Surface atomic arrangement of nanomaterials affects nanotoxicity

Understanding the roles of the properties of nanomaterials in biological interactions is a key issue in their safe applications, but the surface atomic arrangement, as an important property of engineered nanomaterials (ENMs), remains largely unknown. Herein, the interfacial interactions (affinity sites and intensity) between monolayer MoS₂ and zebrafish embryos mediated by 1 T phase surface atomic arrangement (octahedral coordination) and the 2H phase surface atomic arrangement (triangular prism coordination) MoS₂ nanosheets were studied. 1 T-MoS₂ first bound to phosphate and then proteins on the chorion, while the adhesion of 2H-MoS₂ occurred in the opposite order. The binding affinity of 2H-MoS₂ with embryos was higher than that of 1 T-MoS₂, and the former material changed the protein structure from β-sheets to turns and bends and random coils. Compared to 1 T-MoS₂, 2H-MoS₂ more readily entered embryos, which was facilitated by caveolae-mediated endocytosis, and caused higher developmental toxicity. Furthermore, metabolic pathways related to amino acid and protein biosynthesis and energy metabolism were affected by the nanomaterial surface atomic arrangements. The above results provide insights into the designs, applications and risk assessments of nanomaterials by the surface atomic arrangement regulation.