Silicon nitride: a potent solid-state bioceramic inactivator of ssRNA viruses
Giuseppe Pezzotti, Francesco Boschetto, Eriko Ohgitani, Yuki Fujita, Wenliang Zhu, Elia Marin, Bryan J. McEntire, B. Sonny Bal, Osam Mazda
Abstract
Abstract Surface inactivation of human microbial pathogens has a long history. The Smith Papyrus (2600 ~ 2200 B.C.) described the use of copper surfaces to sterilize chest wounds and drinking water. Brass and bronze on doorknobs can discourage microbial spread in hospitals, and metal-base surface coatings are used in hygiene-sensitive environments, both as inactivators and modulators of cellular immunity. A limitation of these approaches is that the reactive oxygen radicals (ROS) generated at metal surfaces also damage human cells by oxidizing their proteins and lipids. Silicon nitride (Si 3 N 4 ) is a non-oxide ceramic compound with known surface bacterial resistance. We show here that off-stoichiometric reactions at Si 3 N 4 surfaces are also capable of inactivating different types of single-stranded RNA (ssRNA) viruses independent of whether their structure presents an envelop or not. The antiviral property of Si 3 N 4 derives from a hydrolysis reaction at its surface and the subsequent formation of reactive nitrogen species (RNS) in doses that could be metabolized by mammalian cells but are lethal to pathogens. Real-time reverse transcription (RT)-polymerase chain reaction (PCR) tests of viral RNA and in situ Raman spectroscopy suggested that the products of Si 3 N 4 hydrolysis directly react with viral proteins and RNA. Si 3 N 4 may have a role in controlling human epidemics related to ssRNA mutant viruses.