ABSTRACT
OBJECTIVE: To observe the effect of superparamagnetic iron oxide (SPIO) on the differentiation of rat bone marrow stem cells (BMSCs) into chondrocytes in vitro and explore the possible mechanism. METHODS: CCK8 assay was performed to examine the cytotoxicity of SPIO (1 and 5 µg/mL) on cultured SD rat BMSCs. Prussian blue staining and fluorescence excitation assay were used to assess the binding of the SPIO to BMSCs after the cells had been cultured in chondrocytes-induced medium in the presence of SPIO (1 and 5 µg/mL) for 9 days. The mRNA levels of COL2 α2, aggrecan and MMP13 in the cell culture were examined using Q-PCR, and the chondrogenic differentiation of the BMSCs was analyzed using alcian blue staining and immunofluorescence staining for COL2 α2. The protein levels of COL2 α2, aggrecan, MMP13, Ihh and PTHrP in the cells were examined using Western blotting. RESULTS: CCK8 assay showed no significant toxicity of SPIO on BMSCs. Compared with the control cells, the cells cultured in the presence of SPIO showed increased expressions of COL2 α2 and aggrecan and decreased expression of MMP13 at both mRNA and protein levels with also significantly increased expressions of Ihh and PTHrP proteins. CONCLUSION: SPIO can promote the differentiation of rat BMSCs into chondrocytes and up-regulate the Ihh/PTHrP signal pathway, suggesting the potential of SPIO as a new therapeutic agent for chondrocyte-related diseases.
Subject(s)
Cell Differentiation , Chondrocytes/cytology , Ferric Compounds/pharmacology , Magnetite Nanoparticles , Mesenchymal Stem Cells/cytology , Aggrecans/metabolism , Animals , Bone Marrow Cells/cytology , Bone Marrow Cells/drug effects , Cells, Cultured , Chondrocytes/drug effects , Collagen Type II/metabolism , Matrix Metalloproteinase 13/metabolism , Mesenchymal Stem Cells/drug effects , Rats , Rats, Sprague-DawleyABSTRACT
Multimodal imaging is highly desirable for accurate diagnosis because it can provide complementary information from each imaging modality. In this study, we prepared hybrid gold-gadolinium nanoclusters (NCs), which are ultrasmall, stable, biocompatible, and suitable for triple-modal NIRF/CT/MRI imaging. Upon intravenously injected, the hybrid NCs are effectively accumulated in tumor tissues and quickly clear by renal excretion, indicating their capacity of tumor targeting and low body residues. Notably, the ultrasmall hybrid NCs would penetrate into the solid tumor for capturing its heterostructure and do not induce potential toxicity in vivo. Hence, the well-defined hybrid gold-gadolinium NCs provide a versatile nanoprobe for cancer targeted imaging and diagnosis in vivo.
