Nanoliposome-encapsulated glutathione improves DNA fragmentation of frozen-thawed bull sperm

Backgrand and Aim: The objective was to evaluate effects of liposomes for intracellular delivery and slow release of reduced glutathione (GSH) into bull sperm.Methods: Liposomes containing ۲.۵ Mm GSH were prepared using a thin-film preparation method, then sonicated to achieve different particle size (diameter of > ۵۰, ۵۰-۱۰۰ and <۱۰۰ nm, zeta potential of -۱۹ mv and polydispersity index of ۰.۲۹). In total, ۴۸ ejaculates were obtained from six Holstein bulls. Nanoliposomes containing ۲.۵ mM GSH with different particle size ( >۵۰ (NL۱), ۵۰-۱۰۰ (NL۲) or <۱۰۰ (NL۳) were added to a Tris-based extender prior to semen cryopreservation and compare to Anderomed (control).Results: Encapsulation efficiency was ۸۸.۲۴%. Total and progressive motility and membrane integrity were highest (P < ۰.۰۵) in NL۲ (۸۲.۶ ± ۰.۸ and ۴۸.۱ ± ۱.۰ respectively), but not significantly different from NL۱ (۸۵.۰ ± ۰.۸ and ۴۶.۵ ±۱.۰). Percentage of sperm with a DNA fragmentation was higher (P < ۰.۰۵) in the NL۲ group than in NL۱ and NL۳ (۴.۷ ± ۱.۰, ۵.۵ ± ۱.۰ and ۵.۹ ± ۱.۰%) but not different from Andromed (۴.۲ ± ۱.۰).Conclusion: NL۲ optimized cryosurvival of sperm from Holstein bulls.