In Vitro Toxic Effects of Zinc Oxide Nanoparticles on Rat Adipose Tissue-Derived Mesenchymal Stem Cells.

OBJECTIVE: Zinc oxide nanoparticles (ZnO-NPs) are increasingly used in sunscreens, bio- sensors, food additives, pigments, manufacture of rubber products, and electronic materi- als. There are several studies about the effects of NPs on dermal fibroblast or keratino- cytes, but very little attention has been directed towards adipose-derived mesenchymal stem cells (ASCs). A previous study has revealed that ZnO-NPs restricted the migration capability of ASCs. However, the potential toxicity of these NPs on ASCs is not well un- derstood. This study intends to evaluate the effects of ZnO-NPs on subcutaneous ASCs.

MATERIALS AND METHODS: In this experimental study, In order to assess toxicity, we ex- posed rat ASCs to ZnO-NPs at concentrations of 10, 50, and 100 µg/ml for 48 hours. Tox- icity was evaluated by cell morphology changes, cell viability assay, as well as apoptosis and necrosis detection.

RESULTS: ZnO-NPs concentration dependently reduced the survival rates of ASCs as re- vealed by the trypan blue exclusion and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazo- lium-bromide (MTT) tests. ZnO-NPs, at concentrations of 10 and 50 µg/ml, induced a significant increase in apoptotic indices as shown by the annexin V test. The concentration of 10 µg/ml of ZnO-NPs was more toxic.

CONCLUSION: Lower concentrations of ZnO-NPs have toxic and apoptotic effects on subcutaneous ASCs. We recommend that ZnO-NPs be used with caution if there is a dermatological problem.