Ionic liquids (ILs), owing to their low vapor pressure and excellent solvating ability, are being increasingly applied in various industries to replace highly toxic organic solvents. They mainly pollute aquatic environment and soils, directly endangering eco-environment and human health. Therefore, it is critical to understand and optimize structural motifs of ILs with reduced toxicity. Considering human oral exposure is the major route, our investigations employed a human cell panel (modeling oral exposures) including human stomach (GES-1), intestinal (FHC), liver (HepG2) and kidney (HEK293) cells using a series of experimental and computational approaches to explore the cytotoxicity and molecular mechanism of ILs. We discovered that the cytotoxicity of triazolium and imidazolium ILs was human cell line-dependent with cytotoxicity in an order of FHC > GES-1 > HepG2 > HEK293. For this reason, a toxicity assay using a single cell line was highly inappropriate. Compared to anions (Br^-, OTs^-, OTMBS^-) we tested, the cation of ILs played a major role in causing cytotoxicity. Ionic liquids with cations having longer hydrophobic sidechains (IL09 vs. IL01) readily insert into cell membranes with enhanced membrane and lipidomic perturbations, induce cytotoxicity by triggering cell cycle arrest and apoptosis. Reducing sidechain length and incorporating three nitrogen atoms (triazolium) instead of two (imidazolium) in the cation core alleviated cytotoxicity by reducing cell membrane perturbations and cell function interference. These findings provide important guiding principles for the design of the next-generation of “green” and safe ILs.

离子液体（ILs）由于其低蒸气压和优异的溶解能力，越来越多地应用于各个行业以替代剧毒有机溶剂。它们主要污染水环境和土壤，直接危害生态环境和人体健康。因此，了解和优化具有降低毒性的 IL 的结构基序至关重要。考虑到人体经口暴露是主要途径，我们的研究采用了一个人体细胞组（模拟口腔暴露），包括人胃 (GES-1)、肠 (FHC)、肝 (HepG2) 和肾 (HEK293) 细胞，使用了一系列实验和计算方法来探索 ILs 的细胞毒性和分子机制。我们发现三唑鎓和咪唑鎓 ILs 的细胞毒性是人类细胞系依赖性的，细胞毒性的顺序为 FHC > GES-1 > HepG2 > HEK293。出于这个原因，使用单个细胞系的毒性测定是非常不合适的。与阴离子（Br^- , OTs ^- , OTMBS ^- ) 我们测试了，ILs 的阳离子在引起细胞毒性中起主要作用。具有较长疏水侧链的阳离子（IL09与IL01）的离子液体很容易插入细胞膜，增强细胞膜和脂质组学的扰动，通过触发细胞周期停滞和细胞凋亡来诱导细胞毒性。减少侧链长度并在阳离子核心中加入三个氮原子（三唑鎓）而不是两个（咪唑鎓）通过减少细胞膜扰动和细胞功能干扰来减轻细胞毒性。这些发现为下一代“绿色”和安全 IL 的设计提供了重要的指导原则。