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Updated: May 16, 2026
Registered Bioimaging of Nanomaterials for Diagnostic and Therapeutic Monitoring
Published on: December 9, 2010
MRI tracking of macrophages labeled with glucan particles entrapping a water insoluble paramagnetic Gd-based agent
Sara Figueiredo1, Juan Carlos Cutrin, Silvia Rizzitelli
1Department of Molecular Biotechnology and Health Sciences and Molecular and Preclinical Imaging Centers, University of Turin, Turin, Italy.
Purpose:
This study is aimed at demonstrating the in vivo potential of Gd(III)-loaded glucan particles (Gd-GPs) as magnetic resonance imaging (MRI)-positive agents for labeling and tracking phagocytic cells.
Procedure:
GPs were obtained from Saccharomyces cerevisae and loaded with the water-insoluble complex Gd-DOTAMA(C18)2. The uptake kinetics of Gd-GPs by murine macrophages was studied in vitro and the internalization mechanism was assessed by competition assays. The in vivo performance of Gd-GPs was tested at 7.05 T on a mouse model of acute liver inflammation.
Results:
The minimum number of Gd-GPs-labeled J774.A1 macrophages detected in vitro by MRI was ca. 300 cells/μl of agar, which is the lowest number ever reported for cells labeled with a positive T1 agent. Intravenous injection of macrophages labeled with Gd-GPs in a mouse model of liver inflammation enabled the MRI visualization of the cellular infiltration in the diseased area.
Conclusions:
Gd-GPs represent a promising platform for tracking macrophages by MRI as a T1 alternative to the golden standard T2-based iron oxide particles.
Insights
Gd(III)-loaded glucan particles (Gd-GPs) show potential for in vivo tracking of phagocytic cells using MRI. This novel T1-based agent enables visualization of cellular infiltration in inflamed liver tissue.
Area of Science:
- Biomedical Imaging
- Nanotechnology
- Cell Biology
Background:
- Magnetic Resonance Imaging (MRI) is crucial for non-invasive disease diagnosis.
- Tracking phagocytic cells, like macrophages, is vital for understanding inflammatory processes.
- Current MRI contrast agents often rely on T2-based imaging, which can be limited.
Purpose of the Study:
- To evaluate Gd(III)-loaded glucan particles (Gd-GPs) as MRI-positive agents for in vivo cell tracking.
- To demonstrate the potential of Gd-GPs for labeling and monitoring phagocytic cells.
- To establish Gd-GPs as a T1-based alternative to T2-based contrast agents.
Main Methods:
- Glucan particles (GPs) from Saccharomyces cerevisae were loaded with Gd-DOTAMA(C18)2.
- Murine macrophage uptake kinetics and internalization mechanisms of Gd-GPs were studied in vitro.
- In vivo performance of Gd-GPs was assessed using a mouse model of acute liver inflammation at 7.05 T MRI.
Main Results:
- The minimum detectable number of Gd-GPs-labeled macrophages in vitro by MRI was approximately 300 cells/μl, a record low for T1 agents.
- MRI visualization of cellular infiltration in inflamed liver tissue was achieved after intravenous injection of Gd-GPs-labeled macrophages.
- Gd-GPs enabled successful tracking of macrophages in vivo.
Conclusions:
- Gd-GPs offer a promising platform for MRI-based tracking of macrophages.
- Gd-GPs serve as a T1-based contrast agent, providing an alternative to conventional T2-based iron oxide particles.
- This approach enhances the potential for non-invasive monitoring of inflammatory conditions.
