Effects of Dextran-Coated Superparamagnetic Iron Oxide Nanoparticles on Mouse Embryo Development, Antioxidant Enzymes and Apoptosis Genes Expression, and Ultrastructure of Sperm, Oocytes and Granulosa Cells

Abstract

Background: Although application of superparamagnetic iron oxide nanoparticles (SPIONs) in industry and medicinehas increased, their potential toxicity in reproductive cells remains a controversial issue. This study was undertakento address the response of sperm, oocyte, and resultant blastocyst to dextran-coated SPIONs (D-SPIONs) treatmentduring murine in vitro fertilization (IVF).Materials and Methods: In this experimental study, murine mature oocytes were randomly divided into three groups:control, and low- and high-dose groups in which fertilization medium was mixed with 0, 50 and 250 μg/ml of DSPIONs,respectively. Sperm and/or cumulus oocyte complexes (COCs) were cultured for 4 h in this medium for electronmicroscopic analysis of sperm and COCs, and assessment of developmental competence and genes expression ofGpx1, Sod1, catalase, Bcl2l1 and Bax in the resultant blastocysts.Results: Ultrastructural study of sperm, oocyte, and granulosa showed destructed mitochondria and membranes inspermatozoa, vacuolated mitochondria and distorted cristae in oocytes, and disrupted nuclei and disorganized cellmembranes in granulosa in a dose-dependent manner. Data showed that cleavage and blastocyst rates in the 250 μg/mlof D-SPIONs were significantly lower than in the control group (p <0.05). Gene expression of GPx1, Sod1, catalase,Bcl2l1 and Bax in resultant blastocysts of the high-dose group and catalase and Bax in resultant blastocysts of thelow-dose group, was higher than the controls.Conclusion: There is considerable concern regarding D-SPIONs toxic effects on IVF, and mitochondrial and cellmembrane damage in mouse spermatozoa and oocytes, which may be related to oxidative stress and apoptotic events.

Keywords

• apoptosis
• nanoparticles
• oocytes
• oxidative stress
• spermatozoa