Green Synthesis of Copper Nanoparticles using Rosmarinus officinalis L. Extract Improves the Developmental Competence of Mouse Oocytes during in Vitro Maturation.

An effective approach to enrich the in vitro maturation (IVM) of oocyte medium as one of the main assisted reproduction technologies is the use of antioxidants to minimize oxidative stress. This study examined the effects of copper nanoparticles (CuNPs) synthesized by chemical (Ch-NPs) and green (G-CuNPs) methods on the IVM process of mouse oocytes and the development of the embryo in comparison to control oocytes (without nanoparticles treatment). Hydroalcoholic (G-H-CuNPs) and aqueous (G-A-CuNPs) Rosmarinus officinalis extracts were used for green synthesis. Here, Ch-NPs showed much less nuclear maturation and survival rate (44.92 ± 4.52; 66.21 ± 6.22) than the control (73.36 ± 7.40; 89.33 ± 4.40), respectively (P < 0.001). In contrast, G-H-CuNPs treated oocytes exhibited a significant increase (72.28 ± 5.51; 79.37 ± 6.29) compared to the Ch-NPs (P < 0.05). The level of ROS in Ch-NPs exposed oocytes was significantly higher than in the control (P < 0.001). The fertilization rate exhibited a significant elevation in the G-H-CuNPs (96.00 ± 2.45) compared to the control (71.14 ± 5.20) and Ch-NPs (50.00 ± 0.01) (P < 0.05). The 8-cell and blastocyst (BL) rates in the G-H-CuNPs (70.32 ± 3.78) revealed notably higher than those in the control (64.29 ± 3.69) and Ch-NPs (36.67 ± 10.22) (P < 0.05). In summary, results exhibited that G-CuNPs promote mouse oocyte maturation, fertilization, and embryo development more than Ch-NPs. The follow-up studies propose looking into the safety and applicability of green-synthesized CuNPs in human-assisted reproductive technologies.