Abstract: Objective: To investigate the effect of nanoscale zirconium-porphyrin metal-organic framework (NPMOF) on the development of nervous system in larval zebrafish. Methods: Embryos of zebrafish were incubated to E3 medium (n=500) or 100 mg/L NPMOF-E3 medium (n=500) from 6 hours post fertilization (hpf) to 28, 48, 72, 96 or 120 hpf. At 28, 48, 72, 96 and 120 hpf, 60 fish were collected respectively for quantitative real-time PCR in both groups. At 120 hpf, 20 fish were used for in situ hybridization, 150 fish were used for immunofluorescence and 30 fish were used for behavioral test, respectively. The shape and size of NPMOF was measured by TEM, and the optical properties were detected by UV-Vis and Fluorescence Spectrometer. In vivo development of multiple neurocytes was examined via in situ hybridization, immunofluorescence and quantitative real-time PCR. Behavioral test was used to manifest the locomotor changes of larval zebrafish. Results: Compared to control group, the mRNA expression levels of neurodevelopment-relative, neuron-relative and neuroglia-relative genes were partially increased obviously after NPMOF exposure (P＜ 0.05). The distribution and phenotype of neurons and oligodendrocytes showed no significant differences between exposed and unexposed groups, while exposed group showed an increase in the number of müller glia and astrocytes (P＜0.05). In behavioral test, there was an increase in total movement distance, fast movement time and velocity and a decrease in total rest time following NPMOF exposure (P＜0.05). Conclusion: The data indicate the potential facilitating effect of 100 mg/L NPMOF on neurodevelopment in vivo, especially on the growth of müller glia and astrocytes.

Key words: nanoscale zirconium-porphyrin metal-organic framework, neurodevelopment, central nervous system, retina, zebrafish