Mapping technique for biodistribution of elements in a model organism, Caenorhabditis elegans, after exposure to copper nanoparticles with microbeam synchrotron radiation X-ray fluorescence

Abstract

To investigate the toxicological effects of nanomaterials, experimental studies on the absorption and accumulation in organisms are of broad interest. In the present study, Caenorhabditis elegans (C. elegans) was used as a ''model'' organism to investigate the bioaccumulation and toxicological effects of engineered copper nanoparticles with a scanning technique of microbeam synchrotron radiation X-ray fluorescence (m-SRXRF). The adult hermaphrodite is anatomically simple with 959 somatic cells and 1 mm in length. The mapping results of the whole organism indicate that the exposure to copper nanoparticles can result in an obvious elevation of Cu and K levels, and a change of bio-distribution of Cu in nematodes. Accumulation of Cu occurs in the head and at a location 1/3 of the way up the body from the tail compared to the un-exposed control. In contrast, a higher amount of Cu was detected in other portion of worm body, especially in its excretory cells and intestine when exposed to Cu 2+ . The results compared well with total Cu levels in nematodes, which were 4.10 AE 0.54, 12.32 AE 0.49 and 5.22 AE 0.63 mg g À1 dry weight for the PBS, Cu 2+ and Cu nanoparticle groups, respectively, measured by ICP-MS. The nondestructive and multi-elemental m-SRXRF provides an important tool for mapping the elemental distribution in the whole body of a single tiny nematode at lower levels.

3D imaging of transition metals in the zebrafish embryo by X-ray fluorescence microtomography

“…5 As SXRF microscopy operates in the hard X-ray energy regime, this technique can be employed to visualize the elemental content of thick hydrated tissues or small organisms such as nematodes 6 and zebrafish embryos 7 ; however, the resulting 2D maps correspond to projections of the integrated metal content along the excitation trajectory and thus fail to provide unambiguous insights into the actual 3D structural organization. Given the advances in X-ray imaging technology, notably the development of multi-element detectors with improved sensitivity, as well as detector electronics with fast readout, data acquisition times have been significantly shortened, thus enabling the visualization of the 3D elemental distributions based on tomographic projection series.…”

Copper ions influence the toxicity of β-amyloid(1–42) in a concentration-dependent manner in a Caenorhabditis elegans model of Alzheimer’s disease

“…We paid attention to the significant changes of expression patterns of some genes when the CL2006 worm was treated with CuCl 2 at concentrations between 10 −4 and 10 −3 mol L −1 . 16.2, were involved in the interaction and toxicity between Aβ1-42 and copper in a concentration-dependent manner in the CL2006 worm. In summary, the high expression levels of sod-1, prdx-2, and skn-1 genes are associated with the scavenging of ROS and ameliorating the paralysis behavior of the CL2006 worm, while high expression levels of hsp-60 and hsp-16.2 genes are related to increased ROS level and the deteriorating paralysis behavior of the CL2006 worm.…”

“…The spectra were analyzed by the AXIL program. The concentration was calculated by means of the normalization of the Compton scattering intensity [16].…”

Microanalytical investigation of nematodes

“…Gao et al [9] investigated the distribution of Cu, Ca, Fe, K, Mn, S, Zn in Caenorhabditis elegans after exposure to copper nanoparticles. The Microchemical Journal 105 (2012) 83-87 formation of lead biocrystals in nematodes was studied by electron microprobe analysis [10] and synchrotron based X-ray fluorescence spectrometry [11].…”