Correia Carreira Sara, Armstrong James P K, Okuda Mitsuhiro, Seddon Annela M, Perriman Adam W, Schwarzacher Walther
Bristol Centre for Functional Nanomaterials, University of Bristol;
Department of Materials, Imperial College London.
J Vis Exp. 2016 Dec 13(118):54785. doi: 10.3791/54785.
Many important biomedical applications, such as cell imaging and remote manipulation, can be achieved by labeling cells with superparamagnetic iron oxide nanoparticles (SPIONs). Achieving sufficient cellular uptake of SPIONs is a challenge that has traditionally been met by exposing cells to elevated concentrations of SPIONs or by prolonging exposure times (up to 72 hr). However, these strategies are likely to mediate toxicity. Here, we present the synthesis of the protein-based SPION magnetoferritin as well as a facile surface functionalization protocol that enables rapid cell magnetization using low exposure concentrations. The SPION core of magnetoferritin consists of cobalt-doped iron oxide with an average particle diameter of 8.2 nm mineralized inside the cavity of horse spleen apo-ferritin. Chemical cationization of magnetoferritin produced a novel, highly membrane-active SPION that magnetized human mesenchymal stem cells (hMSCs) using incubation times as short as one minute and iron concentrations as lows as 0.2 mM.
许多重要的生物医学应用，如细胞成像和远程操纵，都可以通过用超顺磁性氧化铁纳米颗粒（SPIONs）标记细胞来实现。实现SPIONs在细胞内的充分摄取是一项挑战，传统上是通过将细胞暴露于高浓度的SPIONs或延长暴露时间（长达72小时）来解决。然而，这些策略可能会介导毒性。在此，我们展示了基于蛋白质的SPION磁铁蛋白的合成以及一种简便的表面功能化方案，该方案能够使用低暴露浓度实现快速细胞磁化。磁铁蛋白的SPION核心由钴掺杂的氧化铁组成，平均粒径为8.2 nm，矿化在马脾脱铁铁蛋白的腔内。磁铁蛋白的化学阳离子化产生了一种新型的、具有高度膜活性的SPION，它能在短至一分钟的孵育时间和低至0.2 mM的铁浓度下使人间充质干细胞（hMSCs）磁化。
