Tannic Acid Modified Silver Nanoparticles Show Antiviral Activity in Herpes Simplex Virus Type 2 Infection

The interaction between silver nanoparticles and herpesviruses is attracting great interest due to their antiviral activity and possibility to use as microbicides for oral and anogenital herpes. In this work, we demonstrate that tannic acid modified silver nanoparticles sized 13 nm, 33 nm and 46 nm are capable of reducing HSV-2 infectivity both in vitro and in vivo. The antiviral activity of tannic acid modified silver nanoparticles was size-related, required direct interaction and blocked virus attachment, penetration and further spread. All tested tannic acid modified silver nanoparticles reduced both infection and inflammatory reaction in the mouse model of HSV-2 infection when used at infection or for a post-infection treatment. Smaller-sized nanoparticles induced production of cytokines and chemokines important for anti-viral response. The corresponding control buffers with tannic acid showed inferior antiviral effects in vitro and were ineffective in blocking in vivo infection. Our results show that tannic acid modified silver nanoparticles are good candidates for microbicides used in treatment of herpesvirus infections.This work was supported by the Polish National Science Centre grant No. 2011/03/B/NZ6/04878 (for MK) and Centre for Preclinical Research and Technology (CePT) Project No. POIG.02.02.00-14-024/08-0 (for MG and MD). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscrip

Tin Oxide Nanowires Suppress Herpes Simplex Virus-1 Entry and Cell-to-Cell Membrane Fusion

The advent of nanotechnology has ushered in the use of modified nanoparticles as potential antiviral agents against diseases such as herpes simplex virus 1 and 2 (HSV-1) (HSV-2), human immunodeficiency virus (HIV), monkeypox virus, and hepatitis B virus. Here we describe the application of tin oxide (SnO(2)) nanowires as an effective treatment against HSV-1 infection. SnO(2) nanowires work as a carrier of negatively charged structures that compete with HSV-1 attachment to cell bound heparan sulfate (HS), therefore inhibiting entry and subsequent cell-to-cell spread. This promising new approach can be developed into a novel form of broad-spectrum antiviral therapy especially since HS has been shown to serve as a cellular co-receptor for a number of other viruses as well, including the respiratory syncytial virus, adeno-associated virus type 2, and human papilloma virus

Synthesis of Cellulose Nanocrystals Carrying Tyrosine Sulfate Mimetic Ligands and Inhibition of Alphavirus Infection

We present two facile approaches for introducing multivalent displays of tyrosine sulfate mimetic ligands on the surface of cellulose nanocrystals (CNCs) for application as viral inhibitors. We tested the efficacy of cellulose nanocrystals, prepared either from cotton fibers or Whatman filter paper, to inhibit alphavirus infectivity in Vero (B) cells. Cellulose nanocrystals were produced by sulfuric acid hydrolysis leading to nanocrystal surfaces decorated with anionic sulfate groups. When the fluorescent marker expressing Semliki Forest virus vector, VA7-EGFP, was incubated with CNCs, strong inhibition of virus infectivity was achieved, up to 100 and 88% for cotton and Whatman CNCs, respectively. When surface sulfate groups of CNCs were exchanged for tyrosine sulfate mimetic groups (i.e. phenyl sulfonates), improved viral inhibition was attained. Our observations suggest that the conjugation of target-specific functionalities to CNC surfaces provides a means to control their antiviral activity. Multivalent CNCs did not cause observable in vitro cytotoxicity to Vero (B) cells or human corneal epithelial (HCE-T) cells, even within the 100% virus-inhibitory concentrations. Based on the similar chemistry of known polyanionic inhibitors, our results suggest the potential application of CNCs as inhibitors of other viruses, such as human immunodeficiency virus (HIV) and herpes simplex viruses.Peer ReviewedPostprint (author's final draft