Overlooked Risks of Biochars: Persistent Free Radicals trigger Neurotoxicity in <i>Caenorhabditis elegans</i>

In recent years, biochars have gained increasing interest in mitigating climate changes and revitalizing contaminated or drained soil. Studies determining their impact on the ecosystem, especially on soil invertebrates, however, are still scarce and the neurotoxic potential of biochars has never been evaluated before. Using the model organism <i>Caenorhabditis elegans</i> we determined the neurotoxic effect of biochar produced from rice straw by pyrolysis at 500 °C at concentrations ranging from 0 to 2000 mg C·L^–1. Biochar had a hormetic effect on locomotion behavior. Furthermore, high concentrations impaired defecation as well as the recognition and response to a chemical attractant. None of the potential toxic chemicals in the biochar had sufficient high concentrations to explain the detected neurotoxic effect. Using electron paramagnetic resonance (EPR) spectroscopy, we detected free radicals in the biochar. Detrimental reaction of free radicals with biotic macromolecules can induce oxidative stress responses and are a potential reason for the evaluated neurotoxic effect of biochar. Overall, we were able to prove that biochars have the potential to act as weak neurotoxins to soil organisms and effects of persistent free radicals should be investigated further

Relationships between miRNA expression levels (means ± SD) and clinical characteristics of EC patients.

<p>Note:¹W =  whole saliva, S =  saliva supernatant; ²N/A  =  not available due to patients' refusal of further tests or treatments; meanwhile, some patients in stage IV could not undergo operations and resected tumors were not available, so the differentiation of the tumors in these patients could not be determined.</p

The bar charts of gTotalGeneSignal value of the six target miRNAs.

<p>A) With the exception of sample 4, the values of the six EC group samples were higher than those of the three healthy group samples. B) With the exception of sample 2, the values of the six EC group samples were higher than those of the three healthy group samples. C) With the exception of sample 10, the values of the seven EC group samples were higher than those of the two healthy group samples. D) With the exception of sample 10, the values of the seven EC group samples were higher than those of the two healthy group samples. E) All EC group values were lower than the three of the healthy group. F) Several studies have reported that miRNAs are aberrantly expressed in cancer tissue and plasma of EC patients; however, the gTotalGeneSignal value of miR-21 did not differ between the EC and healthy groups. However, it was also selected as a target miRNA.</p

Receiver operating characteristic curve analysis for esophageal cancer diagnosis.

<p>A) Whole saliva miR-10b*. B)whole saliva miR-144, and C) whole saliva miR-451. D)saliva supernatant miR-10b*. E)saliva supernatant miR-144. F)saliva supernatant miR-21. G) saliva supernatant miR-451.</p

Characteristics of EC patients and healthy controls.

<p>Note: 1. High temperature: >60°C. 2. According to the standard of mainland China, the definition of an alcoholic is as follows: male, ≥40 g/d; female, ≥20 g/d; consumption of alcohol (g)  =  volume of alcohol (mL) × concentration of alcohol (%) ×0.8.</p

Number of miRNAs detected in each sample.

<p>Note: EC, esophageal cancer; NC, normal control.</p

Bar charts of expression levels of aberrantly expressed miRNAs.

<p><b>A</b>) whole saliva miR-10b*. <b>B</b>) whole saliva miR-144. <b>C</b>) whole saliva miR-451. <b>D</b>) saliva supernatant miR-10b*. <b>E</b>) saliva supernatant miR-144. <b>F</b>) saliva supernatant miR-21. <b>G</b>) saliva supernatant miR-451. miRNA expression levels were calculated by the 2^−ΔΔCt method. These miRNAs were significantly upregulated in the EC (n = 39) compared with the healthy (n = 19) group.</p

Additional file 1: Figure S1. of Incorporation of a hinge domain improves the expansion of chimeric antigen receptor T cells

Hinge incorporation can promote the expansion of CAR T cells. Flow cytometric analysis of the percentage of 19.28z, 19-H.28z T cells, Meso.28z, Meso-H.28z T cells, PSCA.28z, PSCA-H.28z T cells, and GFP control T cells from day 6 to 15 during the in vitro culture period. The data are representative of independent experiments verified with cells from over three individual healthy human donors. (JPG 2876 kb