Superparamagnetic iron oxide magnetic nanomaterial-labeled bone marrow mesenchymal stem cells for rat liver repair after hepatectomy.

Superparamagnetic iron oxide magnetic nanomaterials (SPIO) are tracers used for treatment of central nervous and cardiovascular system complications in animal models. The present study investigated survival and proliferation of SPIO-labeled bone marrow mesenchymal stem cells (BMSCs) to determine their potential therapeutic value in liver repair. Surface antigens of BMSCs were measured using flow cytometry. BMSCs viability, growth curve, and SPIO (0-100 μg/mL) labeling rate were evaluated using trypan blue staining, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and Prussian blue staining, respectively. SPIO-labeled BMSCs were transplanted via liver or spleen injection in rats undergoing 70% hepatectomy. Distribution of SPIO-labeled BMSCs in liver and spleen, and liver repair were evaluated by magnetic resonance imaging (MRI), and serum alanine aminotransferase, aspartate aminotransferase, albumin, and total bilirubin levels. CD29(+)/CD90(+)/CD45(-) BMSCs were successfully isolated from rats. Labeling rate of SPIO in 25 μg/mL was 94.9%. SPIO labeling did not affect BMSCs survival and proliferation. MRI showed that BMSCs colonized in the liver, whether via spleen or liver injection. Serum levels of alanine aminotransferase, aspartate aminotransferase, and total bilirubin in the transplanted rats were significantly lower than in the hepatectomy group at days 1, 3, and 7 after hepatectomy (all P < 0.05), whereas serum albumin levels were significantly higher in the transplanted rats on posthepatectomy day 3 (both P < 0.05). These indicators were not significantly different between the spleen and liver injection approaches. BMSCs transplantation via liver or spleen injection could significantly accelerate liver healing. In vivo MRI of SPIO-labeled BMSCs can be used to trace real-time liver healing during clinical treatment after hepatectomy.