The effect of different concentrations of iron oxide nanoparticles on the expression of p53 gene in human amniotic membrane-derived mesenchymal stem cells  

Superparamagnetic iron oxide nanoparticles (SPIONs) have made extensive advances in nanotechnology. The unique properties of these particles have expanded their application in various fields, including medicine. One of these applications is non-invasive analysis for cell tracking. However, the possibility of toxicity in cells is reported by these nanoparticles. Due to the fact that cellular damage caused by iron oxide nanoparticles is concentration-dependent, the determination of the appropriate  concentration of iron oxide nanoparticles is very important to prevent cell damage or cell death due to apoptosis. The aim of this study was to find a concentration of SPIONs which does not result in apoptosis. Therefore, the effects of different concentrations of iron oxide nanoparticles on cell survival were investigated, and the their effects on increased gene expression involved in apoptosis (p53) in human amniotic membrane derived mesenchymal stem cells (hAMSCs) were evaluated. First, stem cells were extracted from human amniotic membrane tissue and cultured. To demonstrate the multipotent characteristic of hAMSCs, these cells were differentiated into adipose, bone, and chondrocyte cell lines. Then, the viability of the cells treated with different concentrations of iron oxide nanoparticles (200, 150, 100, 50, 0 μg / ml) over a period of 24 and 48 hours was evaluated by MTT method. The effect of the concentrations of 0, 100,150 and 200 μg / ml of nanoparticles after 24 hours in hAMSCs was investigated for the expression of p53 gene by Real-Time PCR. hAMSCs were spindle-shaped in a two-dimensional culture. Flow cytometry examination of surface markers revealed that these cells were able to express CD 29, CD90 and CD105 but they were unable to express CD34 and CD45. The results of the multi-potency assay of hAMSCs showed that these cells were capable of being differentiated into adipocyte, bone and chondrocyte cell lines. Iron oxide nanoparticles had no significant effect on cell survival at the concentrations of 50 and 100 μg / ml in 24 hours. However, cell viability decreased significantly after the concentration of 150 μg / ml (42 ± 1.4%, p<0. 001. The results of Real-Time PCR  analysis showed that the expression of p53 gene significantly increased at concentrations of 150 (2.4±0.1, P < 0. 001) and 200 μg / ml (4.1 ± 0.11, P < 0. 001). According to the results, the nanoparticles used in this study were appropriate at concentrations ≥ 100 μg / ml for cell tracking.