Department of Chemistry and the Smalley Institute for Nanoscale Science and Technology, Rice University, MS-60, P.O. Box 1892, Houston, TX 77251-1892, USA.
Biomaterials. 2014 Jan;35(2):720-6. doi: 10.1016/j.biomaterials.2013.10.013. Epub 2013 Oct 20.
In this work, the effectiveness of using Gadonanotubes (GNTs) with an external magnetic field to improve retention of transplanted adult mesenchymal stem cells (MSCs) during cellular cardiomyoplasty was evaluated. As a high-performance T1-weighted magnetic resonance imaging (MRI) cell tracking label, the GNTs are gadolinium-loaded carbon nanotube capsules that render MSCs magnetic when internalized. MSCs were internally labeled with either superparamagnetic GNTs or colloidal diamagnetic lutetium (Lu). In vitro cell rolling assays and ex vivo cardiac perfusion experiments qualitatively demonstrated increased magnetic-assisted retention of GNT-labeled MSCs. Subsequent in vivo epicardial cell injections were performed around a 1.3 T NdFeB ring magnet sutured onto the left ventricle of female juvenile pigs (n = 21). Cell dosage, magnet exposure time, and endpoints were varied to evaluate the safety and efficacy of the proposed therapy. Quantification of retained cells in collected tissues by elemental analysis (Gd or Lu) showed that the external magnet helped retain nearly three times more GNT-labeled MSCs than Lu-labeled cells. The sutured magnet was tolerated for up to 168 h; however, an inflammatory response to the magnet was noted after 48 h. These proof-of-concept studies support the feasibility and value of using GNTs as a magnetic nanoparticle facilitator to improve cell retention during cellular cardiomyoplasty.
在这项工作中，评估了在细胞心肌成形术中使用外磁场的 Gadonanotubes（GNTs）提高移植的成年间充质干细胞（MSCs）保留率的效果。作为一种高性能 T1 加权磁共振成像（MRI）细胞示踪标签，GNTs 是负载钆的碳纳米管胶囊，当被内化时使 MSCs 具有磁性。MSCs 被超顺磁 GNTs 或胶体抗磁性镥（Lu）内部标记。体外细胞滚动试验和离体心脏灌注实验定性地证明了 GNT 标记的 MSC 的磁性辅助保留增加。随后在雌性幼年猪的左心室上缝合了一个 1.3 T NdFeB 环形磁铁（n = 21），进行了心外膜细胞注射。通过元素分析（Gd 或 Lu）对收集组织中保留的细胞进行定量，结果表明外部磁铁有助于保留近三倍的 GNT 标记的 MSC 比 Lu 标记的细胞。缝合的磁铁可耐受长达 168 小时；然而，在 48 小时后观察到对磁铁的炎症反应。这些概念验证研究支持使用 GNTs 作为磁性纳米颗粒促进剂来提高细胞在细胞心肌成形术中保留率的可行性和价值。
