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

BACKGROUND: Although application of superparamagnetic iron oxide nanoparticles (SPIONs) in industry and medi- cine has increased, their potential toxicity in reproductive cells remains a controversial issue. This study was under- taken to address the response of sperm, oocyte, and resultant blastocyst to dextran-coated SPIONs (D-SPIONs) treat- ment during 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 D- SPIONs, respectively. Sperm and/or cumulus oocyte complexes (COCs) were cultured for 4 h in this medium for elec- tron microscopic analysis of sperm and COCs, and assessment of developmental competence and genes expression of Gpx1, Sod1, catalase, Bcl2l1 and Bax in the resultant blastocysts. RESULTS: Ultrastructural study of sperm, oocyte, and granulosa showed destructed mitochondria and membranes in spermatozoa, vacuolated mitochondria and distorted cristae in oocytes, and disrupted nuclei and disorganized cell membranes in granulosa in a dose-dependent manner. Data showed that cleavage and blastocyst rates in the 250 µg/ml of 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 the low-dose group, was higher than the controls. CONCLUSION: There is considerable concern regarding D-SPIONs toxic effects on IVF, and mitochondrial and cell membrane damage in mouse spermatozoa and oocytes, which may be related to oxidative stress and apoptotic events.