In vivo tracking of dendritic cell (DC) migration to the lymphatic system is essential for evaluating the outcome of DC-based immunotherapies. Novel multimodal imaging strategies with high analytical performance are urgently needed to supply complementary information about the migration and colonization of DCs. In this study, we designed a bimodal imaging agent, namely Au@Prussian blue-Gd@ovalbumin nanoparticles (APG@OVA NPs), for activating DCs and real-time tracking of DC migration process by magnetic resonance imaging (MRI). Moreover, the distribution of the colonized DCs in the lymphatic system was profiled at the single-cell levels based on surface-enhanced Raman scattering (SERS) technique. Methods: In this strategy, PBs as cyanide (CN)-bridged coordination blocks were assembled onto the gold nanoparticles core to provide SERS signal in the Raman-silent region (1800 and 2800 cm -1 ), which could avoid background signal interference. The doping Gd 3 located in the lattice of PB enables the MRI ability with high relaxivity of the probe. Ovalbumin, an egg allergen, was used as an antigen to activate DCs due to its immunological properties. The prepared APG@OVA NP agents were used to activate DCs with high efficacy and to track their migration and distribution in vivo through SERS/MR bimodal imaging. Results: The APG@OVA NP agents could not only enable DC activating and labeling, but also achieve real-time monitoring of DC migration in vivo and accurate profiling of DC distribution in the lymphatic system. MR imaging indicated the time-dependent migration of the APG@OVA NP-labeled DCs from the footpad to the sentinel lymph node. The background-free Raman mapping of the lymph node tissue slice demonstrated that the activated DCs have successfully colonized to the sentinel lymph node. Conclusion: Concerning the high activating efficacy, dual complementary imaging readouts, and low biological toxicity, the APG@OVA NPs act as high-performance tracking agents for DC-based immunotherapies.? The author(s).
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机译：体内跟踪树突状细胞（DC）迁移到淋巴系统对于评估基于DC的免疫疗法的结果至关重要。迫切需要具有高分析性能的新型多式联运成像策略，以提供有关DCS的迁移和定殖的互补信息。在这项研究中，我们设计了一种双峰成像剂，即Au @普鲁士蓝色Gd @ obalbumin纳米颗粒（APG @ OVA NPS），用于通过磁共振成像（MRI）激活DC迁移过程的DC迁移过程的实时跟踪。此外，基于表面增强的拉曼散射（SERS）技术，在单细胞水平下分布淋巴系统中的殖民化DC的分布。方法：在该策略中，将PBS作为氰化物（CN） - 织剂的配位块组装到金纳米颗粒核上，以在拉曼 - 沉默区域（1800和2800cm -1）中提供SERS信号，这可以避免背景信号干扰。位于PB晶格中的掺杂GD 3使得MRI能力具有高松弛率的探针。卵蛋白，一种蛋过敏原，被用作抗原，因为其免疫特性而激活DC。制备的APG @ OVA NP试剂用于激活具有高效力的DCS，并通过SERS / MR Bimodal成像追踪体内的迁移和分布。结果：APG @ OVA NP代理商不仅可以实现DC激活和标记，还可以实现DC迁移的实时监测，并准确地分析淋巴系统中的DC分布。 MR成像表示APG @ OVA NP标记的DC从脚板到Sentinel淋巴结的时间迁移。淋巴结组织切片的无背景拉曼映射证明活化的DC已成功地定植到Sentinel淋巴结。结论：关于高激活疗效，双互补成像读数和低生物毒性，APG @ OVA NPS作为直流直流疗法的高性能跟踪剂。作者。
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