Testing the delivery system in lab dishes, the researchers from Washington University in St. Louis report that these nanoparticles improve HIV wellness by attaching to and destroying the virus without damaging cells. This has offered an early glimpse of a technology that might one day prevent HIV infection in some people, albeit with a lot more testing. Antony Gomes, a physiologist at the University of Calcutta in India, who studies the medical use of venoms, commented, ‘This is definitely a novel approach. There are very few reports available on venom-based treatment against viruses. This type of research has the potential to proceed further for product development.’
Lead by physician-researcher Joshua Hood, the researchers found that the toxin-carrying nanoparticles preferentially locked onto HIV and delivered their venom component; a toxin called melittin. This poked holes in HIV’s protective protein coat, which meant that the amounts of the virus were sharply reduced. The researchers then went on to test the venom on healthy human cells obtained from vaginal walls, because this is often where HIV enters the body in women.
Because the nanoparticles holding the melittin come equipped with protective structures attached on their outsides, the researchers discovered that the vaginal cells were largely unaffected by the treatment, in spite of the fact that melittin is known to degrade cell membranes. The protective structures act as bumpers to prevent the nanoparticles — and, more importantly, the toxin they carry — from contacting the cell membrane. This, along with a specific lock-and-key structure that fits onto the virus’s protein shell, allows the nanoparticle to bind to the much smaller virus.
However, Bruno Sarmento, a biotechnology researcher at the University of Porto, in Portugal, noted much still needs to be mastered if this is to become a working drug. ‘Particular attention and care must be taken in order to reproduce nanoparticles in a robust and homogeneous way to guarantee uniformity of the drug,’ he said, adding that a vaginal gel using this technology would need adhesive properties to guarantee that the nanoparticles remain in the right place, and that the virus is prevented from entering the bloodstream.