The development of nanomaterials as highly efficient contrast agents for tumor computed tomography (CT) imaging still remains a huge challenge. In this study, a novel and facile approach to fabricate unimolecular micelles-stablized gold nanoparticles (AuNPs) without external reductant for in vitro targeted CT imaging was described. Amphiphilic 21-arm star-like polymers β-cyclodextrin-g-{poly(2-(dimethylamino)ethyl methacrylate)-poly(2-hydroxyethyl methacrylate)-poly[poly(ethylene glycol) methyl ether methacrylate]} [β-CD-g-(PDMA-b-PHEMA-b-PPEGMA)] was firstly synthesized and proved to form unimolecular core-middle layer-shell-type micelles in water through experimental and computer simulation results. Taking advantage of the reducing groups of PDMA block, AuNPs were decorated in the micellar PDMA block because of the in situ reduction of gold ions, which were absorbed by the PDMA chains in the core layer with a narrow nanoparticle size distribution. This strategy could prevent aggregation of AuNPs, which were capable of being employing as a highly effective probe for specific CT imaging in vitro. Importantly, the β-CD-g-(PDMA-b-PHEMA-b-PPEGMA)/AuNPs incubated with HepG2 cells, displayed more intense X-ray attenuation property (>37%) than conventional iodine-based CT imaging agent (Omnipaque) and also possessed a satisfying cytocompatibility in the given concentration range. The facile fabrication procedures and the efficiency of CT imaging render the novel hybrid unimolecular micelles to become potent candidates for applications in tumor-targeted CT imaging.

纳米材料作为用于肿瘤计算机断层扫描（CT）成像的高效造影剂的发展仍然是一个巨大的挑战。在这项研究中，描述了一种新颖且简便的方法来制备无需外部还原剂的单分子胶束稳定的金纳米颗粒（AuNPs），用于体外靶向CT成像。两亲21臂星形聚合物β-环糊精-g- {聚（甲基丙烯酸2-（二甲基氨基）乙酯）-聚（甲基丙烯酸2-羟乙酯）-聚[聚乙二醇甲基丙烯酸甲酯]} [β-CD -克- （PDMA- b -PHEMA- b-PPEGMA）]的合成，并通过实验和计算机仿真结果证明其在水中形成了单分子核-中间层-壳型胶束。利用PDMA嵌段的还原基团，由于金离子的原位还原，金纳米颗粒被胶束PDMA嵌段修饰，金离子被核心层中的PDMA链吸收，纳米颗粒尺寸分布窄。这种策略可以防止AuNPs聚集，AuNPs可以用作体外特异性CT成像的高效探针。重要的是，β-CD- g-（PDMA- b -PHEMA- b-PPEGMA）/ AuNPs与HepG2细胞孵育，显示出比常规基于碘的CT成像剂（Omnipaque）更强的X射线衰减特性（> 37％），并且在给定的浓度范围内还具有令人满意的细胞相容性。简便的制造程序和CT成像的效率使新型混合单分子胶束成为在靶向肿瘤的CT成像中应用的有效候选者。