On the Use of Solid Lipid Nanoparticles for Delivering Lavender Hydroalcoholic Extract as an Antioxidant to NMRI Mice Spermatozoa During Handling, Cryopreservation, and Thawing.

Purpose: This study investigated the cryoprotective and antioxidant effects of lavender hydroalcoholic extract-loaded solid lipid nanoparticle (LHE-SLN) during handling, freezing, and thawing of NMRI mouse sperm. Methods: LHE-SLNs were synthesized using the self-assembly method. After evaluating their physicochemical characteristics, NMRI mouse sperm were exposed to four concentrations (1.5, 3, 4.5 and 10 μg/mL) of LHE-SLN in handling, freezing and post-thaw incubation. After each step, sperm viability, motility and DNA fragmentation were assessed. The activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), as well as the levels of nitric oxide (NO), were measured. The gene expression of Results: The nanoparticles were spherical, with an average size of 235.8 ± 11.06 nm and a zeta potential of -21.7 ± 5.35 mV. All experiments showed increased cell viability and motility, reduced DNA fragmentation, and elevated NO levels. The activity of SOD, CAT, and GPX was significantly enhanced. Additionally, antioxidant genes were upregulated, while pro-apoptotic genes were downregulated. Conclusion: These findings suggest that LHE-SLNs, particularly at 1.5 μg/mL, can effectively reduce oxidative stress, potentially enhancing sperm preservation outcomes through sustained delivery of antioxidants.