General, Visceral, and Transplantation Surgery, Experimental Surgery and Regenerative Medicine, Charité-Campus Virchow, Universitätsmedizin Berlin, Berlin, Germany.
Mol Imaging Biol. 2011 Aug;13(4):613-22. doi: 10.1007/s11307-010-0405-y. Epub 2010 Aug 25.
Magnetic resonance imaging (MRI) is a promising approach for non-invasive monitoring after liver cell transplantation. We compared in vitro labeling of human liver cells with nano-sized (SPIO) and micron-sized iron oxide particles (MPIO).
The cellular iron load was quantified and phantom studies were performed using 3.0-T MRI. Transferrin receptor and ferritin gene expression, reactive oxygen species (ROS) formation, transaminase leakage, and urea synthesis were investigated over 6 days.
Incubation with MPIO produced stronger signal extinctions in MRI at similar iron loads within shorter labeling time. MPIO had no negative effects on the cellular iron homeostasis or cell performance, whereas SPIO caused temporary ROS formation and non-physiologic activation of the iron metabolic pathway.
Our findings suggest that MPIO are suited for clinical translation of strategies for cellular imaging with MRI. Attention should be paid to iron release and oxidative stress caused by biodegradable contrast agents.
磁共振成像（MRI）是一种很有前途的非侵入性肝实质细胞移植后监测方法。我们比较了纳米级（SPIO）和微米级氧化铁颗粒（MPIO）对人肝实质细胞的体外标记。
使用 3.0-T MRI 对细胞内铁含量进行定量，并进行体模研究。转铁蛋白受体和铁蛋白基因表达、活性氧（ROS）形成、转氨酶漏出和尿素合成在 6 天内进行了研究。
在类似的铁负荷下，MPIO 在较短的标记时间内产生了更强的 MRI 信号衰减。MPIO 对细胞内铁稳态或细胞功能没有不良影响，而 SPIO 则导致暂时的 ROS 形成和铁代谢途径的非生理性激活。
我们的研究结果表明，MPIO 适合用于临床转化的 MRI 细胞成像策略。应注意可生物降解的造影剂引起的铁释放和氧化应激。
