• A novel DNA aptamer (AA2) targeting human ACE2 was identified via SELEX, with high affinity (Kd = 5.41 nM) and ability to block SARS-CoV-2 S protein RBD binding.
• The aptamer-siRNA chimera (AsiC) combining AA2 with a siRNA targeting the pseudovirus genome achieves synergistic inhibition of viral entry and replication.
• This dual-function approach offers a promising strategy against emerging SARS-CoV-2 variants by targeting a conserved host receptor.
• The study provides proof-of-concept for ACE2-targeted AsiCs as a new class of broad-spectrum antiviral therapeutics.