A bifunctional aptamer-siRNA chimera targeting ACE2 for the inhibition of SARS-CoV-2 S pseudovirus entry and replication

d) of 5.41 ± 1.23 nM. Molecular docking and competitive binding assays confirm that AA2 sterically hinders the interaction between the viral spike receptor-binding domain (RBD) and ACE2. Consequently, AA2 demonstrates potent neutralization of SARS-CoV-2 S pseudovirus entry into host cells. To achieve a synergistic antiviral effect, we engineer an aptamer-siRNA chimera (AsiC) by conjugating AA2 to a short interfering RNA (siRNA) targeting the GFP coding region of the pseudovirus genome. This AsiC construct significantly represses viral replication compared to aptamer or siRNA treatment alone, validating a dual mechanism of action that combines receptor blockade with targeted gene silencing. This study establishes a robust proof-of-concept for an ACE2-targeted AsiC, representing a new class of dual-function antiviral therapeutics with the potential to effectively combat current and future ACE2-dependent coronaviruses.