Cell-Mimicking Nanodecoys Protect Lung Cells by Neutralization of SARS-CoV-2 Spike Proteins

Abstract Coronavirus disease of 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has grown into a global pandemic, with no specific antiviral treatments or vaccines are yet approved. The viral receptor, angiotensin-converting enzyme 2 (ACE2), has been demonstrated to play an integral role in the pathogenesis of SARS-CoV-2, necessary for host cell viral entry. Inspired by this, we synthesized ACE2 nanodecoys from human lung spheroid cells (LSCs) capable of binding the Spike protein as a potential neutralization agent for SARS-CoV-2. Our results show LSC-nanodecoys has a high affinity and neutralization efficiency to both spike protein and chemically synthesized SARS-CoV-2 mimics. In addition, non-invasive inhalation therapy in mice showed successful delivery of the nanodecoy to the lungs, as well as in-vivo retention of the nanodecoys over 72 hours after a single administration. Furthermore, inhalation of nanodecoy accelerated the clearance of SARS-CoV-2 mimics from the lung and did not cause toxicity.