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Inhibition of cell-associated HIV-1 by silver nanoparticles


The glycoprotein gp120 and gp41 of HIV are the main targets for neutralizing antibodies (NABs). It appears that silver nanoparticles (AgNPs) also inhibit HIV-1 targeting same glycoproteins. In this study, we demonstrated that silver nanoparticles are efficient in neutralizing HIV-1 at non toxic concentrations. We also found an additive effect between the four NABs and AgNPs when combined against cell-associated HIV-1 infection in vitro.

Materials and methods

The HIV-1IIIB virus, U373-MAGI-CXCR4CEM, HTLV-IIIB, Monoclonal antibody to HIV-1 gp41 (126-7), HIV-1 gp120 Antiserum (PB1 Sub 2), HIV-1 gp120 Antiserum (PB1), and HIV-1 gp120 Monoclonal Antibody (F425 B4e8) were obtained from the NIH AIDS Research and Reference Reagent Program, Division of AIDS, NIAID. The silver nanoparticles coated with 0.2 wt% PVP were obtained from Nanoamor, Houston, TX. Stock solutions and serial dilution of AGNPs were prepared in RPMI 1640 cell culture media. Cytotoxicity of AgNPs was ascertained in U373-MAGI-CXCR4CEM cells. The cell viability was assessed using a CellTiter-Glo® Luminescent Cell Viability Assay and Glomax Multidirection System (Promega). The neutralizing activity of AgNPs and NABs against HIVIIIB cell-free and cell associated virus was evaluated in an assay involving U373-MAGI-CXCR4CEM cells, AgNPs and NABs. Assessment of HIV-1 infection was performed with the Beta-Glo Assay System using Glomax Multidirection System (Promega). The percentage of residual infectivity after NABs, AgNPs, NABS+AgNPs, or media was calculated with respect to the positive control. The 50% inhibitory concentration (IC50) was defined according to the percentage of infectivity inhibition relative to the positive control. The inhibition data was statistically analyzed with the help of Wilcoxon rank-sum (Wilcoxon-Mann-Whitney test) test.


The four NABs used in the study inhibited HIV-1 cell free infection at a dose response manner. They were however largely ineffective against the cell-associated virus. AgNPs alone however were able to inhibit both cell free and cell associated virus infection at a dose dependent manner. AgNPs when mixed together with NABs significantly increased inhibition of Cell associated HIV-1.


The addition of AgNPs to NABs has significantly increased the neutralizing potency of NABs in prevention of cell-associated HIV-1 transmission/infection.

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Correspondence to Dinesh K Singh.

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This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Singh, D.K., Lara, H.H. Inhibition of cell-associated HIV-1 by silver nanoparticles. Retrovirology 9 (Suppl 1), O1 (2012).

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