Development and characterization of a veterinary nanotechnological diluent based on essential oil
nanoemulsion for semen cryopreservation
Animal Reproduction; Nanotechnology; Sperm Cell
Semen cryopreservation is a crucial biotechnological tool for the preservation of genetic resources,
reduction of costs associated with the transport and maintenance of breeding animals, and mitigation
of the spread of sexually transmitted diseases. However, the freezing and thawing processes can
compromise sperm fertility due to cryoinjuries, which negatively impact post-thaw pregnancy rates.
To minimize such damage, the use of appropriate extenders, cryoprotectants, and species-specific
freezing protocols is essential. Cryopreservation is also associated with an imbalance in reactive
oxygen species (ROS), leading to oxidative stress, structural damage, and decreased fertilization
capacity. In this context, natural compounds with antioxidant properties—such as essential oils
(EOs)—represent a promising alternative to enhance sperm protection. When incorporated into
nanoemulsions, these compounds can achieve controlled release and reduce cytotoxicity, thereby
improving their efficacy during the cryopreservation process. Nanotechnology, particularly the use
of nanoemulsion-based delivery systems, has shown significant potential in veterinary medicine and
animal reproduction. Nanoemulsions, characterized by droplet sizes of up to 200 nm, improve the
bioavailability and absorption of active compounds, in addition to offering physicochemical stability
and controlled substance release. This study aimed to develop and evaluate a nanoemulsion
containing an antioxidant-rich essential oil, to be incorporated into a semen freezing extender for
breeding animals. The objective was to reduce sperm membrane damage, thereby improving motility
and fertilization potential post-thaw. As an innovative approach utilizing essential oil in a
conventional extender (Tris-egg yolk) for the cryopreservation of animal spermatozoa, this study is
expected to enhance sperm preservation outcomes, increase the average number of viable
insemination doses, and contribute to genetic improvement of livestock herds. In the broader
context, this advancement may support increased productivity in animal husbandry, job creation,
and income generation.