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. 2016 Dec;5(12):1668-1675.
doi: 10.5966/sctm.2015-0379. Epub 2016 Jul 26.

Biodistribution and Clearance of Human Mesenchymal Stem Cells by Quantitative Three-Dimensional Cryo-Imaging After Intravenous Infusion in a Rat Lung Injury Model

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Free PMC article

Biodistribution and Clearance of Human Mesenchymal Stem Cells by Quantitative Three-Dimensional Cryo-Imaging After Intravenous Infusion in a Rat Lung Injury Model

Eric G Schmuck et al. Stem Cells Transl Med. .
Free PMC article

Abstract

: Cell tracking is a critical component of the safety and efficacy evaluation of therapeutic cell products. To date, cell-tracking modalities have been hampered by poor resolution, low sensitivity, and inability to track cells beyond the shortterm. Three-dimensional (3D) cryo-imaging coregisters fluorescent and bright-field microcopy images and allows for single-cell quantification within a 3D organ volume. We hypothesized that 3D cryo-imaging could be used to measure cell biodistribution and clearance after intravenous infusion in a rat lung injury model compared with normal rats. A bleomycin lung injury model was established in Sprague-Dawley rats (n = 12). Human mesenchymal stem cells (hMSCs) labeled with QTracker655 were infused via jugular vein. After 2, 4, or 8 days, a second dose of hMSCs labeled with QTracker605 was infused, and animals were euthanized after 60, 120, or 240 minutes. Lungs, liver, spleen, heart, kidney, testis, and intestine were cryopreserved, followed by 3D cryo-imaging of each organ. At 60 minutes, 82% ± 9.7% of cells were detected; detection decreased to 60% ± 17% and 66% ± 22% at 120 and 240 minutes, respectively. At day 2, 0.06% of cells were detected, and this level remained constant at days 4 and 8 postinfusion. At 60, 120, and 240 minutes, 99.7% of detected cells were found in the liver, lungs, and spleen, with cells primarily retained in the liver. This is the first study using 3D cryo-imaging to track hMSCs in a rat lung injury model. hMSCs were retained primarily in the liver, with fewer detected in lungs and spleen.

Significance: Effective bench-to-bedside clinical translation of cellular therapies requires careful understanding of cell fate through tracking. Tracking cells is important to measure cell retention so that delivery methods and cell dose can be optimized and so that biodistribution and clearance can be defined to better understand potential off-target toxicity and redosing strategies. This article demonstrates, for the first time, the use of three-dimensional cryo-imaging for single-cell quantitative tracking of intravenous infused clinical-grade mesenchymal stem cells in a clinically relevant model of lung injury. The important information learned in this study will help guide future clinical and translational stem cell therapies for lung injuries.

Keywords: Biodistribution; Cell tracking; Cryo-imaging; Lung injury; Mesenchymal stem cell; Quantum dots.

Figures

Figure 1.
Figure 1.
Schematic of the study design. Animals were treated with bleomycin 4 days apart (days −8 and −4). On day 0, all animals received an intravenous infusion of human mesenchymal stem cells (hMSCs) loaded with QT655. On the day of assigned long-term tissue collection (day 2, 4, or 8) each animal received a second dose of hMSCs loaded with QT605. Animals were then euthanized at 60, 120, or 240 minutes after the infusion of QT605. Each group contains three animals for each time point except for the control animals, which had one animal at each time point. Abbreviations: d, day; MSC, mesenchymal stem cell.
Figure 2.
Figure 2.
Overall human mesenchymal stem cell (hMSC) retention at short- and long-term time points. Short-term (60, 120, and 240 minutes after infusion) and long-term (2, 4, and 8 days after cell infusion) cell retention in all organs collected after an IV infusion of hMSCs. Data are presented as mean ± SEM of the percentage of cells detected in the tissue that was collected versus the total number of viable cells infused.
Figure 3.
Figure 3.
Biodistribution of human mesenchymal stem cells (hMSCs) at early and late time points. The total number of cells detected at each time point is represented as percentage of cells by location after an IV infusion of labeled hMSCs infused at 60, 120, and 240 minutes (early biodistribution) (A) and 2, 4, and 8 days (late biodistribution) (B). Data are presented as mean ± SEM.
Figure 4.
Figure 4.
Representative fluorescence images with overlaid detected cells for different organs, along with zoomed-in views. (A): Lungs; yellow circles represent detected human mesenchymal stem cells (hMSCs). (B): Magnified image from red box in A. (C): Liver; yellow circles represent detected hMSCs. (D): Magnified image from red box in C. (E): Spleen; yellow circles represent detected hMSCs. (F): Magnified image from red box in E.
Figure 5.
Figure 5.
Intraorgan cellular biodistribution 60 minutes postinfusion. (A): 3D bright field reconstruction of lungs. (B): 3D bright field reconstruction with an overlay of detected mesenchymal stem cells (MSCs) from fluorescence. (C): 3D reconstruction showing detected MSCs from fluorescence.
Figure 6.
Figure 6.
Representative fluorescence images with overlaid detected cells for different organs, along with zoomed-in views. (A): Heart; yellow circles represent detected human mesenchymal stem cells (hMSCs). (B): Magnified image from red box in A. (C): Kidney; yellow circles represent detected hMSCs. (D): Magnified image from red box in C.
Figure 7.
Figure 7.
Percentage of cell retention at an early biodistribution (60, 120, and 240 minutes) in the lungs of healthy rats or those treated with two doses of bleomycin. Data presented as mean ± SEM (p = .27).

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References

    1. Ankrum J, Karp JM. Mesenchymal stem cell therapy: Two steps forward, one step back. Trends Mol Med. 2010;16:203–209. - PMC - PubMed
    1. Frangioni JV, Hajjar RJ. In vivo tracking of stem cells for clinical trials in cardiovascular disease. Circulation. 2004;110:3378–3383. - PubMed
    1. Nguyen PK, Riegler J, Wu JC. Stem cell imaging: From bench to bedside. Cell Stem Cell. 2014;14:431–444. - PMC - PubMed
    1. Neuwelt A, Sidhu N, Hu CA, et al. Iron-based superparamagnetic nanoparticle contrast agents for MRI of infection and inflammation. AJR Am J Roentgenol. 2015;204:W302–W313. - PMC - PubMed
    1. Mahmoudi M, Hosseinkhani H, Hosseinkhani M, et al. Magnetic resonance imaging tracking of stem cells in vivo using iron oxide nanoparticles as a tool for the advancement of clinical regenerative medicine. Chem Rev. 2011;111:253–280. - PubMed

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