Intra-renal arterial injection of autologous bone marrow mesenchymal stromal cells ameliorates cisplatin-induced acute kidney injury in a rhesus Macaque mulatta monkey model.

BACKGROUND: Clinically, acute kidney injury (AKI) is a potentially devastating condition for which no specific therapy improves efficacy of the repair process. Bone marrow mesenchymal stromal cells (BM-MSCs) are proven to be beneficial for the renal repair process after AKI in different experimental rodent models, but their efficacy in large animals and humans remains unknown. This study aims to assess the effect of autologous rhesus Macaque mulatta monkey BM-MSC transplantation in cisplatin-induced AKI. METHODS: We chose a model of AKI induced by intravenous administration of 5 mg/kg cisplatin. BM-MSCs were transplanted through intra-arterial injection. The animals were followed for survival, biochemistry analysis and pathology. RESULTS: Transplantation of 5 × 10(6) cells/kg ameliorated renal function during the first week, as shown by significantly lower serum creatinine and urea values and higher urine creatinine and urea clearance without hyponatremia, hyperkalemia, proteinuria and polyuria up to 84 d compared with the vehicle and control groups. The superparamagnetic iron oxide nanoparticle-labeled cells were found in both the glomeruli and tubules. BM-MSCs markedly accelerated Foxp3+ T-regulatory cells in response to cisplatin-induced damage, as revealed by higher numbers of Foxp3+ cells within the tubuli of these monkeys compared with cisplatin-treated monkeys in the control and vehicle groups. CONCLUSIONS: These data demonstrate that BM-MSCs in this unique large-animal model of cisplatin-induced AKI exhibited recovery and protective properties.

Synthesis route and three different core-shell impacts on magnetic characterization of gadolinium oxide-based nanoparticles as new contrast agents for molecular magnetic resonance imaging.

Despite its good resolution, magnetic resonance imaging intrinsically has low sensitivity. Recently, contrast agent nanoparticles have been used as sensitivity and contrast enhancer. The aim of this study was to investigate a new controlled synthesis method for gadolinium oxide-based nanoparticle preparation. For this purpose, diethyleneglycol coating of gadolinium oxide (Gd2O3-DEG) was performed using new supervised polyol route, and small particulate gadolinium oxide (SPGO) PEGylation was obtained with methoxy-polyethylene-glycol-silane (550 and 2,000 Da) coatings as SPGO-mPEG-silane550 and 2,000, respectively. Physicochemical characterization and magnetic properties of these three contrast agents in comparison with conventional Gd-DTPA were verified by dynamic light scattering transmission electron microscopy, Fourier transform infrared spectroscopy, inductively coupled plasma, X-ray diffraction, vibrating sample magnetometer, and the signal intensity and relaxivity measurements were performed using 1.5-T MRI scanner.As a result, the nanoparticle sizes of Gd2O3-DEG, SPGO-mPEG-silane550, and SPGO-mPEG-silane2000 could be reached to 5.9, 51.3, 194.2 nm, respectively. The image signal intensity and longitudinal (r1) and transverse relaxivity (r2) measurements in different concentrations (0.3 to approximately 2.5 mM), revealed the r2/r1 ratios of 1.13, 0.89, 33.34, and 33.72 for Gd-DTPA, Gd2O3-DEG, SPGO-mPEG-silane550, and SPGO-mPEG-silane2000, respectively.The achievement of new synthesis route of Gd2O3-DEG resulted in lower r2/r1 ratio for Gd2O3-DEG than Gd-DTPA and other previous synthesized methods by this and other groups. The smaller r2/r1 ratios of two PEGylated-SPGO contrast agents in our study in comparison with r2/r1 ratio of previous PEGylation (r2/r1 = 81.9 for mPEG-silane 6,000 MW) showed that these new three introduced contrast agents could potentially be proper contrast enhancers for cellular and molecular MR imaging.