Validity of bone marrow stromal cell expansion by animal serum-free medium for cell transplantation therapy of cerebral infarct in rats-a serial MRI study.

This study was aimed to test the hypothesis that human bone marrow stromal cells (hBMSC) expanded in fetal calf serum (FCS)-free, platelet lysate (PL)-containing medium would retain their capacity of migration, survival, and neural differentiation when transplanted into the infarct brain, using serial in vivo magnetic resonance imaging (MRI). Cell growth kinetic analysis revealed that hBMSC maintain their proliferative activity when cultured either in conventional FCS-containing medium or FCS-free, PL-containing medium. Subsequently, hBMSC were labeled with a superparamagnetic iron oxide agent and were stereotactically transplanted into the ipsilateral striatum of rats at 7 days after permanent middle cerebral artery occlusion. Serial MRI performed over 8 weeks revealed that they retain their migratory capacity towards the cerebral infarct. Moreover, double fluorescence immunohistochemistry also revealed that they preserve their capacity of differentiation into the neural cells in the peri-infarct area. The hBMSC expanded in the FCS-free, PL-containing medium retain their capacity of migration, survival, and differentiation when stereotactically transplanted into the infarct brain. The present findings strongly suggest the clinical utility of PL as a substitute to expand autologous hBMSC for cerebral infarct in the future.