Facile fabrication of zinc oxide nanoparticles for enhanced buffalo sperm parameters during cryopreservation

Abstract

Background: Semen cryopreservation could be enhanced by integration of biocompatible nanomaterials. Conditions in which nanoparticles are synthesized should be taken in consideration to avoid divergences in research results concerning beneficial or toxic effects. The objective of this study was to examine the potential of zinc oxide nanoparticles (ZnONPs) synthesized by simple co-precipitation method for providing protection to buffalo sperm against cryo-damage. Methods: ZnONPs were characterized by means of X-ray diffraction, high resolution transmission electron microscope (HR-TEM), zetasizer and Raman spectroscopy. Semen was collected from six healthy buffalo bulls using artificial vagina and pooled semen samples were diluted with tris-egg yolk-fructose extender only (control) or extender supplemented with 10, 25, 50, 100 and 200 µg/ml of ZnONPs. Results: Sperm motility, membrane integrity and acrosome defects were measured. DNA damage of spermatozoa was evaluated using comet assay. To determine antioxidative role of ZnONPs, malondialdehyde (MDA) level as a biomarker of lipid peroxidation was measured in seminal plasma. Sperm motility, viability index as well as membrane integrity increased with ZnONPs concentrations up to 100 μg/ml. Likewise, no adverse effect was reported on sperm DNA integrity with all concentrations. MDA decreased up to concentration of 100 μg/ml ZnONPs. Notably, adding 25, and 50 μg/ml ZnONPs to extender produced best significant positive effects on semen parameters compared to ZnONPs free group. Conclusion: The results confirm that low concentrations of ZnONPs fabricated by co-precipitation method using water as exchange media could effectively preserve the quality of buffalo bull frozen-thawed sperm by reduction of cryoinjury.

Keywords

• Semen cryopreservation
• Zinc oxide nanoparticles
• Lipid peroxidation
• DNA integrity
• Buffalo bull