Nuclear penetration of surface functionalized gold nanoparticles

Yan Juan Gu, Jinping Cheng, Chun Chi Lin, Yun Wah Lam, Shuk Han Cheng, Wing Tak Wong

Research output: Contribution to journalArticlepeer-review

184 Citations (Scopus)


Free gold nanoparticles easily aggregate when the environment conditions change. Here, gold nanoparticles (AuNPs) with average diameter of 3.7 nm were prepared and then modified with poly(ethylene glycol) (PEG) to improve stability. The gold nanoparticles were first surface-modified with 3-mercaptopropionic acid (MPA) to form a self-assembled monolayer and subsequently conjugated with NH2-PEG-NH2 through amidation between the amine end groups on PEG and the carboxylic acid groups on the particles. The biocompatibility and intracellular fate of PEG-modified gold nanoparticles (AuNP@MPA-PEG) were then studied in human cervical cancer (HeLa) cells. Cell viability test showed that AuNP@MPA-PEG did not induce obvious cytotoxicity. Both confocal laser scanning microscopy and transmission electron microscopy demonstrated that AuNP@MPA-PEG entered into mammalian cells and the cellular uptake of AuNP@MPA-PEG was time-dependent. Inductively coupled plasma mass spectrometry and confocal microscopy imaging further demonstrated that AuNP@MPA-PEG penetrated into the nucleus of mammalian cells upon exposure for 24 h. These results suggest that surface modification can enhance the stability and improve the biocompatibility. This study also indicates that AuNP@MPA-PEG can be used as potential nuclear targeted drug delivery carrier.

Original languageEnglish
Pages (from-to)196-204
Number of pages9
JournalToxicology and Applied Pharmacology
Issue number2
Early online date27 Mar 2009
Publication statusPublished - 1 Jun 2009
Externally publishedYes

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