗癌效率、细胞及组织毒性、药代动力学及对肿瘤的靶向能力，为利用各种规整蛋白组装体研制靶向抗肿瘤药物载体提供新的思路和方向。

作为规整蛋白组装体，棒状的烟草花叶病毒（TMV）和细丝状的噬菌体M13具有各向异性但完全单分散的形貌、完全一致的表面物化性质、可实现精确位点修饰的蛋白外壳，且对人类不具有致病性，因此是药物载体的理想选择。该项目以TMV及M13为研究对象：（1）通过构建基于TMV及M13的细胞内比率式pH荧光探针，研究了TMV及M13这两种规整蛋白组装体对哺乳动物细胞的胞吞机制，为病毒类药物载体的研究提供了理论基础；（2）以多肽或寡糖为靶向分子，设计并制备了两种基于TMV的肿瘤靶向药物输送体系，实现了化疗药物阿霉素及顺铂的高效低毒输送；（3）借助于TMV与多四苯乙烯基有机铂金属大环之间的静电相互作用，构建了可逆并且具有发光效应的多级自组装生物复合体，有可能对蛋白类药物的输送提供崭新的思路。