MRI/PAI Dual-modal Imaging-guided Precise Tracking of Bone Marrow-derived Mesenchymal Stem Cells Labeled with Nanoparticles for Treating Liver Cirrhosis

Background and Aims: Stem cell transplantation is a po-tential treatment option for liver cirrhosis (LC). Accurately and noninvasively monitoring the distribution, migration, and prognosis of transplanted stem cells using imaging methods is important for in-depth study of the treatment mechanisms. Our study aimed to develop Au-Fe3O4 silica nanoparticles (NPs) as tracking nanoplatforms for dual -modal stem cell imaging. Methods: Au-Fe3O4 silica NPs were synthesized by seed-mediated growth method and co-precipitation. The efficiency and cytotoxicity of the NPs-labeled bone marrow-derived mesenchymal stem cells (BM-MSCs) were evaluated by Cell Counting Kit-8 assays, ICP-MS, phenotypic characterization, and histological staining. The biodistribution of labeled BM-MSCs injected through dif-ferent routes (the hepatic artery or tail vein) into rats with LC was detected by magnetic resonance imaging (MRI), photoacoustic imaging (PAI), and Prussian blue staining. Results: Synthesized Au-Fe3O4 silica NPs consisted of a core (star-shaped Au NPs) and an outside silica layer doped with Fe3O4 NPs. After 24 h coincubation with 2.0 OD concentra-tion of NPs, the viability of BM-MSCs was 77.91%+/- 5.86% and the uptake of Au and Fe were (22.65 +/- 1.82) mu g/mL and (234.03 +/- 11.47) mu g/mL, respectively. The surface markers of labeled BM-MSCs unchanged significantly. Labeled BM-MSCs have osteogenic and adipogenic differentiation po-tential. Post injection in vivo, rat livers were hypointense on MRI and hyperintense on PAI. Prussian blue staining showed that more labeled BM-MSCs accumulated in the liver of the hepatic artery group. The severity of LC of the rats in the hepatic artery group was significantly alleviated. Conclusions: Au-Fe3O4 silica NPs were suitable MRI/PAI dual-modal imaging nanoplatforms for stem cell tracking in regenerative medicine. Transhepatic arterial infusion of BM-MSCs was the optimal route for the treatment of LC.