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Intracellular processing of silica-coated superparamagnetic iron nanoparticles in human mesenchymal stem cells
journal contributionposted on 2019-03-11, 09:43 authored by Richard Harrison, Veeren M. Chauhan, David Onion, Jonathan W. Aylott, Virginie Sottile
Silica-coated superparamagnetic iron nanoparticles (SiMAGs) are an exciting biomedical technology capable of targeted delivery of cell-based therapeutics and disease diagnosis. However, in order to realise their full clinical potential, their intracellular fate must be determined. The analytical techniques of super-resolution fluorescence microscopy, particle counting flow cytometry and pH-sensitive nanosensors were applied to elucidate mechanisms of intracellular SiMAG processing in human mesenchymal stem cell (hMSCs). Super-resolution microscopy showed SiMAG fluorescently-tagged nanoparticles are endocytosed and co-localised within lysosomes. When exposed to simulated lysosomal conditions SiMAGs were solubilised and exhibited diminishing fluorescence emission over 7 days. The in vitro intracellular metabolism of SiMAGs was monitored in hMSCs using flow cytometry and co-localised pH-sensitive nanosensors. A decrease in SiMAG fluorescence emission, which corresponded to a decrease in lysosomal pH was observed, mirroring ex vivo observations, suggesting SiMAG lysosomal exposure degrades fluorescent silica-coatings and iron cores. These findings indicate although there is a significant decrease in intracellular SiMAG loading, sufficient particles remain internalised (>50%) to render SiMAG treated cells amenable to long-term magnetic cell manipulation. Our analytical approach provides important insights into the understanding of the intracellular fate of SiMAG processing, which could be readily applied to other particle therapeutics, to advance their clinical translation.
This work was supported by the Engineering and Physical Sciences Research Council [grant numbers 1118937, EP/I017801/1, EP/P006485/1], an EPSRC Centre for Doctoral Training (CDT) in Regenerative Medicine grant, EPSRC Engineering, Tissue Engineering and Regenerative Medicine (ETERM) Landscape fellowship grant (RH), and EPSRC for the Future Targeted Healthcare Manufacturing Hub grant (VMC, JWA) respectively; and the Biotechnology and Biological Sciences Research Council [grant number BB/L013827/1], the authors are extremely grateful to Dr Robert Markus for his help with super resolution microscopy, which was conducted in the School of Life Sciences Imaging facility (SLIM) funded by this grant. Financial and in kind support from the consortium of industrial users as part of the EPSRC Future Targeted Healthcare Manufacturing Hub grant is also acknowledged (VMC, JWA). In addition, the work presented in this manuscript was also supported by the University of Nottingham Research Priority Area in Regenerative Medicine and Stem Cells (VMC and RPH, project code: A2RVXX).
- Mechanical, Electrical and Manufacturing Engineering
Published inRSC Advances
Pages3176 - 3184
CitationHARRISON, R.P. ... et al, 2019. Intracellular processing of silica-coated superparamagnetic iron nanoparticles in human mesenchymal stem cells. RSC Advances, 9 (6), pp.3176-3184.
Publisher© Royal Society of Chemistry (RSC)
- VoR (Version of Record)
Publisher statementThis work is made available according to the conditions of the Creative Commons Attribution 3.0 Unported (CC BY 3.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/
NotesThis is an Open Access article. It is published by The Royal Society of Chemistry under the Creative Commons Attribution 3.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/