Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland, 4072, Australia.
ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, The University of Queensland, Brisbane, Queensland, 4072, Australia.
Small. 2019 Sep;15(36):e1902309. doi: 10.1002/smll.201902309. Epub 2019 Jul 22.
F magnetic resonance imaging ( F MRI) agents capable of being activated upon interactions with cancer triggers are attracting increasing attention, although challenges still remain for precise and specific detection of cancer tissues. In this study, a novel hybrid F MRI agent for pH-sensitive detection of breast cancer tissues is reported, a composite system designed by conjugating a perfluoropolyether onto the surface of manganese-incorporated layered double hydroxide (Mn-LDH@PFPE) nanoparticles. The F NMR/MRI signals from aqueous solutions of Mn-LDH@PFPE nanoparticles are quenched at pH 7.4, but "turned on" following a reduction in pH to below 6.5. This is due to partial dissolution of Mn from the Mn-LDH nanoparticles and subsequent reduction in the effect of paramagnetic relaxation. Significantly, in vivo experiments reveal that an intense F MR signal can be detected only in the breast tumor tissue after intravenous injection of Mn-LDH@PFPE nanoparticles due to such a specific activation. Thus pH-activated Mn-LDH@PFPE nanoparticles are a potential "smart" F MRI agent for precise and specific detection of cancer diseases.
具有与癌症触发相互作用后被激活能力的 F 磁共振成像（F MRI）造影剂越来越受到关注，尽管仍然存在用于精确和特异性检测癌症组织的挑战。在这项研究中，报告了一种用于 pH 敏感检测乳腺癌组织的新型混合 F MRI 造影剂，该复合系统通过将全氟聚醚接枝到锰掺杂层状双氢氧化物（Mn-LDH@PFPE）纳米粒子的表面上设计而成。Mn-LDH@PFPE 纳米粒子在水溶液中的 F NMR/MRI 信号在 pH 7.4 时被猝灭，但在 pH 降低至 6.5 以下时“打开”。这是由于 Mn 从 Mn-LDH 纳米粒子中部分溶解以及顺磁弛豫效应的降低所致。重要的是，体内实验表明，由于这种特异性激活，只有在静脉注射 Mn-LDH@PFPE 纳米粒子后，才能在乳腺癌组织中检测到强烈的 F MR 信号。因此，pH 激活的 Mn-LDH@PFPE 纳米粒子是用于精确和特异性检测癌症疾病的潜在“智能”F MRI 造影剂。
