Hongzhe Sun

Silver nanoparticles (nano-Ag) are potent and broad-spectrum antimicrobial agents. In this study, spherical nano-Ag (average diameter = 9.3 nm) particles were synthesized using a borohydride reduction method and the mode of their antibacterial action against E. coli was investigated by proteomic approaches (2-DE and MS identification), conducted in parallel to analyses involving solutions of Ag(+) ions. The proteomic data revealed that a short exposure of E. coli cells to antibacterial concentrations of nano-Ag resulted in an accumulation of envelope protein precursors, indicative of the dissipation of proton motive force. Consistent with these proteomic findings, nano-Ag were shown to destabilize the outer membrane, collapse the plasma membrane potential and deplete the levels of intracellular ATP. The mode of action of nano-Ag was also found to be similar to that of Ag(+) ions (e.g., Dibrov, P. et al, Antimicrob. Agents Chemother. 2002, 46, 2668-2670); however, the effective concentrations of nano-Ag and Ag(+) ions were at nanomolar and micromolar levels, respectively. Nano-Ag appear to be an efficient physicochemical system conferring antimicrobial silver activities.

ADVERTISEMENT RETURN TO ISSUEPREVArticleTransferrin as a Metal Ion MediatorHongzhe Sun, Hongyan Li, and Peter J. SadlerView Author Information Department of Chemistry, University of Edinburgh, King's Buildings, West Mains Road, Edinburgh EH9 3JJ, U.K., and Department of Chemistry, the University of Hong Kong, Pokfulam Road, Hong Kong SAR, China Cite this: Chem. Rev. 1999, 99, 9, 2817–2842Publication Date (Web):August 21, 1999Publication History Received9 March 1999Revised14 June 1999Published online21 August 1999Published inissue 8 September 1999https://pubs.acs.org/doi/10.1021/cr980430whttps://doi.org/10.1021/cr980430wresearch-articleACS PublicationsCopyright © 1999 American Chemical SocietyRequest reuse permissionsArticle Views2565Altmetric-Citations332LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Anions,Ions,Iron,Metals,Receptors Get e-Alerts

Targeted drug delivery is an important research area in specific therapy. Transferrin-conjugated nanoparticles are an attractive formulation as a vehicle for specific cellular uptake and targeted drug delivery. In this report, atomic force microscopy imaging was used to visualize the process of cellular uptake of transferrin-coupled gold nanoparticles on the surfaces of live cells for the first time. High-resolution images were captured, showing the endocytosis of transferrin-conjugated nanoparticles taking place during the process of internalization. This specific transferrin-mediated nanoparticle uptake was validated by confocal scanning imaging and transferrin competition experiments.