Ultrastructural characterization of mesenchymal stromal cells labeled with ultrasmall superparamagnetic iron-oxide nanoparticles for clinical tracking studies

TY - JOUR

T1 - Ultrastructural characterization of mesenchymal stromal cells labeled with ultrasmall superparamagnetic iron-oxide nanoparticles for clinical tracking studies

AU - Hansen, Louise

AU - Hansen, Alastair B

AU - Mathiasen, Anders B

AU - Ng, Michael

AU - Bhakoo, Kishore

AU - Ekblond, Annette

AU - Kastrup, Jens

AU - Friis, Tina

PY - 2014/8

Y1 - 2014/8

N2 - INTRODUCTION: To evaluate survival and engraftment of mesenchymal stromal cells (MSCs) in vivo, it is necessary to track implanted cells non-invasively with a method, which does not influence cellular ultrastructure and functional characteristics. Iron-oxide particles have been applied for cell tracking for years, but knowledge regarding possible cytotoxic ultrastructural changes subsequent to iron-oxide particle labeling is limited. Hence, the purpose of this study was to label MSCs with dextran-coated ultrasmall super-paramagnetic iron-oxide (USPIO) particles conjugated with the transduction sequence of trans-activator of transcription (TAT) (IODEX-TAT) and evaluate the effect of labeling on ultrastructure, viability, phenotype and proliferative capacity of the cells.MATERIALS AND METHODS: MSCs were labeled with 5 and 10 μg IODEX-TAT/10(5) cells for 2, 6 and 21 hours. IODEX-TAT uptake and cellular ultrastructure were determined by electron microscopy. Cell viability was determined by propidium iodide staining and cell proliferation capacity by 5-bromo-2-deoxyuridine (BrdU) incorporation. Maintenance of stem cell surface markers was determined by flow cytometry. Results. IODEX-TAT labeling for 2, 6 and 21 h did not influence cellular ultrastructure or viability. Moreover, neither stem cell surface markers nor cell proliferation capacity was affected by labeling with IODEX-TAT.CONCLUSION: Our results demonstrate that labeling of MSCs for 21 h with a clinically relevant dose of 10 μg IODEX-TAT/10(5) cells is feasible and does not affect MSC ultrastructure, viability, phenotype or proliferation capacity.

AB - INTRODUCTION: To evaluate survival and engraftment of mesenchymal stromal cells (MSCs) in vivo, it is necessary to track implanted cells non-invasively with a method, which does not influence cellular ultrastructure and functional characteristics. Iron-oxide particles have been applied for cell tracking for years, but knowledge regarding possible cytotoxic ultrastructural changes subsequent to iron-oxide particle labeling is limited. Hence, the purpose of this study was to label MSCs with dextran-coated ultrasmall super-paramagnetic iron-oxide (USPIO) particles conjugated with the transduction sequence of trans-activator of transcription (TAT) (IODEX-TAT) and evaluate the effect of labeling on ultrastructure, viability, phenotype and proliferative capacity of the cells.MATERIALS AND METHODS: MSCs were labeled with 5 and 10 μg IODEX-TAT/10(5) cells for 2, 6 and 21 hours. IODEX-TAT uptake and cellular ultrastructure were determined by electron microscopy. Cell viability was determined by propidium iodide staining and cell proliferation capacity by 5-bromo-2-deoxyuridine (BrdU) incorporation. Maintenance of stem cell surface markers was determined by flow cytometry. Results. IODEX-TAT labeling for 2, 6 and 21 h did not influence cellular ultrastructure or viability. Moreover, neither stem cell surface markers nor cell proliferation capacity was affected by labeling with IODEX-TAT.CONCLUSION: Our results demonstrate that labeling of MSCs for 21 h with a clinically relevant dose of 10 μg IODEX-TAT/10(5) cells is feasible and does not affect MSC ultrastructure, viability, phenotype or proliferation capacity.

U2 - 10.3109/00365513.2014.900698

DO - 10.3109/00365513.2014.900698

M3 - Journal article

C2 - 24734781

SN - 0036-5513

VL - 74

SP - 437

EP - 446

JO - Scandinavian Journal of Clinical & Laboratory Investigation

JF - Scandinavian Journal of Clinical & Laboratory Investigation

IS - 5

ER -