The In Vivo Evaluation of PbS Nanoparticle-Based Solution on Avian Embryo as an Animal Model

Lead sulfide nanoparticles (PbS NPs) are promising materials for biomedical imaging. However, their safety during embryonic development remains inadequately explored. This study investigated for the first time the developmental toxicity, hepatic effects, angiogenic activity, and irritation potential of PbS NPs using the Chick Embryotoxicity Screening Test (CHEST) and the chorioallantoic membrane (CAM) assay. Fertilized chicken eggs were exposed to various concentrations of PbS NPs (6%, 10%, 12%, 20%, 25%, 50%, and 100%). Developmental toxicity was assessed by mortality rate, body and selected organ weights, malformations, liver histological alterations, and RT-qPCR of antioxidant-related genes. Vascular evaluation was quantitatively assessed using the CAM assay with the following irritation potential analysis. Embryonic exposure to PbS NPs resulted in concentration-dependent developmental effects, with embryo mortality reaching 56% at the highest concentration and the presence of developmental malformations in surviving embryos. No histological alterations were observed in the liver; however, higher concentrations altered α-smooth muscle actin and cell proliferation activity and modulated antioxidant gene expression. In the CAM assay, the highest concentrations of PbS NPs significantly reduced total vessel area, branching, and total vessel length while inducing only slight irritation, characterized by vascular dilatation. These findings demonstrate concentration-dependent developmental and vascular responses following direct embryonic exposure to PbS NPs under the experimental conditions. Only the highest concentrations caused significant morphological, angiogenic, and molecular alterations after short-time PbS NP exposure. This study provides a comprehensive safety evaluation of PbS NPs during chicken embryonic development and supports their potential for further investigation in biomedical imaging. Further, it indicates that the combination of CHEST and CAM assays as complementary models can be used for preclinical developmental nanotoxicity assessment.