These unique properties make the worm an important model system for biological research in many fields including not only genomics, cell biology, neuroscience and aging but also toxicity\cite{Hunt}. C. elegans model in biology is sorting the worms by age, and regarding their fast development rate, the experimenter needs to be highly trained to sort a consequent number of worms quickly by hand for a large statistic, and isolate groups for all the test conditions without biasing the experiment. Furthermore, in our study, the continuous worm feeding as well as the high-resolution imaging implicate manual removal of the worms from the incubator to the bench at each time point, which triggers temperature changes undesirable stress to the animal. To overcome this issue, we opted for a method using a microfluidics platform combined with optical microscopy to allow sorting, continuous feeding and imaging of the worms. Although many other researchers developed microfluidic tools to simplify C. elegans studies\cite{Charão_Souto_Brucker_Barth_Jornada_Ávila_Eifler-lima_Guterres_Pohlmann_Garcia_2015,Hanna_Cooksey_Dong_Nelson_Mao_Elliott_Petersen_2016,Jung_Qu_Aleman-meza_Wang_Riepe_Liu_Li_Zhong_2015,Kim_Lee_Cha_Hong_Chung_2017,Kim_Kwak_An_2013,Ma_Kabengi_Bertsch_Unrine_Glenn_Williams_2011,Mohan_Chen_Hsieh_Wu_2010,Rohde_Zeng_Gonzalez-rubio_Angel_Yanik_2007}, their approaches did not allow for a high-throughput screening. (Matteo/Laurent), please elaborate a bit the advantages, differences in respect to the method of Rhode et al etc.
Our system was developed at EPFL (Laboratory of Integrative Systems Physiology and Laboratory of Microsystems)(cite Cornaglia et al., 2015, 2016) HERE LAURENT AND MATTEO WILL EMPHASIZE.
We cultivated a wild type strain and used high-resolution optical microscopy to probe the changes in real-time. Contrary to the expectations, we found a stronger negative influence of the tin than of the lead compound on life span, development and fertility of C. elegans. Since in the community it is considered that toxicity studies of C. elegans results in predictive power for higher eukaryotes so these results are important for human exposure, as well. They underline the potential health hazards related to large-scale production of MAPbI3 and/or MASnI3, and invite the photovoltaic community to take safety measures and to amplify research on encapsulated systems to prevent the release of the materials into the environment.
Results
The following toxicity study was performed on the microfluidic platform on C. elegans by continuous injection of S-medium containing E. coli with or without perovskites during one week.