Replication Features of SARS-CoV-2 and Advantages of Targeting S Protein with Aptamers to Block Viral Entry

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a virus of the coronaviridae family. The virus enters the cell through binding to the corresponding receptor angiotensin-converting enzyme 2 (ACE2) on host cell membrane with the spike protein (S protein) on its envelope; thus, we can design inhibitors that bind the S protein to block the entry of the virus into cells. Aptamers are single stranded DNA or RNA molecules that can form specific three-dimensional structures and bind their target molecules with high affinity and specificity and thus are promising candidates for S protein inhibitors. This paper reviews the replication cycle and cell entry mechanisms of SARS-CoV-2 as well as the preparation principle and characteristics of aptamers, features a discussion of the advantages of using aptamers to target the S protein to prevent SARS-CoV-2 from infecting cells, and finally summarizes the research progress in S protein-blocking aptamers.