Gold nanorods may thwart pandemics

Gold nanorods that deliver an innate immune activator to treat influenza infection may prove instrumental in thwarting pandemics of seasonal flu, H1N1 and other drug-resistant viruses, according to scientists at the University at Buffalo and the Centers for Disease Control and Prevention.

"The novelty of this approach is that most of these kinds of RNA viruses share a common host-response immune pathway; that is what we have targeted with our nanoparticle therapy. By enhancing the host immune response, we avoid the difficulty of ongoing viral resistance generated through mutations," explains lead author Krishnan Chakravarthy.

When a person has the flu, a certain RNA sensor activates a person's innate immune system and a ligand that senses the impending infection. However, it has proven difficult for scientists to get the ligand into cells. The UB and CDC researchers sought to combat this difficulty by showing how to attach the RNA-sensing ligand, 5'PPP-ssRNA, to biocompatible gold nanorods and deliver the molecule to cultured human epithelial cells infected either with a seasonal influenza or the pandemic 2009 H1N1.

The cells successfully internalized the virus, and the nanocomplex activated an antiviral response, helping to reduce replication of both seasonal and 2009 H1N1 influenza viruses. "The gold nanorods protect the RNA from degrading once inside cells, while allowing for more selected targeting of cells," says co-author Paul R. Knight III, professor of anesthesiology, microbiology and infectious diseases in the UB School of Medicine and Biomedical Sciences; and director of its MD/PhD program.

These findings suggest that biocompatible nanocomplexes may hold potential for treating seasonal and pandemic influenza outbreaks, the authors explain in their paper published in the Proceedings of the National Academy of Sciences. Based on these in vitro results, the researchers are beginning animal studies, according to a UB statement.

"This joint research by UB and the CDC has the potential to usher in a new generation of antiviral medicines to aggressively treat a broad range of infectious diseases, from H1N1 to avian flu and perhaps Ebola, that are becoming increasingly resistant to the medicines used against them," says UB team leader Paras Prasad, executive director of the UB Institute for Lasers, Photonics and Biophotonics (ILPB) and SUNY Distinguished Professor in the departments of Chemistry, Physics, Electrical Engineering and Medicine.

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