angstrom ngstrom-scale silver particles potently combat SARS-CoV-2 infection by suppressing the ACE2 expression and inflammatory responses

The SARS-CoV-2 pandemic has become a severe global public health event, and the development of protective and therapeutic strategies is urgently needed. Downregulation of angiotensin converting enzyme 2 (ACE2; one of the important SARS-CoV-2 entry receptors) and aberrant inflammatory responses (cytokine storm) are the main targets to inhibit and control COVID-19 invasion. Silver nanomaterials have well-known pharmaceutical properties, including antiviral, antibacterial, and anticancer properties. Here, based on a self-established metal evaporation-condensation-size graded collection system, smaller silver particles reaching the angstrom ngstrom scale (Ag angstrom Ps) were fabricated and coated with fructose to obtain a stabilized Ag angstrom P solution (F-Ag angstrom Ps). F-Ag angstrom Ps potently inactivated SARS-CoV-2 and prevented viral infection. Considering the application of anti-SARS-CoV-2, a sterilized F-Ag angstrom P solution was produced via spray formulation. In our model, the F-Ag angstrom P spray downregulated ACE2 expression and attenuated proinflammatory factors. Moreover, F-Ag angstrom Ps were found to be rapidly eliminated to avoid respiratory and systemic toxicity in this study as well as our previous studies. This work presents a safe and potent anti-SARS-CoV-2 agent using an F-Ag angstrom P spray.