Layered double hydroxide (LDH) nanomaterials have recently become immense research area as it is used widely in industries. So, it’s chance of their release into natural environment and risk assessment to nontarget aquatic invertebrate increasing. So, the present study aimed to synthesize and confirm the crystalline formation of Co-Cd-Fe LDHs and Co-Cd-Fe/PbI₂ (LDH) and then to investigate the toxic impact of the two LDH on the adult freshwater snails (Biomphalaia alexandrina). Results showed that Co-Cd-Fe/PbI₂ LDH has more toxic effect to adult Biomphalaria than Co-Cd-Fe LDHs (LC₅₀ was 56.4 and 147.7 mg/L, 72 h of exposure, respectively). The effect of LC₂₅ (117.1 mg/L) of Co-Cd-Fe LDHs exposure on the embryo showed suppression of embryonic development and induced embryo malformation. Also, it showed alterations in the tegmental architectures of the mantle-foot region of B. alexandrina snails as declared in scanning electron micrograph. Also, exposure to this sublethal concentration caused abnormalities in hemocyte shapes and upregulated IL-2 level in soft tissue. In addition, it decreased levels of nonenzymatic reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), caspase-3 activity, and total protein content in significant manner. Glutathione S-transferase (GST) activity was not affected by LDH exposure. It caused histopathological damages in both glands of snails and also caused a genotoxic effect in their cells. The results from the present study indicated that LDH has risk assessment on aquatic B. alexandrina snails and that it can be used as a biological indicator of water pollution with LDH.

Graphical abstract

中文翻译：

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工程化层状双氢氧化物纳米材料在亚历山大生物指蜗中的作用机制和毒理学评价

层状双氢氧化物 (LDH) 纳米材料最近已成为巨大的研究领域，因为它在工业中得到广泛应用。因此，它们释放到自然环境中的机会和对非目标水生无脊椎动物的风险评估增加了。因此，本研究旨在合成并确认 Co-Cd-Fe LDHs 和 Co-Cd-Fe/PbI ₂ (LDH) 的结晶形成，然后研究这两种 LDH 对成年淡水蜗牛 ( Biomphalaia ) 的毒性影响亚历山德丽娜）。结果表明，Co-Cd-Fe/PbI ₂ LDH比Co-Cd-Fe LDHs对成虫有更大的毒性作用（LC ₅₀分别为56.4 和147.7 mg/L，暴露72 h）。_{LC 25}的作用(117.1 mg/L) Co-Cd-Fe LDHs 暴露在胚胎上显示抑制胚胎发育和诱导胚胎畸形。此外，它还显示了B. alexandrina地幔足区域的被盖结构的变化扫描电子显微照片中显示的蜗牛。此外，暴露于这种亚致死浓度会导致血细胞形状异常并上调软组织中的 IL-2 水平。此外，它还能显着降低非酶促还原型谷胱甘肽 (GSH)、过氧化氢酶 (CAT)、超氧化物歧化酶 (SOD)、caspase-3 活性和总蛋白质含量。谷胱甘肽 S-转移酶 (GST) 活性不受 LDH 暴露的影响。它对蜗牛的两个腺体造成组织病理学损伤，并对它们的细胞造成遗传毒性作用。本研究结果表明，LDH对水生亚历山大螺具有风险评估作用，可作为LDH水体污染的生物指标。

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