Abstract: A synthesis method of a targeted drug nCoVshRNA.2ACE2 of a COVID-19 virus, which includes the following steps: designing a consensus RNAi sequence siRNA of the COVID-19 virus and a variant strain thereof; synthesizing two complementary siRNAs into a small hairpin-shaped shRNA with a loop, and synthesizing ACE2 or a cell penetrating peptide ACE2 with a receptor-binding domain (RBD) as a ligand; and ligating the ACE2 to a sense strand and an antisense strand of the shRNA separately to synthesize the nCoVshRNA.2ACE2 including a shRNA region and an ACE2 region. The bivalent ACE2 functions to neutralize the RBD and deliver the shRNA in a targeted manner; an “shRNA-ACE2-RBD-virus” complex bridged by the ACE2 allows the shRNA to enter target cells with virus infection, thereby avoiding a side effect of non-specific delivery of the shRNA to uninfected cells, as well as resisting the variant strain and neutralizing the virus with the ACE2.

Abstract: The present disclosure provides a preparation method of an artificial antibody. The preparation method includes the following steps: screening a target siRNA from a conserved gene or a microsatellite of a coronavirus, synthesizing a small hairpin RNA (shRNA) that has a loop by complementary sense and antisense strands of the siRNA, synthesizing an ACE2 capable of binding to a receptor-binding domain (RBD), and synthesizing the artificial antibody including an shRNA region and an ACE2 region by ligating the ACE2 to sense and antisense strands of the shRNA separately. The bivalent ACE2 is used for neutralization of the RBD and targeted delivery of the shRNA; the shRNA is ligated to the virus through the ACE2 and enters target cells with virus infection, thereby avoiding a side effect of non-specific delivery of the shRNA to uninfected cells, as well as resisting the variant strain and neutralizing the virus with the ACE2.