Instituto de Ciencia de Materiales de Sevilla (CSIC-US), c/Américo Vespucio, 49, 41092 Sevilla, Spain.
Biomedical Magnetic Resonance Laboratory-BMRL, Andalusian Public Foundation Progress and Health-FPS, Seville, Spain.
J Mater Chem B. 2024 Nov 6;12(43):11123-11133. doi: 10.1039/d4tb01157k.
Research on high-field magnetic resonance imaging (HF-MRI) has been increased in recent years, aiming to improve diagnosis accuracy by increasing the signal-to-noise ratio and hence image quality. Conventional contrast agents (CAs) have important limitations for HF-MRI, with the consequent need for the development of new CAs. Among them, the most promising alternatives are those based on Dy or Ho compounds. Notably, the high atomic number of lanthanide cations would bestow a high capability for X-ray attenuation to such Dy or Ho-based compounds, which would also allow them to be employed as CAs for X-ray computed tomography (CT). In this work, we have prepared uniform NaDy(WO) and NaHo(WO) nanoparticles (NPs), which were dispersible under conditions that mimic the physiological media and were nontoxic for cells, meeting the main requirements for their use . Both NPs exhibited satisfactory magnetic relaxivities at 9.4 T, thus making them a promising alternative to clinical CAs for HF-MRI. Furthermore, after their intravenous administration in tumor-bearing mice, both NPs exhibited significant accumulation inside the tumor at 24 h, attributable to passive targeting by the enhanced permeability and retention (EPR) effect. Therefore, our NPs are suitable for the detection of tumors through HF-MRI. Finally, NaDy(WO) NPs showed a superior X-ray attenuation capability than iohexol (commercial CT CA), which, along with their high value, makes them suitable as the dual-probe for both HF-MRI and CT imaging, as demonstrated by experiments conducted using healthy mice.
近年来，高磁场磁共振成像（HF-MRI）的研究有所增加，旨在通过提高信噪比从而提高图像质量来提高诊断准确性。传统的造影剂（CA）对 HF-MRI 有重要的局限性，因此需要开发新的 CA。其中，最有前途的替代品是基于 Dy 或 Ho 化合物的 CA。值得注意的是，镧系阳离子的高原子序数将赋予这些基于 Dy 或 Ho 的化合物很高的 X 射线衰减能力，这也使它们能够被用作 X 射线计算机断层扫描（CT）的 CA。在这项工作中，我们制备了均匀的 NaDy（WO）和 NaHo（WO）纳米粒子（NPs），它们在模拟生理介质的条件下具有分散性，且对细胞无毒，满足了它们使用的主要要求。两种 NPs 在 9.4 T 下均表现出令人满意的磁弛豫率，因此有望替代临床 HF-MRI 的 CA。此外，在荷瘤小鼠静脉注射后，两种 NPs 在 24 h 内均在肿瘤内有明显的积累，这归因于增强的通透性和保留（EPR）效应的被动靶向作用。因此，我们的 NPs 适合通过 HF-MRI 检测肿瘤。最后，NaDy（WO）NPs 表现出比碘海醇（商业 CT CA）更高的 X 射线衰减能力，这与其高 值一起，使它们适合作为 HF-MRI 和 CT 成像的双探针，这在使用健康小鼠进行的实验中得到了验证。
