聚乙烯吡咯烷酮包覆的金纳米粒子抑制内皮细胞活力、增殖和 ERK1/2 磷酸化，并降低离体主动脉血管中内皮非依赖性舒张反应的幅度。

BACKGROUND: Gold nanoparticles (AuNPs) demonstrate clinical potential for drug delivery and imaging diagnostics. As AuNPs aggregate in physiological fluids, polymer-surface modifications are utilized to allow their stabilization and enhance their retention time in blood. However, the impact of AuNPs on blood vessel function remains poorly understood. In the present study, we investigated the effects of AuNPs and their stabilizers on endothelial cell (EC) and vasodilator function. MATERIALS AND METHODS: Citrate-stabilized AuNPs (12±3 nm) were synthesized and surface-modified using mercapto polyethylene glycol (mPEG) and polyvinylpyrrolidone (PVP) polymers. Their uptake by isolated ECs and whole vessels was visualized using transmission electron microscopy and quantified using inductively coupled plasma mass spectrometry. Their biological effects on EC proliferation, viability, apoptosis, and the ERK1/2-signaling pathway were determined using automated cell counting, flow cytometry, and Western blotting, respectively. Endothelial-dependent and independent vasodilator functions were assessed using isolated murine aortic vessel rings ex vivo. RESULTS: AuNPs were located in endothelial endosomes within 30 minutes' exposure, while their surface modification delayed this cellular uptake over time. After 24 hours' exposure, all AuNPs (including polymer-modified AuNPs) induced apoptosis and decreased cell viability/proliferation. These inhibitory effects were lost after 48 hours' exposure (except for the PVP-modified AuNPs). Furthermore, all AuNPs decreased acetylcholine (ACh)-induced phosphorylation of ERK1/2, a key signaling protein of cell function. mPEG-modified AuNPs had lower cytostatic effects than PVP-modified AuNPs. Citrate-stabilized AuNPs did not alter endothelial-dependent vasodilation induced by ACh, but attenuated endothelial-independent responses induced by sodium nitroprusside. PVP-modified AuNPs attenuated ACh-induced dilation, whereas mPEG-modified AuNPs did not, though this was dose-related. CONCLUSION: We demonstrated that mPEG-modified AuNPs at a therapeutic dosage showed lower cytostatic effects and were less detrimental to vasodilator function than PVP-modified AuNPs, indicating greater potential as agents for diagnostic imaging and therapy.

背景：金纳米粒子（AuNPs）在药物输送和成像诊断方面具有临床应用潜力。当 AuNPs 在生理流体中聚集时，会利用聚合物表面修饰来稳定它们，并延长它们在血液中的保留时间。然而，AuNPs 对血管功能的影响仍知之甚少。在本研究中，我们研究了 AuNPs 及其稳定剂对内皮细胞（EC）和血管舒张功能的影响。

材料和方法：合成了柠檬酸稳定的 AuNPs（12±3nm），并使用巯基聚乙二醇（mPEG）和聚乙烯吡咯烷酮（PVP）聚合物对其进行表面修饰。使用透射电子显微镜观察 AuNPs 被分离的 EC 和整个血管的摄取情况，并使用电感耦合等离子体质谱法进行定量。使用自动细胞计数、流式细胞术和 Western blot 分别确定它们对 EC 增殖、活力、凋亡和 ERK1/2 信号通路的生物学影响。使用离体小鼠主动脉血管环评估内皮依赖性和非依赖性血管舒张功能。

结果：AuNPs 在暴露 30 分钟内位于内皮内体中，而其表面修饰随时间推移延迟了这种细胞摄取。暴露 24 小时后，所有 AuNPs（包括聚合物修饰的 AuNPs）均诱导凋亡并降低细胞活力/增殖。暴露 48 小时后，除 PVP 修饰的 AuNPs 外，这些抑制作用消失。此外，所有 AuNPs 均降低了细胞功能的关键信号蛋白 ERK1/2 的乙酰胆碱（ACh）诱导磷酸化。mPEG 修饰的 AuNPs 的细胞抑制作用低于 PVP 修饰的 AuNPs。柠檬酸稳定的 AuNPs 不改变由 ACh 诱导的内皮依赖性血管舒张，但减弱了由硝普钠诱导的内皮非依赖性反应。PVP 修饰的 AuNPs 减弱了由 ACh 诱导的扩张，而 mPEG 修饰的 AuNPs 则没有，但这与剂量有关。

结论：我们证明，在治疗剂量下，mPEG 修饰的 AuNPs 表现出较低的细胞抑制作用，对血管舒张功能的损害小于 PVP 修饰的 AuNPs，这表明它们作为诊断成像和治疗剂具有更大的潜力。