Graphene oxide enhances post-thaw sperm quality in tropically-adapted rams

This study investigates the effects of graphene oxide (GO) on the quality of frozen-thawed ram semen. Each of 30 ejaculates from five rams were cryopreserved with a control extender (Optidux®, Reprodux Inc., Brazil) or extender containing GO concentrations at 5, 50, or 100 µg/mL. Post-thaw data were analyzed using Tukey's or Dunn's t test (p < 0.05). Graphene oxide at 5 and 50 µg/mL increased frozen-thawed total (50.4 ± 3.15; 52^.0 ± 2.76 %), and progressive sperm motility (44.2 ± 3.06; 45^.7 ± 2.68 %) vs control (42.0 ± 2.75; 36.7 ± 2.58 %), and sperm viability (56.3 ± 2.17; 57.8 ± 2.82 %) vs control (48.8 ± 2.60 %); and decreased immotile spermatozoa (49.6 ± 3.15; 48.0 ± 2.76 %) vs control (58.0 ± 2.75 %). Both 5 and 100 µg/mL treatments improved DNA integrity (90 ± 0.34; 90.5 ± 0.44 %) vs control (89.1 ± 0.37 %). There were no GO effects on sperm morphology, VCL, VAP. Local motility, an undesirable parameter, increased significantly from 5.42 ± 0.52 % (control) to 6.77 ± 0.43 % (100 µg/mL GO). Supplementation with GO improved post-thaw sperm progressive motility (by up to 24.5 %) and viability (up to 18.4 %), reducing immotile sperm (up to 17.2 %), compared to extender alone. This potentially supports the practical use of GO as an additive to semen extenders.