Carbon nanodots (CDs) are fluorescent nanomaterials that have attracted widespread attention for biomedical applications. Since different cells possess different membrane potentials, the influence of the trans-membrane potential on the adsorption behaviour needs to be explored extensively. It was found that fewer CDs can be adsorbed by depolarized cells with decreased membrane potential, as compared to hyperpolarized cells with enhanced membrane potential that promotes the adsorption of CDs. A similar adsorption trend was observed for two cell lines, namely NIH3T3 and MCF-7. Since phosphocholine is the primary component of the cellular membrane, the adsorption behaviour of CDs is further complemented by the interactions between CDs and three kinds of liposomes with different surface charges via the thermodynamic and kinetic perspectives. The adsorption constants between negatively charged CDs and liposomes are positively related to their membrane potential, which is similar to the adsorption rate constants. It was further found that the adsorption of CDs onto liposomes was initiated by electrostatic attraction forces. The membrane integrity and fluidity of liposomes exposed to CDs have also been characterized. The membrane potential of cells is, therefore, particularly important when predicting the relative cytotoxicity of CDs and developing CDs-based nanomaterials for biomedical applications.

中文翻译：

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细胞膜电势调节碳纳米点的吸附行为

碳纳米点（CDs）是荧光纳米材料，已在生物医学应用中引起广泛关注。由于不同的细胞具有不同的膜电位，因此跨膜电位对吸附行为的影响需要广泛研究。发现与具有增强的膜电位以促进CD的吸附的超极化细胞相比，具有减少的膜电位的去极化细胞可以吸附更少的CD。对于两种细胞系，即NIH3T3和MCF-7，观察到相似的吸附趋势。由于磷酸是细胞膜的主要成分，CD的吸附行为进一步由光盘和3种脂质体具有不同表面电荷之间的相互作用的补充通过热力学和动力学的观点。带负电荷的CD与脂质体之间的吸附常数与它们的膜电位正相关，这与吸附速率常数相似。进一步发现，CDs在脂质体上的吸附是由静电引力引起的。还已经表征了暴露于CD的脂质体的膜完整性和流动性。因此，在预测CD的相对细胞毒性并开发用于生物医学应用的基于CD的纳米材料时，细胞的膜电位特别重要。