RESUMEN
Objective: the label and detection of cells injected into target tissues is an area of focus for researchers. Iron oxide nanoparticles can be used to label cells as they have special characteristics. The purpose of this study is to examine the effects of iron oxide nanoparticles on human-derived amniotic membrane stem cell [hAMCs] survival and to investigate the magnetic properties of these nanoparticles with increased contrast in magnetic reso-nance imaging [MRI]
Materials and Methods: in this experimental study, we initially isolated mesenchymal stem cells from amniotic membranes and analyzed them by flow cytometry. In addition, we synthesized superparamagnetic iron oxide nanoparticles [SPIONs] and characterized them by various methods. The SPIONs were incubated with hAMCs at concentrations of 25-800 [micro]g/mL. The cytotoxicity of nanoparticles on hAMCs was measured by the MTT assay. Next, we evaluated the effectiveness of the magnetic nanoparticles as MRI contrast agents. Solutions of SPION were prepared in water at different iron concentrations for relaxivity measurements by a 1.5 Tesla clinical MRI instrument
Results: the isolated cells showed an adherent spindle shaped morphology. Polyethylene glycol [PEG]-coated SPIONs exhibited a spherical morphology. The average particle size was 20 nm and magnetic saturation was 60 emu/g. Data analysis showed no significant reduction in the percentage of viable cells [97.86 +/- 0.41%] after 72 hours at the 125 [micro]g/ml concentration compared with the control. The relaxometry results of this SPION showed a transverse relaxivity of 6.966 [[micro]g/ml.s][-1]
Conclusion: SPIONs coated with PEG used in this study at suitable concentrations had excellent labeling efficiency and biocompatibility for hAMCs
RESUMEN
Friedreich ataxia [FA] is an autosomal recessive disorder. Cause of about 2-4% of disease is a GAA triplet repeat expansion in the one allele and carries a point mutation as the other allele. This study was performed to investigate exons of FXN gene to find point mutations for the first time in Iran. In this descriptive study, 50 patients suspected to FA who referred to Special Medical Center were investigated. Genomic DNA was investigated by different PCR methods, including PCR for intron, Long PCR and PCR for exons of FXN gene. Then, products were sequenced and finally sequences were analyzed by related software. C to G nucleotide in intron 2 nt:825954, and T to C in intron 3 nt:832729 of FRDA gene were observed by sequencing method. Nucleotide G insertion was detected in exon 5a nt: 822225. Our study showed that diagnosis of FA is not simple because of clinical overlapping with other ataxia, some mutations in intron maybe affect on the disease which need more examination, and because of consanguinity marriage in Iran, some patients with homozygote mutation may show FA phenotype