Document Type


Publication Date




Publication Title

ACS Nano








Real-time study of the transport and biocompatibility of nanomaterials in early embryonic development at single-nanoparticle resolution can offer new knowledge about the delivery and effects of nanomaterials in vivo, and provide new insights into molecular transport mechanisms in developing embryos. In this study, we directly characterized the transport of single silver nanoparticles into an in vivo model system (zebrafish embryos) and investigated their effects on early embryonic development at single-nanoparticle resolution in real time. We designed highly purified and stable (not aggregated and no photodecomposition) nanoparticles and developed single-nanoparticle optics and in vivo assays to enable the study. We found that single Ag nanoparticles (5- 46 nm) transport in and out of embryos through chorion pore canals (CPCs), and exhibit Brownian diffusion (not active transport), with ∼26 times lower diffusion coefficient (3×10-9 cm2/s) inside the chorionic space than that in egg water (7.7×10-8 cm2/s). In contrast, nanoparticles were trapped inside CPCs and the inner mass of the embryos, showing restricted diffusion. Individual Ag nanoparticles were observed inside embryos at each developmental stage and in normally developed, deformed, and dead zebrafish, showing that the biocompatibility and toxicity of Ag nanoparticles and types of abnormalities observed in zebrafish are highly dependent on the dose of Ag nanoparticles, with a critical concentration of 0.19 nM. Rates of passive diffusion and accumulation of nanoparticles in embryos are likely responsible for the dose-dependent abnormalities. Unlike other chemicals, single nanoparticles can be directly imaged inside developing embryos at nanometer (nm) spatial resolution, offering new opportunities to unravel the related pathways that lead to the abnormalities.


“This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Nano, copyright © 2007 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see

Original Publication Citation

Lee, K. J., Nallathamby, P. D., Browning, L. M., Osgood, C. J., & Nancy Xu, X. H. (2007). In vivo imaging of transport and biocompatibility of single silver nanoparticles in early development of zebrafish embryos. ACS Nano, 1(2), 133-143. doi:10.1021/nn700048y


0000-0001-5064-294X (Nallathamby, Prakash), 0000-0003-2231-5487 (Browning, Lauren), 0000-0002-7470-1948 (Xu, Xiao-Hong Nancy)