RESUMO
BACKGROUND: Superparamagnetic iron oxide (SPIO) labeling technology is a classic noninvasive tracing method, which has been widely used in the stem cell transplantation. Induced pluripotent stem cells (iPSCs) are currently one of the most promising seed cells for cell transplantation. Whether SPIO labeling can also be used to noninvasively trace induced pluripotent stem cells is rarely reported, and concern has been raised about whether SPIO markedly impacts the differentiation of iPSCs. OBJECTIVE:To investigate the effects of SPIO labeling on the differentiation of iPSCs in vitro. METHODS: Rat fibroblasts were isolated and cultured. Efficient recombinant vector and plasmids that were packaged by virus and contained target genes (Oct4, Sox2, Klf4 and c-Myc) were transfected into 293T cells for virus packaging and production. The packaging lentiviral vectors that contained target genes infected rat fibroblasts to obtain iPSCs. SPIO-labeled (experimental) or unlabeled (control) iPSCs were subjected to neural induction and differentiation. Prussian blue staining and transmission electron microscope observation were performed for SPIO-labeled iPSCs. Immunohistochemical method was used to detect neuron-specific enolase expression after induced differentiation. Flow cytometry was used to detect the proportion of neurons and glial cells differentiated from iPSCs. RESULTS AND CONCLUSION: There were dense iron particles in the cytoplasm of SPIO-labeled iPSCs shown by Prussian staining and under transmission electron microscope. Differentiated iPSCs were positive for neuron-specific enolase. In addition, the proportion of neurons and glial cells showed no difference between the experimental and control groups. To conclude, SPIO labeling has no obvious effect on the capacity of iPSCs differentiating into neurons. Reasonable application of this new cell labeling technique will promote the development of seed cells in regenerative medicine.