The use of gold nanoparticles (AuNP) has been established in nanocarriers, diagnostics, and biosensors. Access to the targeted sites of these nanomaterials could directly involve the first line of defense, the innate immune system. Charges of nanomaterials play a critical role in a number of aspects such as stabilization, cellular uptake, modulation, and function of cells. Interactions and modulations of the charged nanomaterials against the innate immune system may occur even at very low concentration. To understand the effects of charges on monocyte behavior, in this study, the positively and negatively charged AuNP (AuNP+ve and AuNP-ve) of the similar size and shape on cytotoxicity, recognition, cellular behavior, and function were evaluated in vitro using U937 human monocyte cells as an innate immunity model. Both types of AuNP at various concentrations (0–5 nM) exhibited low toxicity. In addition, the cellular internalization of the AuNP+ve and AuNP-ve, as determined by TEM, occurred by different mechanisms, and the internalization had no effect on cellular destruction, as implied by the low levels of %LDH. Interestingly, the AuNP+ve recognition and internalization seemingly entered cells through receptor dependence and strongly affected cellular response to express both pro-inflammatory (IL-1β) and anti-inflammatory (TGF-β) cytokines, while the AuNP-ve stimulated TNF-α expression. Nevertheless, the AuNP-treated cells maintained normal function when exposed to planktonic bacteria. Thus, these results indicated that one part of the immune system interacted with different surface-charged AuNP, suggesting appropiate immunomodulation in biomedicine.

中文翻译：

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具有不同表面电荷的金纳米粒子对定位和单核细胞行为的影响。

金纳米颗粒（AuNP）的使用已在纳米载体，诊断和生物传感器中得到证实。进入这些纳米材料的目标部位可能直接涉及第一道防线，即先天免疫系统。纳米材料的电荷在许多方面起着至关重要的作用，例如稳定性，细胞摄取，调节和细胞功能。即使在非常低的浓度下，带电纳米材料对先天免疫系统的相互作用和调节也可能发生。为了了解电荷对单核细胞行为的影响，在这项研究中，在体外评估了大小和形状相似的带正电和带负电的AuNP（AuNP + ve和AuNP-ve）对细胞毒性，识别，细胞行为和功能的影响。使用U937人类单核细胞作为先天免疫模型。两种类型的不同浓度（0-5 nM）的AuNP都显示出低毒性。另外，通过TEM确定的AuNP + ve和AuNP-ve的细胞内在化是通过不同的机理发生的，并且内在化对细胞破坏没有影响，这是由低水平的％LDH所暗示的。有趣的是，AuNP + ve的识别和内在作用似乎是通过受体依赖性进入细胞的，并强烈影响细胞反应以表达促炎性（IL-1β）和抗炎性（TGF-β）细胞因子，而AuNP-ve刺激TNF-α α表达。然而，AuNP处理的细胞在暴露于浮游细菌时仍保持正常功能。因此，这些结果表明，免疫系统的一部分与不同表面带电的AuNP相互作用，