Nano Graphene oxide (nGO) is a nanomaterial synthesized by chemically exfoliating graphite oxide, exhibiting unique physical, chemical, and mechanical properties. In recent years, nGO has garnered increasing attention in the fields of agriculture and food science. In agriculture, nGO serves as an effective pesticide carrier, enhancing formulation stability and enabling controlled release mechanisms that reduce dosage requirements while mitigating environmental contamination. Furthermore, nGO enhances soil physicochemical properties through improved water retention and nutrient retention capacity, thereby promoting plant growth and seed germination via microenvironment modulation. In food science, its inherent antibacterial activity and structural robustness render nGO suitable for advanced packaging systems to prolong shelf life. Additionally, the material's conductive and fluorescent properties facilitate the development of ultrasensitive biosensors for detecting contaminants such as heavy metals and microbial pathogens. Despite these advancements, rigorous safety evaluations remain imperative to assess the long-term impacts of nGO on human health and ecological systems.

Infertility represents a significant global public health challenge, approximately 17.5% of adults will experience infertility at some point in their lives. Environmental pollution is recognized as a key risk factor for infertility. Some studies have found that chemical substances in the environment, such as pesticides, chemicals in plastics (such as bisphenol A and phthalates), heavy metals, and air pollutants, may have adverse effects on the reproductive system. Despite these observations, mechanistic insights into pollutant-induced reproductive impairments remain insufficient, necessitating comprehensive investigations to develop targeted prevention strategies. This includes not only reducing the emission and exposure to these pollutants but also raising public awareness about the potential impacts of environmental pollution on reproductive health. In-depth investigation into the effects of environmental pollutants on reproductive health is of paramount importance for improving global fertility rates and enhancing public health outcomes.

Graphene-family nanomaterials (GFNs) have attracted significant interest owing to their versatile applications in biomedicine [26]. NGO, as a type of engineered carbon nanomaterial (CNM), has emerged as one of the most promising nanomaterials since its isolation in 2004 [15]. This type of nanomaterial has a particular surface area [18], excellent flexibility [21], high mechanical strength [17], and ease of surface functionalization (Y. [28]), making it a popular choice in electrocatalysis, electrode material, sensors, sorbents, and biological delivery [4]. The escalating global production of nGO, driven by its widespread adoption, has raised concerns regarding its potential environmental dispersion into hydrosphere, soil, atmosphere, biosphere, and human systems [1]. Unlike other carbon nanotubes and graphene, nGO possesses a wealth of hydrophilic surface oxygen functional groups. These functional groups significantly enhance nGO's affinity for polar solvents, enabling it to form stable suspensions in water and other solvents [7]. Additionally, these surface functional groups endow nGO with unique chemical reactivity, making it highly applicable in various fields such as biomedicine, environmental remediation, and composite materials [11]. Despite these advantages, the high dispersibility and stability of nGO heighten its potential risks to microbial and mammalian systems. While such nanomaterials deliver significant economic benefits, their proliferation necessitates rigorous evaluation of associated environmental and health hazards. Currently, the research on nGO is still in its nascent phase, necessitating further exploration and validation to understand its precise health implications.

Previous research indicates that the extensive production of nGO inevitably increases human exposure to it through various routes such as skin contact, inhalation, and ingestion [6]. This exposure has been associated with cytotoxicity, genotoxicity, and organ toxicity, attributed to nGO's ability to damage cell membranes through extraction and cleavage processes (L. [2]). Research has demonstrated the potential for nGO to be transferred through the food chain, leading to its accumulation within cells of humans or animals. Subsequently, it distributes to various tissues and organs including the kidney, spleen, liver, lungs, among others. Additionally, recent investigations have identified nGO as a contaminant associated with reproductive toxicity [22]. The negative impacts have been demonstrated in zebrafish [1], Oryzias latipes [5], mice [25], humans (A. [23]), and other species [27]. Histological evidence shows nGO accumulation in Oryzias latipes gonads causes fertilized egg abnormalities and mortality [5]. In vitro experiments conducted by Wang revealed that treatment with nGO induced significant production of reactive oxygen species (ROS) in cells, exhibiting higher toxicity than other graphene derivatives (A. [23]). Singh confirmed that the exceptionally flat surface of nGO could intercalate into the DNA helix and disrupt physiological processes such as DNA damage repair and apoptosis [20]. Chen et al. demonstrated that exposure to nGO can induce cell differentiation and apoptosis through modulation of phosphorylation levels of proteins upstream and downstream of the ERK pathway (Y. [3]), which is an important protein kinase of the MAPK cascade [12]. Oral administration of nGO to maternal mice resulted in developmental delays in their offspring, including reduced weight and shortened body length [25]. Notably, studies revealed that graphene oxide (GO) disrupts cell cycle progression, while nGO impairs cell viability via apoptosis and DNA degradation (Hashemi et al., 2020), underscoring the necessity to investigate mitochondrial dysfunction, oxidative stress, and cytoskeletal dynamics, which are key parameters directly linked to oocyte developmental competence and genomic stability. Furthermore, exposure to graphene oxide nanoparticles (GO NPs) during critical windows of gametogenesis-namely, early germ cell differentiation and the gametogenesis stage in adulthood-induces inheritable reproductive toxicity in medaka (Oryzias latipes) [13], highlighting the urgency to elucidate its acute effects on oocyte quality and fertilization potential. While previous studies have reported on the reproductive toxicity induced by nGO, there remains a significant gap in our understanding regarding its effects and potential mechanisms on oocyte quality, particularly in terms of oocyte developmental competence.

In this study, we used porcine oocytes to explore the molecular mechanisms by which nGO impairs oocyte quality, aiming to reveal pathways associated with mitochondrial dysfunction, oxidative stress, and early apoptosis in oocytes. These findings contribute to our understanding of nGO-induced female gamete toxicity, particularly regarding oocyte quality.