Prospection of a Nanostructured Magnetic Marker for Tracking Mesenchymal Stem Cells: Efficacy and Safety

Mesenchymal stem cells (MSCs) secrete growth factors and immunomodulators
crucial for physiological and therapeutic processes. Their regenerative abilities,
including migration to injury sites and reparative activity, make them promising for
studies and cellular therapies. A significant challenge associated with the use of
stem cells in patients is tracking the cells post-transplantation. Superparamagnetic
iron oxide nanoparticles (SPIONs) have been explored as markers for in vivo
tracking of cells used in cellular therapies through visualization via magnetic
resonance imaging. Currently, no nanoparticles are approved for cellular tracking in
humans; they are only used in preclinical studies, which opens up opportunities for
the development of new products. The aim of this project is to test the safety and
efficacy of a new nanostructured marker developed for cellular tracking. To this end,
SPIONs synthesized in collaboration with the startup Magtech, referred to here as
MagT, were tested on Wharton's jelly umbilical cord MSCs (WJ-MSCs) and
compared with a commercial nanoparticle, Molday ION Rhodamine B (MIRB). The
labeling efficiency was investigated with Prussian Blue staining, and biocompatibility
was assessed through cell migration, proliferation (immunocytochemistry for Ki67),
and apoptosis (TUNEL) assays. The cells were treated with 25 μg/ml of MIRB or
different concentrations (25, 50, 100 and 200μg/ml) of MagT for 18 hours. In the
Prussian Blue assay, we observed that MIRB labeled 100% of the cells, whereas
MagT did not have the same efficacy in the corresponding group, MagT25, but a
high labeling efficacy was observed in the MagT100 and MagT200 groups. The
scratch closure on the plate in the migration assay occurred in approximately 24
hours, and it was not possible to determine differences between the groups. We did
not observe significant changes in cell proliferation or apoptosis rates, evaluated at 1
and 3 days post-labeling. All results presented here are preliminary, and the study
still includes other assays to be developed, such as cellular differentiation, MTS
assay, and lactate dehydrogenase. Developing nanoparticles nationally is essential
for reducing import dependence and enhancing technological innovation.

This work was supported by CNPq and FAPERJ