Disruptive chemical doping in a ferritin-based iron oxide nanoparticle to decrease r2 and enhance detection with T1-weighted MRI.
Disruptive chemical doping in a ferritin-based iron oxide nanoparticle to decrease r2 and enhance detection with T1-weighted MRI.
复制标题
在基于铁蛋白的氧化铁纳米粒子中进行破坏性化学掺杂，以降低 r2 并增强 T1 加权 MRI 的检测。
DOI：
10.1002/cmmi.1578
复制
发表时间：
2014
影响因子：
--
通讯作者：
Bennett,KevinM
中科院分区：
文献类型：
--
作者：
ClavijoJordan,MVeronica;Beeman,ScottC;Baldelomar,EdwinJ;Bennett,KevinM
Inorganic doping was used to create flexible, paramagnetic nanoparticle contrast agents forin vivomolecular magnetic resonance imaging (MRI) with low transverse relaxivity (r2). Most nanoparticle contrast agents formed from superparamagnetic metal oxides are developed with highr2. While sensitive, they can have limitedin vivodetection due to a number of constraints withT2orT2*‐weighted imaging.T1‐weighted imaging is often preferred for molecular MRI, but mostT1‐shortening agents are small chelates with low metal payload or are nanoparticles that also shortenT2and limit the range of concentrations detectable withT1‐weighting. Here we used tungsten and iron deposition to form doped iron oxide crystals inside the apoferritin cavity to form a WFe nanoparticle with a disordered crystal and un‐coupled atomic magnetic moments. The atomic magnetic moments were thus localized, resulting in a principally paramagnetic nanoparticle. The WFe nanoparticles had no coercivity or saturation magnetization at 5 K and sweeping up to ±20 000 Oe, while native ferritin had a coercivity of 3000 Oe and saturation at ±20 000 Oe. This tungsten–iron crystal paramagnetism resulted in an increased WFe particle longitudinal relaxivity (r1) of 4870 mm−1s−1and a reduced transverse relaxivity (r2) of 9076 mm−1s−1compared with native ferritin. The accumulation of the particles was detected withT1‐weighted MRI in concentrations from 20 to 400 nmin vivo, both injected in the rat brain and targeted to the rat kidney glomerulus. The WFe apoferritin nanoparticles were not cytotoxic up to 700 nmparticle concentrations, making them potentially important for targeted molecular MRI. Copyright © 2014 John Wiley & Sons, Ltd.
