The effects of superparamagnetic iron oxide nanoparticles-labeled mesenchymal stem cells in the presence of a magnetic field on attenuation of injury after heart failure.

Migration of stem cells after transplantation reduces their therapeutic effects. In this study, we hypothesized that superparamagnetic iron oxide nanoparticles (SPION)-labeled mesenchymal stem cells (MSCs) in the presence of magnetic field may have a capability to increase regenerative ability after heart failure (HF). A rat model of ISO (isoproterenol)-HF was established to investigate the effects of SPION-labeled MSCs on tissue regeneration in the presence and absence of magnetic field. Hydrodynamic size, shape, and formation of chemical bonds between SPION and polyethylene glycol (PEG) were measured using dynamic light scattering (DLS), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FTIR). The MRI was used to monitor SPION-labeled MSCs in vivo. Cell and tissue uptake of nanoparticles were determined by Prussian blue staining, atomic absorption spectroscopy (AAS), and inductively coupled plasma spectroscopy (ICP). Purity of the MSCs, heart function, myocardial fibrosis, and histologic damage were evaluated using flow-cytometry, echocardiography, Masson's trichrome, and H&E staining respectively. Various spectroscopic and microscopic analyses revealed that hydrodynamic size of SPION was 40 ± 2 and their shape was spherical. FTIR confirmed the presence of PEG on the surface of nanoparticles. The presence of magnetic field significantly increased cell homing. Highly purified MSCs population was detected by flow-cytometry. Using SPION-labeled MSCs in the presence of magnetic field markedly improved heart function and myocardial hypertrophy and reduced fibrosis (p < 0.05). Collectively, our results demonstrated that SPION-labeled MSCs in the presence of magnetic field might contribute to regeneration after HF.