Novel mechanisms of alkyldimethylbenzalkonium chloride in virucidal activity

The cationic surfactant, alkyldimethylbenzalkonium chloride (BAC), effectively inactivates enveloped viruses, but the underlying mechanism of action is poorly understood. Therefore, this study attempted to elucidate the inactivation mechanism of BAC using actual viruses and characterize the state of BAC in water under the same conditions. Here, we show that at concentrations below the critical micelle concentration (CMC), partial membrane disruption by BAC monomers contributes to the inactivation mechanism. At concentrations above the CMC, solubilization of the envelope component also contributes to virucidal activity. Concentration-related differences in the inactivation mechanism were further evaluated based on the kinetic equation of the reaction, which showed that physicochemical studies are directly related to biochemistry. As enveloped viruses can be viewed as vesicles based on their structure, the results of this study should enhance investigations of non-virus biological vesicles, such as exosomes and drug delivery systems.