Cursi Lorenzo, Vercellino Silvia, McCafferty Mura M, Sheridan Emily, Petseva Vanya, Adumeau Laurent, Dawson Kenneth A
Centre for BioNano Interactions, School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland.
UCD Conway Institute of Biomolecular and Biomedical Research, School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.
Nanoscale. 2021 Oct 8;13(38):16324-16338. doi: 10.1039/d1nr04582b.
Despite the high level of interest in bio-nano interactions, detailed intracellular mechanisms that govern nanoscale recognition and signalling still need to be unravelled. Magnetic nanoparticles (NPs) are valuable tools for elucidating complex intracellular bio-nano interactions. Using magnetic NPs, it is possible to isolate cell compartments that the particles interact with during intracellular trafficking. Studies at the subcellular scale rely heavily on optical microscopy; therefore, combining the advantages of magnetic recovery with excellent imaging properties to allow intracellular NP tracking is of utmost interest for the nanoscience field. However, it is a challenge to prepare highly magnetic NPs with a suitable fluorescence for the fluorescence imaging techniques typically used for biological studies. Here we present the synthesis of biocompatible multifunctional superparamagnetic multicore NPs with a bright fluorescent silica shell. The incorporation of an organic fluorophore in the silica surrounding the magnetic multicore was optimised to enable the particles to be tracked with the most common imaging techniques. To prevent dye loss resulting from silica dissolution in biological environments, which would reduce the time that the particles could be tracked, we added a thin dense encapsulating silica layer to the NPs which is highly stable in biological media. The synthesised multifunctional nanoparticles were evaluated in cell uptake experiments in which their intracellular location could be clearly identified using fluorescence imaging microscopy, even after 3 days. The magnetic properties of the iron oxide core enabled both efficient recovery of the NPs from the intracellular environment and the extraction of cell compartments involved in their intracellular trafficking. Thus, the NPs reported here provide a promising tool for the study of the processes regulating bio-nano interactions.
尽管对生物-纳米相互作用有着浓厚的兴趣，但控制纳米级识别和信号传导的详细细胞内机制仍有待阐明。磁性纳米颗粒（NPs）是阐明复杂细胞内生物-纳米相互作用的宝贵工具。使用磁性纳米颗粒，可以分离出颗粒在细胞内运输过程中与之相互作用的细胞区室。亚细胞尺度的研究严重依赖光学显微镜；因此，将磁性回收的优势与出色的成像特性相结合以实现细胞内纳米颗粒追踪，这对纳米科学领域至关重要。然而，制备具有适合用于生物学研究的荧光成像技术的高磁性纳米颗粒是一项挑战。在此，我们展示了具有明亮荧光二氧化硅壳的生物相容性多功能超顺磁性多核纳米颗粒的合成。优化了磁性多核周围二氧化硅中有机荧光团的掺入，以使颗粒能够通过最常见的成像技术进行追踪。为了防止由于二氧化硅在生物环境中溶解导致染料损失，这会减少颗粒可被追踪的时间，我们在纳米颗粒上添加了一层薄而致密的封装二氧化硅层，该层在生物介质中高度稳定。在细胞摄取实验中对合成的多功能纳米颗粒进行了评估，在该实验中，即使在3天后，也可以使用荧光成像显微镜清楚地识别它们在细胞内的位置。氧化铁核心的磁性特性使得既能有效地从细胞内环境中回收纳米颗粒，又能提取参与其细胞内运输的细胞区室。因此，本文报道的纳米颗粒为研究调节生物-纳米相互作用的过程提供了一种有前景的工具。
