Mitochondria, as multifunctional and partially independent structures, play a crucial role in determining essential life processes. Recently, their significance in reproductive biology has gained increasing attention. This review aims to comprehensively analyse the role of mitochondrial processes in oocyte maturation and embryo culture. A comprehensive literature review was conducted to highlight the importance of mitochondrial activity in the early stages of life formation. Proper mitochondrial function provides energy, maintains genomic stability, and ensures optimal conditions for fertilisation and embryo progression. Understanding these processes is essential to optimise culture conditions and identify new mitochondrial biomarkers that improve reproductive success and improve assisted reproductive technologies (ARTs). Enhancing mitochondrial function in female reproductive cells is the key to improving oocyte and embryo quality, which can lead to better in vitro fertilisation and embryo transfer. Furthermore, advances in diagnostic techniques, such as mitochondrial genome sequencing, offer a more precise understanding of the relationship between mitochondrial health and oocyte quality. However, fully understanding mitochondrial functions is only part of the challenge. Expanding knowledge of the interactions between mitochondria and other cellular structures is crucial for future advancements in reproductive medicine. Understanding these complex relationships will provide deeper insight into improving reproductive outcomes and embryo development.

Nanotechnology, based on nanoparticles, has become an emerging interdisciplinary tool in reproductive biotechnology, offering innovative opportunities to improve fertilization efficiency and reproductive performance in farm animals. The purpose of this review is to provide an updated synthesis of current research on nanoparticle-based approaches that enhance in vitro fertilization outcomes and other assisted reproductive technologies. The focus is on the biological mechanisms, potential benefits, and limitations of nanoparticle use in animal reproduction. Nanoparticles—including gold, silver, zinc oxide, selenium, and magnetic iron oxide—exhibit distinctive physicochemical properties that enable targeted interactions with gametes and reproductive cells. When used in semen extenders or culture media, nanoparticles improve sperm motility, acrosome and membrane integrity, and reduce oxidative stress and apoptosis. These effects contribute to enhanced fertilization rates and higher embryo developmental competence. In addition, nanoparticles can function as carriers for hormones, antioxidants, and growth factors, stabilizing reagents essential for oocyte maturation, sperm capacitation, and early embryo culture. The review also discusses nanopurification (selectively isolating and removing particles) and nanosorting (separating or organizing nanoscale objects) techniques that allow for non-invasive selection of viable gametes, and fluorescence- and magnet-assisted sorting systems that increase precision in sperm sexing. The mechanical aspects of nanoparticle–cell interactions are analyzed, emphasizing the influence of particle size, dose, and surface modification on both biological efficacy and cytotoxicity. Safety, toxicological concerns, and regulatory frameworks—including International Organization for Standardization (ISO) standards and European Commission recommendations—are critically reviewed to highlight the need for harmonized biocompatibility criteria. Although nanoparticle use in animal reproduction remains largely experimental, accumulated evidence demonstrates its potential to improve reproductive efficiency and reduce economic losses. Integrating nanoparticle-based systems with existing reproduction platforms may represent a transformative step toward sustainable and precision-driven livestock breeding.

Paternal contributions to preimplantation embryo development are increasingly recognized as an important component of reproductive success, but the associations between male reproductive phenotype, early embryonic competence, and embryo molecular characteristics remain insufficiently defined. Using bovine in vitro embryo production as a translational large-mammalian model, this study evaluated whether paternal reproductive phenotype and oocyte origin were associated with embryo developmental performance and embryonic sirtuin expression. Oocytes obtained from mature cows or heifers were fertilized with semen from bulls differing in reproductive status, including bulls characterized by libido disturbances and irregular semen collection. Fertilization, cleavage, blastocyst formation, and hatching were assessed, while embryonic SIRT2, SIRT3, SIRT6, and SIRT7 expression was quantified by immunofluorescence. Early developmental endpoints were relatively preserved, whereas differences were more evident at later stages of preimplantation development. Cow-derived oocytes were associated with higher hatching rates than heifer-derived oocytes. Embryos generated using semen from bulls with an impaired reproductive phenotype showed lower developmental competence and lower SIRT6 and SIRT7 expression. SIRT6 expression showed the strongest positive correlation with hatching, and positive correlations were also observed among the analyzed sirtuins. These findings indicate that paternal reproductive phenotype and oocyte origin are associated with bovine embryo developmental competence and embryonic sirtuin profiles. Embryonic SIRT6 and SIRT7 expression may represent candidate molecular indicators of embryo competence; however, causal relationships cannot be inferred from the present study design.