Ji Sihan, Chen Yaodong, Zhao Xianglong, Cai Yunyu, Zhang Xiaopeng, Sun Feilong, Chen Qi, Deng Qingmei, Wang Changhao, Ma Kun, Hong Bo, Liang Changhao
Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
Biomater Sci. 2021 Apr 7;9(7):2732-2742. doi: 10.1039/d0bm01993c. Epub 2021 Feb 23.
The construction of surface structures of manganese oxide nanoparticles (MONs) in order to promote their longitudinal relaxivity r to surpass those of commercially available Gd(iii) complexes is still a significant challenge. Herein, we successfully obtained MnO/PtO nanocomposites (NCs) with an r of 20.48 mM s, four times higher than that of commercially available Gd-DTPA (5.11 mM s). The r/r ratio of these NCs is 1.46 lower than that of Gd-DTPA (2.38). This is the first time that such excellent T contrast performance has been achieved using MONs via synergistically utilizing the surface morphology and surface payload. These NCs are composed of porous MnO"skeleton" nanostructures decorated with tiny PtO nanoparticles (NPs) that are realized using laser ablation and irradiation in liquid and ion etching steps. Experimental results showed that the enlarged specific area of the porous MnO/PtO NCs and the payload of ultrafine PtO NPs synergistically facilitated the T contrast capabilities. The former favors sufficient proton-electron interactions and the latter reduces the global molecular tumbling motion. These NCs also exhibit an evident computed tomography (CT) attenuation value of 24.13 HU L g, which is much better than that achieved using the commercial product iopromide (15.9 HU L g). The outstanding magnetic resonance (MR) imaging and CT imaging performances of the MnO/PtO NCs were proved through in vivo experiments. Histological examinations and blood circulation assays confirmed the good biosafety of the NCs. These novel findings showcase a brand-new strategy for fabricating excellent MON T contrast agents (CAs) on the basis of the surface structure and they pave the way for their practical clinical applications in dual-modal imaging.
构建氧化锰纳米颗粒（MONs）的表面结构以促进其纵向弛豫率r超过市售钆（III）配合物，仍然是一项重大挑战。在此，我们成功获得了MnO/PtO纳米复合材料（NCs），其r为20.48 mM-1 s-1，比市售钆喷酸葡胺（5.11 mM-1 s-1）高四倍。这些NCs的r/r2比值比钆喷酸葡胺（2.38）低1.46。这是首次通过协同利用表面形态和表面负载，利用MONs实现如此优异的T2对比性能。这些NCs由多孔MnO“骨架”纳米结构组成，表面装饰有微小的PtO纳米颗粒（NPs），这是通过液体中的激光烧蚀和辐照以及离子蚀刻步骤实现的。实验结果表明，多孔MnO/PtO NCs增大的比表面积和超细PtO NPs的负载协同促进了T2对比能力。前者有利于充分的质子-电子相互作用，后者降低了整体分子翻滚运动。这些NCs还表现出明显的计算机断层扫描（CT）衰减值24.13 HU L-1 g-1，远优于市售产品碘普罗胺（15.9 HU L-1 g-1）。通过体内实验证明了MnO/PtO NCs出色的磁共振（MR）成像和CT成像性能。组织学检查和血液循环分析证实了NCs良好的生物安全性。这些新发现展示了一种基于表面结构制造优异MON T2对比剂（CAs）的全新策略，并为其在双模态成像中的实际临床应用铺平了道路。
