Related Experiment Video
Updated: Jul 14, 2026
Labeling hESCs and hMSCs with Iron Oxide Nanoparticles for Non-Invasive in vivo Tracking with MR Imaging
Published on: March 31, 2008
Antibody-mediated cell labeling of peripheral T cells with micron-sized iron oxide particles (MPIOs) allows single
Erik M Shapiro1, Laura N Medford-Davis, Tarek M Fahmy
1Molecular and Cellular Imaging Laboratory, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, USA. erik.shapiro@yale.edu
Abstract:
Labeling cells with iron oxide is a useful tool for MRI based cellular imaging. Here it is demonstrated that peripheral rat T cells can be labeled in whole blood, in vitro, with streptavidin-coated micron-sized iron oxide particles (MPIOs), achieving iron concentrations as high as 60 pg iron per cell. This is 30 times the amount of labeling reported with ultrasmall particles of iron oxide (USPIOs). Labeling was mediated by use of a biotinylated anti-CD5 antibody, which is specific for peripheral T cells. Such labeling allowed the in vitro detection of single lymphocytes by MRI, using conditions well suited for in vivo animal work. Electron microscopic analysis demonstrated that MPIOs remained largely extracellular after labeling, with some evidence of intracellular uptake. Cell viability and early and late cytokine release studies showed no significant differences between labeled and unlabeled cells. Therefore, the use of MPIOs for achieving high iron concentrations for cellular MRI is potentially an effective new modality for non-invasive imaging of lymphocytes.
Insights
Researchers developed a new method using micron-sized iron oxide particles (MPIOs) to label peripheral T cells for MRI. This high-concentration labeling enables sensitive detection of lymphocytes, advancing cellular imaging techniques.
Area of Science:
- Biomedical Imaging
- Cellular Biology
- Nanotechnology
Background:
- Iron oxide nanoparticles are valuable for MRI-based cellular imaging.
- Previous methods using ultrasmall particles of iron oxide (USPIOs) achieved lower labeling concentrations.
- Targeted labeling of specific cell populations is crucial for in vivo imaging.
Purpose of the Study:
- To evaluate the efficacy of micron-sized iron oxide particles (MPIOs) for labeling peripheral rat T cells.
- To achieve significantly higher iron concentrations per cell compared to USPIOs.
- To assess the feasibility of MPIO-labeled T cells for MRI detection.
Main Methods:
- Peripheral rat T cells were labeled in whole blood using streptavidin-coated MPIOs and a biotinylated anti-CD5 antibody.
- Iron concentration per cell was quantified.
- Cellular uptake and distribution of MPIOs were analyzed via electron microscopy.
- Cell viability and cytokine release were assessed to evaluate cellular response.
Main Results:
- High iron concentrations (up to 60 pg iron/cell) were achieved, 30 times greater than with USPIOs.
- MPIOs were primarily extracellular, with some intracellular uptake observed.
- Labeled T cells showed no significant differences in viability or cytokine release compared to unlabeled cells.
- Single lymphocytes labeled with MPIOs were detectable by MRI in vitro.
Conclusions:
- MPIOs enable significantly higher iron loading in T cells compared to USPIOs.
- This high-concentration labeling facilitates sensitive, in vitro detection of lymphocytes via MRI.
- MPIO-based labeling represents a promising new modality for non-invasive in vivo imaging of lymphocytes.
