A Chinese research team recently revealed the combined multigenerational reproductive toxicity of Titanium dioxide nanoparticles (TiO₂ NPs) and cadmium in Caenorhabditis elegans.

This work was done by XU An and her colleagues with Institute of Technical Biology & Agriculture Engineering, Hefei Institutes of Physical Science.

TiO₂ NPs have an increasingly broad range of industrial and household applications, which brings more exposure to its emissions.

Unintentionally released TiO₂ NPs may interact with pre-existing heavy metal cadmium (Cd) in aquatic environments and eventually modify their behavior, fate, toxicity.

However, the influence of TiO₂ NPs on the multigenerational impairments caused by heavy metals is, to a large extend, unknown.

In XU's study, they investigated the combined multigenerational reproductive toxicity of TiO₂ NPs and Cd in Caenorhabditis elegans.

They found that TiO₂ NPs had strong adsorption and enriching ability towards Cd. Parental exposure to TiO₂ NPs at a non-toxic concentration promoted the reproductive toxicity of Cd not only in the C. elegans parental generation but also in their pollutant-free cultured F1 and F2 offspring.

TiO₂ NPs promoted the ingestion of Cd, while the lower pH environment in the gut accelerated desorption of Cd from TiO₂ NPs, leading to enhanced Cd bioaccumulation.

Using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), a in situ imaging technology, they found that TiO₂ NPs promoted the accumulation of Cd.

In addition, it was also found that TiO₂ NPs were mainly concentrated in the gut, pharyngeal pump, vulva, and anus.

However, a considerable amount of Cd was detected in other parts of C. elegans.

Their work further confirmed Cd gonad burden was increased by concurrent exposure to TiO₂ NPs, indicating the potential transfer of Cd to the next generation through germline.

Their study made novel exploration on the multigenerational toxicity of heavy metals associate with nanoparticles, and may provide new evidence of their transfer within germline.

This work was supported by Strategic Leading Science & Technology Program (B), National Natural Science Foundation of China, Major/Innovative Program of Development Foundation of Hefei Center for Physical Science and Technology and CASHIPS Director's Fund.

The multigenerational reproductive toxicity of co-exposure to TiO₂ NPs and Cd (Image by WANG Jingjing)