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

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).

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.

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.

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.