HIV, dengue, papillomavirus, herpes and Ebola - these are just some of the many viruses that kill millions of people every year, mostly children in developing countries. While drugs can be used against some viruses, there is currently no broad-spectrum treatment that is effective against several at the same time, in the same way that broad-spectrum antibiotics fight a range of bacteria.
A research team at EPFL's Supramolecular Nano-Materials and Interfaces Laboratory - Constellium Chair (SUNMIL) have created gold nanoparticles for just this purpose, and their findings could lead to a broad-spectrum treatment. Once injected in the body, these nanoparticles imitate human cells and "trick" the viruses. When the viruses bind to them - in order to infect them - the nanoparticles use pressure produced locally by this link-up to "break" the viruses, rendering them innocuous. The results of this research have been published in Nature Materials.
Pressing need for a broad-spectrum treatment
Until now, research into broad-spectrum virus treatments has only produced approaches that are toxic to humans or that work effectively in vitro - i.e., in the lab - but not in vivo. The EPFL researchers found a way around these problems by creating gold nanoparticles. They are harmless to humans, and they imitate human cell receptors - specifically the ones viruses seek for their own attachment to cells. Viruses infect human bodies by binding to replicating into cells. It is as if the nanoparticles work by tricking the viruses into thinking that they are invading a human cell. When they bind to the nanoparticles, the resulting pressure deforms the virus and opens it, rendering it harmless. Unlike other treatments, the use of pressure is non-toxic. "Viruses replicate within cells, and it is very difficult to find a chemical substance that attacks viruses without harming the host cells," says Stellacci. "But until now, that's been the only known approach attempted permanently damage viruses." The method developed at SUNMIL is unique in that it achieves permanent damage to the viral integrity without damaging living cells.
Encouraging results on several viruses
Successful in vitro experiments have been conducted on cell cultures infected by herpes simplex virus, papillomavirus (which can lead to uterine cancer), respiratory syncytial virus (RSV, which can cause pneumonia), dengue virus and HIV (lentivirus). In other tests, mice infected by RSV were cured. For this project, the SUNMIL researchers teamed up with several other universities that contributed their expertise in nanomaterials and virology.