Comparative Labeling of Equine and Ovine Multipotent Stromal Cells With Superparamagnetic Iron Oxide Particles for Magnetic Resonance Imaging In Vitro.

This research article evaluates the effectiveness of three different superparamagnetic iron oxide particles for labeling bone marrow-derived multipotent stromal cells from sheep and horses in vitro. Researchers assessed their impact on cell characteristics and found all three particles successful for labelling, with two outperforming in various parameters.

Introduction

• In this research, the scientists aimed to test the labeling efficiency of three different superparamagnetic iron oxide (SPIO) types on multipotent stromal cells (MSCs), derived from the bone marrow of horses and sheep.
• The cells were tracked using Magnetic Resonance Imaging (MRI).
• The main goal was to examine the cell proliferation capacity, differentiation potential, and long-term MRI detectability.

Methodology

• Multipotent stromal cells (MSCs) were acquired from five adult sheep and horses. They were processed through three passages (p3).
• The cells were labeled using three different types of SPIO particles: Molday ION Rhodamine B, Resovist, and Endorem. Unlabeled MSCs were used as a control group.

Results

• All three types of SPIO particles were successful in labeling MSCs from both species.
• A high, exclusively intracellular, iron uptake was achieved with only Molday ION Rhodamine B. This means the iron from Molday ION Rhodamine B was absorbed only inside the cells.
• Labeling with Resovist resulted in a noticeable presence of iron on the outside of the cells, while labeling with Endorem was deemed less efficient due to lower intracellular iron uptake.
• All labeled cells produced strong hypointense signals during MRI scans, unlike the unlabeled cells.
• In terms of signal area size, Resovist induced the largest areas of hypointense signals, followed by Molday ION Rhodamine B and Endorem.
• Furthermore, MRI signal detectability gradually decreased from passage 4 to passage 7.
• It was observed that cell labeling did not reduce the cell’s ability to proliferate or differentiate into adipogenic and osteogenic lines. However, the capacity for chondrogenic differentiation decreased with an increasing amount of iron associated with the cells.

Conclusions

• Resovist and Molday were found to be promising labeling agents among the three SPIO products tested. Resovist outperformed in most parameters, but Molday ION Rhodamine B ensured iron absorption solely inside the cells, without extracellular SPIO complexes, and maintained consistent hypointense signals in MRI.
• The finding that cell labeling did not diminish the cell’s ability to proliferate or differentiate into adipogenic and osteogenic lines is significant, as it suggests that the labeling process does not interfere with the normal biological activities of the cells.