Developmental competence of bovine oocytes with increasing concentrations of nano-copper and nano-zinc particles during in vitro maturation

摘要

cqvip:Objective: To evaluate copper and zinc concentrations in plasma and follicular fluid from cattle ovaries, and estimate the impact of rational concentrations of copper and zinc oxide nanoparticles (CuO-NPs & ZnO-NPs) supplemented during in vitro maturation (IVM) against DNA damage of cumulus cells, glutathione content in oocytes and on consequent embryo development. Methods: Oocytes were obtained from 2 to 8 mm follicles by aspiration method for IVM. Replicates of experiments were performed on different days, with a separate batch of cumulus oocytes complex for each day. Results: The DNA damage of oocytes and cumulus cells significantly decreased with supplemental CuO-NPs or ZnO-NPs concentrations of 0.7 and 1.0 μg/mL in the IVM medium compared to medium without CuO-NPs or ZnO-NPs (P < 0.01). Total glutathione concentrations in oocytes and cumulus cells significantly increased following supplementation with both 0.7 and 1.0 μg/mL CuO-NPs or ZnO-NPs in comparison with 0 and 0.4 μg/mL CuO-NPs or ZnO-NPs supplemented groups (P < 0.01). Supplementation of CuO-NPs or ZnO-NPs during IVM medium at any concentration had no significant effect on cleavge rate. Both CuO-NPs and ZnO-NPs significantly increased blastocyst rates when oocytes were matured with 0.7, 1.0 μg/mL CuO-NPs concentrations (P < 0.01). In contrast, addition of 1.5 μg/mL of CuO-NPs or ZnO-NPs to the maturation media resulted in detrimental effects on the developmental competence of bovine oocytes confirming toxicity induced by CuO-NPs and ZnO-NPs in high concentrations. Conclusions: CuO-NPs or ZnO-NPs-treated bovine oocytes during IVM show low level of DNA fragmentation and increased intracellular glutathione content of cumulus cells. In vitro embryo development is improved by supplementation of rational concentrations of CuO-NPs or ZnO-NPs to culture media. Toxicity induced by CuO-NPs and ZnO-NPs is confirmed in high concentrations.