Preparation, characterization, and ex-vivo evaluation of curcumin-loaded niosomal nanoparticles on the equine sperm quality during cooled storage

Oxidative damage to sperm during cooled storage is a significant issue, and curcumin, with its antioxidant properties, could be a solution. However, its low bioavailability presents a challenge that this study aims to address. The primary objective of this study was to investigate the potential of curcumin-loaded niosomal nanoparticles (Cur-LNN) to enhance the antioxidant properties of curcumin and its effect on sperm quality during 72 h cooled storage. The thin-film hydration procedure was applied to prepare Cur-LNN. The fabricated noisomal nanocarriers were characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), and Fourier-transform infrared (FT-IR) spectroscopy. Moreover, the encapsulation and loading efficiency, in vitro release study, and ex-vivo antioxidant functionality of Cur-LNN on the stallion sperm preserved under cooled storage conditions were assessed. The fabricated Cur-LNN was spherical in shape and had an average particle size of 163.1 ± 1.8 nm, a zeta potential of -34.1 ± 1.9 mV, a poly-dispersity index of 0.339 ± 0.045, an encapsulation efficiency of 92.34 ± 0.18 %, and a loading efficiency of 35.57 ± 1.36 %. Ex-vivo evaluation revealed that supplementation of the semen extender with Cur-LNN has the potential to enhance sperm quality by improving total and progressive motility, plasma membrane functionality, and lipid peroxidation. These results demonstrate that Cur-LNN exhibited stronger antioxidant and protective effects than curcumin. Although further in vivo investigations are warranted, our ex-vivo results suggest that Cur-LNN has the potential to attenuate oxidative damage and can be used to fortify the antioxidant capacity of equine semen under cooled storage conditions.