NANOPARTICLES carrying a toxin found in bee venom can destroy the human immunodeficiency virus (HIV) while leaving surrounding cells unharmed, scientists at the Washington University School of Medicine in St. Louis have found. The finding is an important step towards developing a vaginal gel that may prevent the spread of HIV. The study appears in the current issue of Antiviral Therapy.
Bee venom contains a potent toxin called melittin that can poke holes in the protective envelope that surrounds HIV and other viruses. Significantly, by adding certain protective bumpers to the nanoparticle surface, the study has shown that melittin loaded onto these nanoparticles does not harm normal cells.
When the nanoparticles come into contact with normal cells, which are much larger in size, the particles simply bounce off. But HIV is smaller than the nanoparticle, so it fits between the bumpers and makes contact with the surface of the nanoparticle that harbours the bee toxin. Joshua Hood, one of the authors of the paper, says: “The melittin forms little pore-like attack complexes and ruptures the envelope, stripping it off the virus.” An advantage of this approach is that the nanoparticle attacks an essential part of the virus’ structure. In contrast, most anti-HIV drugs inhibit the virus’ ability to replicate, which does nothing to stop initial infection, and some strains of the virus have found ways to reproduce anyway. Hood also sees potential for using nanoparticles with melittin as therapy for existing HIV infections, especially those that are drug-resistant. Many viruses, including hepatitis B and C, rely on the same kind of protective envelope and would be vulnerable to melittinas well, according to the researchers. The paper’s lead author, Samuel A. Wickline, has shown that melittin-loaded nanoparticles are effective in killing tumour cells too.