Magnetic resonance imaging of single co-labeled mesenchymal stromal cells after intracardial injection in mice

TY - JOUR

T1 - Magnetic resonance imaging of single co-labeled mesenchymal stromal cells after intracardial injection in mice

AU - Salamon, J

AU - Wicklein, D

AU - Didié, M

AU - Lange, Claudia

AU - Schumacher, U

AU - Adam, G

AU - Peldschus, K

N1 - © Georg Thieme Verlag KG Stuttgart · New York.

PY - 2014/4/1

Y1 - 2014/4/1

N2 - PURPOSE: The aim of this study was to establish co-labeling of mesenchymal stromal cells (MSC) for the detection of single MSC in-vivo by MRI and histological validation.MATERIALS AND METHODS: Mouse MSC were co-labeled with fluorescent iron oxide micro-particles and carboxyfluorescein succinimidyl ester (CFSE). The cellular iron content was determined by atomic absorption spectrometry. Cell proliferation and expression of characteristic surface markers were determined by flow cytometry. The chondrogenic differentiation capacity was assessed. Different amounts of cells (n1 = 5000, n2 = 15 000, n3 = 50 000) were injected into the left heart ventricle of 12 mice. The animals underwent sequential MRI on a clinical 3.0 T scanner (Intera, Philips Medical Systems, Best, The Netherlands). For histological validation cryosections were examined by fluorescent microscopy.RESULTS: Magnetic and fluorescent labeling of MSC was established (mean cellular iron content 23.6 ± 3 pg). Flow cytometry showed similar cell proliferation and receptor expression of labeled and unlabeled MSC. Chondrogenic differentiation of labeled MSC was verified. After cell injection MRI revealed multiple signal voids in the brain and fewer signal voids in the kidneys. In the brain, an average of 4.6 ± 1.2 (n1), 9.0 ± 3.6 (n2) and 25.0 ± 1.0 (n3) signal voids were detected per MRI slice. An average of 8.7 ± 3.1 (n1), 22.0 ± 6.1 (n2) and 89.8 ± 6.5 (n3) labeled cells per corresponding stack of adjacent cryosections could be detected in the brain. Statistical correlation of the numbers of MRI signal voids in the brain and single MSC found by histology revealed a correlation coefficient of r = 0.91.CONCLUSION: The study demonstrates efficient magnetic and fluorescent co-labeling of MSC and their detection on a single cell level in mice by in-vivo MRI and histology. The described techniques may broaden the methods for in-vivo tracking of MSC.KEY POINTS: • Detection of single magnetically labeled MSC in-vivo using a clinical 3.0 T MRI is possible.• Fluorescent and magnetic co-labeling does not affect cell vitality.• The number of cells detected by MRI and histology has a high correlation.

AB - PURPOSE: The aim of this study was to establish co-labeling of mesenchymal stromal cells (MSC) for the detection of single MSC in-vivo by MRI and histological validation.MATERIALS AND METHODS: Mouse MSC were co-labeled with fluorescent iron oxide micro-particles and carboxyfluorescein succinimidyl ester (CFSE). The cellular iron content was determined by atomic absorption spectrometry. Cell proliferation and expression of characteristic surface markers were determined by flow cytometry. The chondrogenic differentiation capacity was assessed. Different amounts of cells (n1 = 5000, n2 = 15 000, n3 = 50 000) were injected into the left heart ventricle of 12 mice. The animals underwent sequential MRI on a clinical 3.0 T scanner (Intera, Philips Medical Systems, Best, The Netherlands). For histological validation cryosections were examined by fluorescent microscopy.RESULTS: Magnetic and fluorescent labeling of MSC was established (mean cellular iron content 23.6 ± 3 pg). Flow cytometry showed similar cell proliferation and receptor expression of labeled and unlabeled MSC. Chondrogenic differentiation of labeled MSC was verified. After cell injection MRI revealed multiple signal voids in the brain and fewer signal voids in the kidneys. In the brain, an average of 4.6 ± 1.2 (n1), 9.0 ± 3.6 (n2) and 25.0 ± 1.0 (n3) signal voids were detected per MRI slice. An average of 8.7 ± 3.1 (n1), 22.0 ± 6.1 (n2) and 89.8 ± 6.5 (n3) labeled cells per corresponding stack of adjacent cryosections could be detected in the brain. Statistical correlation of the numbers of MRI signal voids in the brain and single MSC found by histology revealed a correlation coefficient of r = 0.91.CONCLUSION: The study demonstrates efficient magnetic and fluorescent co-labeling of MSC and their detection on a single cell level in mice by in-vivo MRI and histology. The described techniques may broaden the methods for in-vivo tracking of MSC.KEY POINTS: • Detection of single magnetically labeled MSC in-vivo using a clinical 3.0 T MRI is possible.• Fluorescent and magnetic co-labeling does not affect cell vitality.• The number of cells detected by MRI and histology has a high correlation.

KW - Animals

KW - Cardiac Surgical Procedures

KW - Cell Tracking

KW - Cells, Cultured

KW - Contrast Media

KW - Dextrans

KW - Injections

KW - Magnetic Resonance Imaging, Interventional

KW - Magnetite Nanoparticles

KW - Male

KW - Mesenchymal Stem Cell Transplantation

KW - Mesenchymal Stromal Cells

KW - Mice

KW - Mice, Inbred C57BL

KW - Myocardium

KW - Reproducibility of Results

KW - Sensitivity and Specificity

U2 - 10.1055/s-0034-1366097

DO - 10.1055/s-0034-1366097

M3 - SCORING: Journal article

C2 - 24683169

VL - 186

SP - 367

EP - 376

JO - ROFO-FORTSCHR RONTG

JF - ROFO-FORTSCHR RONTG

SN - 1438-9029

IS - 4

ER -