Effects of ZIF-8 Nanoparticles on the Survival, Development, and Locomotor Activity of Early-life-stages of Zebrafish (Danio rerio)

Zeolite imidazolate framework-8 (ZIF-8) is a class of metal-organic frameworks, which have various applications in drug delivery, water pollution remediation, gas storage, and so on. However, little is known about its ecotoxicity to aquatic organisms. In the present study, the effects of ZIF-8 nanoparticles (NPs) on the survival, development, and behavioral traits of early-life stages (0-120 hpf) of zebrafish (Danio rerio) were evaluated. Results showed that the survival of zebrafish embryos was negatively associated with the exposure concentration of ZIF-8 NPs, and the 96-h LC50 (ranges) for ZIF-8 NPs to zebrafish embryos was 642.9 (483.3-915.2) mg/L. Exposure to ZIF-8 NPs at 90 and 900 mg/L significantly delayed the hatching time of zebrafish embryos. Besides, the heart rates of embryos exposed to ZIF-8 NPs at 0.9, 9.0, and 90 mg/L declined significantly at 72 hpf (larvae), but not at 48 hpf (embryo). Moreover, exposure to ZIF-8 NPs at 9.0 mg/L induced hyperactive effects on newly hatched zebrafish, as indicated by significantly higher average swimming speed and spent more time at high mobility status.