Skip to Content
Merck
  • Iron administration before stem cell harvest enables MR imaging tracking after transplantation.

Iron administration before stem cell harvest enables MR imaging tracking after transplantation.

Radiology (2013-07-16)
Aman Khurana, Fanny Chapelin, Graham Beck, Olga D Lenkov, Jessica Donig, Hossein Nejadnik, Solomon Messing, Nikita Derugin, Ray Chun-Fai Chan, Amitabh Gaur, Barbara Sennino, Donald M McDonald, Paul J Kempen, Grigory A Tikhomirov, Jianghong Rao, Heike E Daldrup-Link
ABSTRACT

To determine whether intravenous ferumoxytol can be used to effectively label mesenchymal stem cells (MSCs) in vivo and can be used for tracking of stem cell transplants. This study was approved by the institutional animal care and use committee. Sprague-Dawley rats (6-8 weeks old) were injected with ferumoxytol 48 hours prior to extraction of MSCs from bone marrow. Ferumoxytol uptake by these MSCs was evaluated with fluorescence, confocal, and electron microscopy and compared with results of traditional ex vivo-labeling procedures. The in vivo-labeled cells were subsequently transplanted in osteochondral defects of 14 knees of seven athymic rats and were evaluated with magnetic resonance (MR) imaging up to 4 weeks after transplantation. T2 relaxation times of in vivo-labeled MSC transplants and unlabeled control transplants were compared by using t tests. MR data were correlated with histopathologic results. In vivo-labeled MSCs demonstrated significantly higher ferumoxytol uptake compared with ex vivo-labeled cells. With electron microscopy, iron oxide nanoparticles were localized in secondary lysosomes. In vivo-labeled cells demonstrated significant T2 shortening effects in vitro and in vivo when they were compared with unlabeled control cells (T2 in vivo, 15.4 vs 24.4 msec; P < .05) and could be tracked in osteochondral defects for 4 weeks. Histologic examination confirmed the presence of iron in labeled transplants and defect remodeling. Intravenous ferumoxytol can be used to effectively label MSCs in vivo and can be used for tracking of stem cell transplants with MR imaging. This method eliminates risks of contamination and biologic alteration of MSCs associated with ex vivo-labeling procedures.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Iron oxide(II,III), magnetic nanoparticles solution, 10 nm avg. part. size, 5 mg/mL in toluene
Sigma-Aldrich
Iron oxide(II,III), magnetic nanoparticles solution, 5 nm avg. part. size, 5 mg/mL in toluene
Sigma-Aldrich
Iron(II,III) oxide, nanopowder, 50-100 nm particle size (SEM), 97% trace metals basis
Sigma-Aldrich
Iron oxide(II,III), magnetic nanoparticles solution, 20 nm avg. part. size, 5 mg/mL in H2O
Sigma-Aldrich
Iron oxide(II,III), magnetic nanoparticles solution, 5 nm avg. part. size, 5 mg/mL in H2O
Sigma-Aldrich
Iron oxide(II,III), magnetic nanoparticles solution, 10 nm avg. part. size, 5 mg/mL in H2O
Sigma-Aldrich
Iron(II,III) oxide, powder, <5 μm, 95%
Sigma-Aldrich
Iron oxide(II,III), magnetic nanoparticles solution, 20 nm avg. part. size, 5 mg/mL in toluene
Sigma-Aldrich
Iron(II,III) oxide, 99.99% trace metals basis