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 potential 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 dualmodal stem cell imaging.Methods:Au-Fe3O4 silica NPs were synthesized by seed-mediated growth method and co-precipitation.The efficiency and cytotoxicity of the NPslabeled bone marrow-derived mesenchymal stem cells(BMMSCs)were evaluated by Cell Counting Kit-8 assays,ICPMS,phenotypic characterization,and histological staining.The biodistribution of labeled BM-MSCs injected through different 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 concentration of NPs,the viability of BM-MSCs was 77.91%±5.86%and the uptake of Au and Fe were(22.65±1.82)µg/mL and(234.03±11.47)µg/mL,respectively.The surface markers of labeled BM-MSCs unchanged significantly.Labeled BMMSCs have osteogenic and adipogenic differentiation potential.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 BMMSCs was the optimal route for the treatment of LC.

Angio-Computed Tomograph-Guided Immediate Lipiodol Computed Tomograph for Diagnosis of Small Hepatocellular Carcinoma Lesions during Transarterial Chemoembolization

Background： The diagnosis and treatment of small hepatocellular carcinoma （HCC） play a vital role in the prognosis of patients with HCC. The purpose of our study was to evaluate anglo-computed tomography （angio-CT）-guided immediate lipiodol CT （a CT scan performed immediately after transarterial chemoembolization [TACE]） in the diagnosis of potential HCCs ≤1 cm in diameter. Methods： This study retrospectively analyzed 31 patients diagnosed with HCCs after routine imaging （contrast-enhanced CT or magnetic resonance imaging） or pathologic examinations with undefined or undetermined tumor lesions （diameter 〈1 cm） from February 2016 to September 2016. After TACE guided by digital subtraction angiography of the angio-CT system, potential HCC lesions with a diameter ≤1 cm were diagnosed by immediate lipiodol CT. The number of well-demarcated lesions was recorded to calculate the true positive rate. The correlation between the number of small HCCs detected by immediate lipiodol CT and the size of HCC lesions （diameter 〉1 cm） diagnosed preoperatively was analyzed 1 month after TACE. A paired t-test was used to analyze differences in liver function. Pearson analysis was used to analyze correlation. Chi-square test was used to compare the rates. Results： Fifty-eight lesions were detected on preoperative routine imaging examinations in 31 patients including 15 lesions with a diameter ≤ 1 cm. Ninety-one lesions were detected on immediate lipiodol CT, of which 48 had a diameter ≤ 1 cm. After 1 month, CT showed that 45 lesions had lipiodol deposition and three lesions had lipiodol clearance. Correlation analysis showed that the number of small HCCs detected by lipiodol CT was positively correlated with the size of HCC lesions diagnosed by conventional imaging examination （R^2 - 0.54, P 〈 0.05）. Conclusion： Immediate lipiodol CT may be a useful tool in the diagnosis of potential HCC lesions with a diameter of ≤1 cm.

Unique Solvability for a Class of Non-newtonian Fluids for a Reacting Mixture with Vacuum

In this paper,we consider a class of non-Newtonian fluids for a reacting mixture in one-dimensional bounded interval, provided the initial data satisfying a compatibility condition. The main ingredient is that we allow the initial density vacuum.