Quantitative CT and 19F-MRI tracking of perfluorinated encapsulated mesenchymal stem cells to assess graft immunorejection

  • Guan Wang
  • Yingli Fu
  • Steven M. Shea
  • Shashank Sathyanarayana Hegde
  • Dara L. KraitchmanEmail author
Research Article



Peripheral artery disease (PAD) affects 12–14% of the world population, and many are not eligible for conventional treatment. For these patients, microencapsulated stem cells (SCs) offer a novel means to transplant mismatched therapeutic SCs to prevent graft immunorejection. Using c-arm CT and 19F-MRI for serial evaluation of dual X-ray/MR-visible SC microcapsules (XMRCaps) in a non-immunosuppressed rabbit PAD model, we explore quantitative evaluation of capsule integrity as a surrogate of transplanted cell fate.

Materials and methods

XMRCaps were produced by impregnating 12% perfluorooctylbromine (PFOB) with rabbit or human SCs (AlloSC and XenoSC, respectively). Volume and 19F concentration measurements of XMRCaps were assessed both in phantoms and in vivo, at days 1, 8 and 15 after intramuscular administration in rabbits (n = 10), by 3D segmenting the injection sites and referencing to standards with known concentrations.


XMRCap volumes and concentrations showed good agreement between CT and MRI both in vitro and in vivo in XenoSC rabbits. Injected capsules showed small variations over time and were similar between AlloSC and XenoSC rabbits. Histological staining revealed high cell viability and intact capsules 2 weeks after administration.


Quantitative and non-invasive tracking XMRCaps using CT and 19F-MRI may be useful to assess graft immunorejection after SC transplantation.


Quantitative tracking 19F-MRI Encapsulated stem cells Peripheral artery disease Immunorejection 



Fluorine magnetic resonance imaging




Analysis of variance


Balanced steady-state free precession


Digital subtraction angiogram


Field of view


Hematoxylin and eosin


Hounsfield units


Anti-human nuclear antigen


Maximum intensity projection


Mesenchymal stem cells


Peripheral artery disease




Region of interest


Stem cell


Superficial femoral artery


Echo time


Repetition time





Supported by a grant from Siemens AG, National Heart, Lung, and Blood Institute (NIH R33-HL089029), and the Maryland Stem Cell Research Foundation (2008-MDSCRFII-0399).

Author contributions

GW was responsible for acquiring imaging data, image processing algorithm development, statistical analysis, result interpretation, and drafting the initial manuscript. YF was responsible for XMRCaps production, animal model preparation, imaging acquisition, histopathology, and drafting the final manuscript. SMS assisted with study design, MR imaging sequence tuning, and manuscript preparation. SSH assisted with study design, coil tuning, and manuscript preparation. DLK was responsible for study conception design, animal model preparation, image acquisition, interpretation, critical review, and drafting the final manuscript.

Compliance with ethical standards

Conflict of interest

DLK has received research grants from Siemens AG and BTG plc. SMS is a former employee of Siemens Healthcare.

Ethical standards

All animal studies were approved by the Institutional Animal Care and Use Committee.


  1. 1.
    Shammas NW (2007) Epidemiology, classification, and modifiable risk factors of peripheral arterial disease. Vasc Health Risk Manag 3(2):229–234CrossRefGoogle Scholar
  2. 2.
    Tunis SR, Bass EB, Steinberg EP (1991) The use of angioplasty, bypass surgery, and amputation in the management of peripheral vascular disease. N Engl J Med 325(8):556–562. CrossRefGoogle Scholar
  3. 3.
    Tateishi-Yuyama E, Matsubara H, Murohara T, Ikeda U, Shintani S, Masaki H, Amano K, Kishimoto Y, Yoshimoto K, Akashi H, Shimada K, Iwasaka T, Imaizumi T (2002) Therapeutic angiogenesis for patients with limb ischaemia by autologous transplantation of bone-marrow cells: a pilot study and a randomised controlled trial. Lancet 360(9331):427–435CrossRefGoogle Scholar
  4. 4.
    Ransohoff JD, Wu JC (2012) Imaging stem cell therapy for the treatment of peripheral arterial disease. Curr Vasc Pharmacol 10(3):361–373CrossRefGoogle Scholar
  5. 5.
    Kinnaird T, Stabile E, Burnett M, Shou M, Lee C, Barr S, Fuchs S, Epstein S (2004) Local delivery of marrow-derived stromal cells augments collateral perfusion through paracrine mechanisms. Circulation 109(12):1543–1549CrossRefGoogle Scholar
  6. 6.
    Kedziorek DA, Hofmann LV, Fu Y, Gilson WD, Cosby KM, Kohl B, Barnett BP, Simons BW, Walczak P, Bulte JW (2012) X-ray-visible microcapsules containing mesenchymal stem cells improve hind limb perfusion in a rabbit model of peripheral arterial disease. Stem Cells 30(6):1286–1296CrossRefGoogle Scholar
  7. 7.
    Kedziorek DA, Solaiyappan M, Walczak P, Ehtiati T, Fu Y, Bulte JW, Shea SM, Brost A, Wacker FK, Kraitchman DL (2013) Using c-arm X-ray imaging to guide local reporter probe delivery for tracking stem cell engraftment. Theranostics 3(11):916CrossRefGoogle Scholar
  8. 8.
    Arifin DR, Kedziorek DA, Fu Y, Chan KW, McMahon MT, Weiss CR, Kraitchman DL, Bulte JW (2013) Microencapsulated cell tracking. NMR Biomed 26(7):850–859CrossRefGoogle Scholar
  9. 9.
    Barnett BP, Ruiz-Cabello J, Hota P, Liddell R, Walczak P, Howland V, Chacko VP, Kraitchman DL, Arepally A, Bulte JW (2011) Fluorocapsules for improved function, immunoprotection, and visualization of cellular therapeutics with MR, US, and CT imaging. Radiology 258(1):182CrossRefGoogle Scholar
  10. 10.
    Barnett BP, Arepally A, Karmarkar PV, Qian D, Gilson WD, Walczak P, Howland V, Lawler L, Lauzon C, Stuber M, Kraitchman DL, Bulte JW (2007) Magnetic resonance-guided, real-time targeted delivery and imaging of magnetocapsules immunoprotecting pancreatic islet cells. Nat Med 13(8):986–991CrossRefGoogle Scholar
  11. 11.
    Barnett BP, Arepally A, Stuber M, Arifin DR, Kraitchman DL, Bulte JWM (2011) Synthesis of magnetic resonance-, X-ray- and ultrasound-visible alginate microcapsules for immunoisolation and noninvasive imaging of cellular therapeutics. Nat Protoc 6(8):1142–1151CrossRefGoogle Scholar
  12. 12.
    Bulte JW, Kraitchman DL (2004) Iron oxide MR contrast agents for molecular and cellular imaging. NMR Biomed 17(7):484–499. CrossRefGoogle Scholar
  13. 13.
    Fu Y, Azene N, Xu Y, Kraitchman DL (2011) Tracking stem cells for cardiovascular applications in vivo: focus on imaging techniques. Imaging Med 3(4):473–486CrossRefGoogle Scholar
  14. 14.
    Kraitchman DL, Gilson WD, Lorenz CH (2008) Stem cell therapy: MRI guidance and monitoring. J Magn Reson Imaging (JMRI) 27(2):299–310. CrossRefGoogle Scholar
  15. 15.
    Ahrens ET, Bulte JW (2013) Tracking immune cells in vivo using magnetic resonance imaging. Nat Rev Immunol 13(10):755–763CrossRefGoogle Scholar
  16. 16.
    Boehm-Sturm P, Mengler L, Wecker S, Hoehn M, Kallur T (2011) In vivo tracking of human neural stem cells with 19F magnetic resonance imaging. PLoS ONE 6(12):e29040. CrossRefGoogle Scholar
  17. 17.
    Srinivas M, Heerschap A, Ahrens ET, Figdor CG, Vries IJM (2010) 19F MRI for quantitative in vivo cell tracking. Trends Biotechnol 28(7):363–370CrossRefGoogle Scholar
  18. 18.
    Rose LC, Kadayakkara DK, Wang G, Bar-Shir A, Helfer BM, O’Hanlon CF, Kraitchman DL, Rodriguez RL, Bulte JWM (2015) Fluorine-19 labeling of stromal vascular fraction cells for clinical imaging applications. Stem Cells Transl Med 4(12):1472–1481. CrossRefGoogle Scholar
  19. 19.
    Liddell RP, Patel TH, Weiss CR, Lee DS, Matsuhashi T, Brown P, Gabrielson KL, Rodriguez ER, Eng J, Kimura H (2005) Endovascular model of rabbit hindlimb ischemia: a platform to evaluate therapeutic angiogenesis. J Vasc Interv Radiol 16(7):991–998CrossRefGoogle Scholar
  20. 20.
    Otsu N (1975) A threshold selection method from gray-level histograms. Automatica 11(285–296):23–27Google Scholar
  21. 21.
    Fu Y, Azene N, Ehtiati T, Flammang A, Gilson WD, Gabrielson K, Weiss CR, Bulte JW, Solaiyappan M, Johnston PV, Kraitchman DL (2014) Fused X-ray and MR imaging guidance of intrapericardial delivery of microencapsulated human mesenchymal stem cells in immunocompetent swine. Radiology 272(2):427–437. CrossRefGoogle Scholar
  22. 22.
    Bamberg F, Dierks A, Nikolaou K, Reiser MF, Becker CR, Johnson TR (2011) Metal artifact reduction by dual energy computed tomography using monoenergetic extrapolation. Eur Radiol 21(7):1424–1429. CrossRefGoogle Scholar
  23. 23.
    Maki J, Masuda C, Morikawa S, Morita M, Inubushi T, Matsusue Y, Taguchi H, Tooyama I (2007) The MR tracking of transplanted ATDC5 cells using fluorinated poly-l-lysine-CF3. Biomaterials 28(3):434–440. CrossRefGoogle Scholar
  24. 24.
    Srinivas M, Morel PA, Ernst LA, Laidlaw DH, Ahrens ET (2007) Fluorine-19 MRI for visualization and quantification of cell migration in a diabetes model. Magn Reson Med 58(4):725–734. CrossRefGoogle Scholar
  25. 25.
    Khattak SF, Chin KS, Bhatia SR, Roberts SC (2007) Enhancing oxygen tension and cellular function in alginate cell encapsulation devices through the use of perfluorocarbons. Biotechnol Bioeng 96(1):156–166CrossRefGoogle Scholar
  26. 26.
    McGovern KA, Schoeniger JS, Wehrle JP, Ng CE, Glickson JD (1993) Gel-entrapment of perfluorocarbons: a fluorine-19 NMR spectroscopic method for monitoring oxygen concentration in cell perfusion systems. Magn Reson Med 29(2):196–204. CrossRefGoogle Scholar
  27. 27.
    Fu Y, Kedziorek D, Shea S, Ouwerkerk R, Huang G, Ehtiati T, Krieg R, Bulte JWM, Kraitchman DL (2010) Novel 19F MRI and CT trackable microencapsulated mesenchymal stem cells for treating peripheral arterial disease. J Am Coll Cardiol 55(10):2162049. CrossRefGoogle Scholar
  28. 28.
    Hounsfield GN (1980) Computed medical imaging. Med Phys 7(4):283–290. CrossRefGoogle Scholar
  29. 29.
    Prince MR (1994) Gadolinium-enhanced MR aortography. Radiology 191(1):155–164. CrossRefGoogle Scholar
  30. 30.
    Ciarelli MJ, Goldstein SA, Kuhn JL, Cody DD, Brown MB (1991) Evaluation of orthogonal mechanical properties and density of human trabecular bone from the major metaphyseal regions with materials testing and computed tomography. J Orthop Res 9(5):674–682. CrossRefGoogle Scholar
  31. 31.
    González Ballester MÁ, Zisserman AP, Brady M (2002) Estimation of the partial volume effect in MRI. Med Image Anal 6(4):389–405. CrossRefGoogle Scholar
  32. 32.
    González Ballester MÁ, Zisserman A, Brady M (2000) Segmentation and measurement of brain structures in MRI including confidence bounds. Med Image Anal 4(3):189–200CrossRefGoogle Scholar

Copyright information

© European Society for Magnetic Resonance in Medicine and Biology (ESMRMB) 2018

Authors and Affiliations

  • Guan Wang
    • 1
    • 2
  • Yingli Fu
    • 1
  • Steven M. Shea
    • 4
  • Shashank Sathyanarayana Hegde
    • 1
  • Dara L. Kraitchman
    • 1
    • 3
    Email author
  1. 1.Russell H. Morgan Department of Radiology and Radiological ScienceJohns Hopkins UniversityBaltimoreUSA
  2. 2.Electrical and Computer EngineeringJohns Hopkins UniversityBaltimoreUSA
  3. 3.Molecular and Comparative PathobiologyJohns Hopkins UniversityBaltimoreUSA
  4. 4.Department of Radiology, Stritch School of MedicineLoyola University ChicagoChicagoUSA

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