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Surface Modification of Cisplatin-Complexed Gold Nanoparticles and Its Influence on Colloidal Stability, Drug Loading, and Drug Release



Jiaojie Tan, Tae Joon Cho, De-Hao Tsai, Jingyu Liu, John M. Pettibone, Rian You, Michael R. Zachariah, Vincent A. Hackley


Cisplatin-complexed gold nanoparticles (PtII-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, polyethylene glycol (PEG) stabilized cisplatin-complexed AuNPs were synthesized as a model anti-tumor drug platform, where cisplatin (PtII) is attached via a dendrimer-like ligand. Surface modification and its influence on drug loading, colloidal stability and drug release were assessed. We show that upon complexation of PtII, colloidal stability decreases, but PEGylated AuNP conjugates (PtII-AuNP-dendron-SH-PEG) exhibit enhanced dispersion stability with an insignificant trade-off in drug loading capacity - compared with the non-PEGylated control. 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 loading was examined using a novel, previously described electrospray differential mobility analyzer (ES-DMA) hyphenated with an inductively coupled plasma mass spectrometer (ICP-MS). Using ES-DMA-ICP-MS, AuNP conjugates were size- classified based on their electrical mobility, while PtII loading was simultaneously quantified by determination of Pt mass. Colloidal stability was quantitatively evaluated in biologically relevant media by ES-DMA-ICP-MS. Finally, PtII release performance was evaluated, and exhibited a clear pH dependence. Relative molecular mass of the PEG had no significant influence on PtII uptake or release performance, while PEGylation substantially improved the colloidal stability of the conjugate.


drug delivery, cisplatin, gold nanoparticle, stability, drug loading, release, DMA, ICP-MS


Tan, J. , Cho, T. , Tsai, D. , Liu, J. , Pettibone, J. , You, R. , Zachariah, M. and Hackley, V. (2017), Surface Modification of Cisplatin-Complexed Gold Nanoparticles and Its Influence on Colloidal Stability, Drug Loading, and Drug Release, Langmuir, [online],, (Accessed April 14, 2024)
Created November 9, 2017, Updated October 12, 2021