A study on labeling efficiency,cellular viability and in vitro MRI of human fibroblast cells labeled with SPIO of different concentration / 重庆医科大学学报

ABSTRACT

Objective:To explore the efficiency of super-paramagnetic iron oxide(SPIO)of different concentrations in vitro labeling human fibroblast cells as well as the influence on cellular viability,and to investigate the characteristics of magnetic resonance imaging.Methods:Respectively mix pure SPIO(concentration of iron200 ?g/ml) and SPIO-PLL compound of different concentrations with substrate(final concentrations of iron150,100,50,25 ?g/ml;final concentration of PLL7.5 ?g/ml).Then incubate it with Hfbs for 12,24,48 h and 72 h.Collect the cells.Assess cellular viability with Trypan Blue Dye Exclusion Method;test iron particles distribution in cells with Prussian blue Stain;observe the positions of iron particles with optical microscope and TEM and calculate the labeling rate of SPIO;perform MR scanning to measure the signal intensity change of the cells.Results:Labeling efficiency of SPIO-PLL compound is much higher than that of pure SPIO(P0.05).Prussian blue Stain test shows there are more or less blue dyed iron particles inside cytoplasm of each labeled cells.And those iron particles concentrate in endosome and lysosome(with electron microscope).Culture solution of concentration in the range of 25～50 ?g Fe/ml is safe for labeling stem cells with SPIO,and 95%～100% of the cells will be effectively labeled in 18～24 h.And the MR scanning shows obvious reduction of signal intensity of the labeled cells.Conclusion:Human fibroblast cells can be easily and safely labeled with self-made SPIO-PLL compound.Labeling with appropriate solution(iron content of 25 ?g/ml) is highly efficient and has little influence on cellular viability,furthermore,with SPIO labeling,the signal intensity of cells scanned with MR is dramatically reduced.