Nold Philipp, Hartmann Raimo, Feliu Neus, Kantner Karsten, Gamal Mahmoud, Pelaz Beatriz, Hühn Jonas, Sun Xing, Jungebluth Philipp, Del Pino Pablo, Hackstein Holger, Macchiarini Paolo, Parak Wolfgang J, Brendel Cornelia
Department of Hematology, Oncology and Immunology, Philipps University Marburg, Marburg, Germany.
Department of Physics, Philipps-University of Marburg, Marburg, Germany.
J Nanobiotechnology. 2017 Mar 29;15(1):24. doi: 10.1186/s12951-017-0258-5.
Mesenchymal stromal cells (MSCs) have an inherent migratory capacity towards tumor tissue in vivo. With the future objective to quantify the tumor homing efficacy of MSCs, as first step in this direction we investigated the use of inorganic nanoparticles (NPs), in particular ca. 4 nm-sized Au NPs, for MSC labeling. Time dependent uptake efficiencies of NPs at different exposure concentrations and times were determined via inductively coupled plasma mass spectrometry (ICP-MS).
The labeling efficiency of the MSCs was determined in terms of the amount of exocytosed NPs versus the amount of initially endocytosed NPs, demonstrating that at high concentrations the internalized Au NPs were exocytosed over time, leading to continuous exhaustion. While exposure to NPs did not significantly impair cell viability or expression of surface markers, even at high dose levels, MSCs were significantly affected in their proliferation and migration potential. These results demonstrate that proliferation or migration assays are more suitable to evaluate whether labeling of MSCs with certain amounts of NPs exerts distress on cells. However, despite optimized conditions the labeling efficiency varied considerably in MSC lots from different donors, indicating cell specific loading capacities for NPs. Finally, we determined the detection limits of Au NP-labeled MSCs within murine tissue employing ICP-MS and demonstrate the distribution and homing of NP labeled MSCs in vivo.
Although large amounts of NPs improve contrast for imaging, duration and extend of labeling needs to be adjusted carefully to avoid functional deficits in MSCs. We established an optimized labeling strategy for human MSCs with Au NPs that preserves their migratory capacity in vivo.
间充质基质细胞（MSCs）在体内对肿瘤组织具有内在的迁移能力。为了未来能够量化MSCs的肿瘤归巢效果，作为朝着这个方向迈出的第一步，我们研究了使用无机纳米颗粒（NPs），特别是约4纳米大小的金纳米颗粒（Au NPs）对MSCs进行标记。通过电感耦合等离子体质谱（ICP-MS）测定了在不同暴露浓度和时间下NPs随时间的摄取效率。
根据胞吐的NPs量与最初内吞的NPs量来确定MSCs的标记效率，结果表明在高浓度下，内化的Au NPs会随着时间的推移而被胞吐，导致持续耗尽。虽然暴露于NPs即使在高剂量水平下也不会显著损害细胞活力或表面标志物的表达，但MSCs的增殖和迁移潜力受到了显著影响。这些结果表明，增殖或迁移测定更适合评估用一定量的NPs标记MSCs是否会对细胞造成损害。然而，尽管条件得到了优化，但来自不同供体的MSCs批次中标记效率仍有很大差异，这表明细胞对NPs具有特定的负载能力。最后，我们使用ICP-MS确定了小鼠组织中Au NP标记的MSCs的检测限，并展示了NP标记的MSCs在体内的分布和归巢情况。
尽管大量的NPs提高了成像对比度，但标记的持续时间和范围需要仔细调整，以避免MSCs出现功能缺陷。我们建立了一种用Au NPs标记人MSCs的优化策略，该策略可保留其在体内的迁移能力。
