Manganese-guided cellular MRI of human embryonic stem cell and human bone marrow stromal cell viability.

This study investigated the ability of MnCl₂ as a cellular MRI contrast agent to determine the in vitro viability of human embryonic stem cells (hESC) and human bone marrow stromal cells (hBMSC). Basic MRI parameters including T₁ and T₂ values of MnCl₂-labeled hESC and hBMSC were measured and viability signal of manganese (Mn²⁺)-labeled cells was validated. Furthermore, the biological activity of Ca²⁺-channels was modulated utilizing both Ca²⁺-channel agonist and antagonist to evaluate concomitant signal changes. Metabolic effects of MnCl₂-labeling were also assessed using assays for cell viability, proliferation, and apoptosis. Finally, in vivo Mn²⁺-guided MRI of the transplanted hESC was successfully achieved and validated by bioluminescence imaging. Magn Reson Med, 2009. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]