Cisplatin-complexed gold nanoparticles (Pt^II–AuNP) provide a promising strategy for chemo-radiation-based anticancer drugs. Effective design of such platforms necessitates reliable assessment of surface engineering on a quantitative basis and its influence on drug payload, stability, and release. In this paper, poly(ethylene glycol) (PEG)-stabilized Pt^II–AuNP was synthesized as a model antitumor drug platform, where Pt^II is attached via a carboxyl-terminated dendron ligand. Surface modification by PEG and its influence on drug loading, colloidal stability, and drug release were assessed. Complexation with Pt^II significantly degrades colloidal stability of the conjugate; however, PEGylation provides substantial improvement of stability in conjunction with an insignificant trade-off in drug loading capacity compared with the non-PEGylated control (<20% decrease in loading capacity). In this context, the effect of varying PEG concentration and molar mass was investigated. On a quantitative basis, the extent of PEGylation was characterized and its influence on dispersion stability and drug load was examined using electrospray differential mobility analysis (ES-DMA) hyphenated with inductively coupled plasma mass spectrometry (ICP-MS) and compared with attenuated total reflectance–FTIR. Using ES-DMA-ICP-MS, AuNP conjugates were size-classified based on their electrical mobility, while Pt^II loading was simultaneously quantified by determination of Pt mass. Colloidal stability was quantitatively evaluated in biologically relevant media. Finally, the pH-dependent Pt^II release performance was evaluated. We observed 9% and 16% Pt^II release at drug loadings of 0.5 and 1.9 Pt^II/nm², respectively. The relative molar mass of PEG had no significant influence on Pt^II uptake or release performance, while PEGylation substantially improved the colloidal stability of the conjugate. Notably, the Pt^II release over 10 days (examined at 0.5 Pt^II/nm² drug loading) remained constant for non-PEGylated, 1K-PEGylated, and 5K-PEGylated conjugates.

中文翻译：

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顺铂复合金纳米粒子的表面修饰及其对胶体稳定性，载药量和药物释放的影响

顺铂复合金纳米颗粒（Pt ^II –AuNP）为基于化学辐射的抗癌药物提供了一种有前途的策略。这种平台的有效设计需要对表面工程进行定量的可靠评估，以及其对药物有效载荷，稳定性和释放的影响。在本文中，合成了聚乙二醇（PEG）稳定的Pt ^II –AuNP作为模型抗肿瘤药物平台，其中Pt ^II通过羧基末端的树枝状配体连接。评估了PEG的表面修饰及其对载药量，胶体稳定性和药物释放的影响。与Pt ^II络合显着降低缀合物的胶体稳定性；然而，与非聚乙二醇化的对照相比，聚乙二醇化可显着提高稳定性，同时药物载量也可以忽略不计（载量下降<20％）。在这种情况下，研究了改变PEG浓度和摩尔质量的影响。在定量基础上，表征了PEG化的程度，并使用电喷雾差分迁移率分析（ES-DMA）和电感耦合等离子体质谱（ICP-MS）进行了联用，研究了PEG化程度对分散稳定性和载药量的影响，并将其与衰减的全反射率进行了比较–FTIR。使用ES-DMA-ICP-MS，AuNP共轭物基于其电迁移率进行了大小分类，而Pt ^II通过测定Pt质量同时定量负载。在生物学相关介质中定量评估胶体稳定性。最后，评估了pH依赖性Pt ^II释放性能。我们观察到分别在0.5和1.9 Pt ^II / nm ^2的载药量下释放了9％和16％的Pt ^II。PEG的相对摩尔质量对Pt ^II的摄取或释放性能没有显着影响，而PEG化大大改善了缀合物的胶体稳定性。值得注意的是，Pt ^II释放了10天（以0.5 Pt ^II / nm ^2检查 对于非聚乙二醇化，1K聚乙二醇化和5K聚乙二醇化的缀合物，药物负载量保持恒定。