Developmental toxicity assessment of molybdenum titanium carbide MXene using zebrafish embryo and larvae model

MXenes are two-dimensional (2D) transition metal carbides and nitrides with promising applications in biomedicine, drug delivery, and tissue engineering. However, their information regarding the developmental safety in aquatic organisms remains limited. In this study, we have evaluated the developmental toxicity of molybdenum titanium carbide (Mo₂TiC₂) MXene in the zebrafish embryo and larval model. The fertilized embryos were segregated after breeding and were exposed to Mo₂TiC₂ MXene at 10, 20, 40, 80, and 160 μg/mL concentrations in E3 medium. After exposure, they were monitored up to 96 h post-fertilization (hpf). The developmental endpoints like hatching rate, survival rate, morphological abnormalities, and heart rate, were evaluated during the exposure period. At all the tested concentrations, no significant mortality and major developmental malformations were observed, indicating the absence of acute developmental toxicity under the experimental conditions. However, a slight delay in embryo hatching and significant reduction in heart rate was observed at higher exposure concentrations (160 μg/mL). These findings indicate that while higher concentrations cause minor-sublethal variations, Mo₂TiC₂ MXene exhibits low developmental toxicity in zebrafish embryos within the tested concentration range. This study provides preliminary evidence supporting the developmental biosafety profile of Mo₂TiC₂ MXene and contributes to the growing understanding of the environmental safety of emerging MXene nanomaterials. Further studies on chronic exposure, biodistribution, oxidative stress and molecular mechanisms are required to completely evaluate the developmental toxicity and environmental risk of Mo₂TiC₂ MXene.