Efficient Targeted Delivery of Bifunctional Circular Aptamer‐ASO Chimera to Suppress the SARS‐CoV‐2 Proliferation and Inflammation

Abstract

Inhibition of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and excessive in ammation is the current task in the prevention and treatment of COVID-19. Here, we designed a dualfunction circular aptamerASO chimera (circSApt-NASO) to suppress SARS-CoV-2 replication and in ammation. The chemically unmodi ed circSApt-NASO exhibited high serum stability by arti cial cyclization, signi cantly enhancing the utility of oligonucleotides. It presents great e ciency in knocking down, demonstrating the superiority of the circular ASO as a novel tool for sequence-speci c silencing of gene expression. Furthermore, we propose and demonstrate that the SApt binding to spike protein enables the chimera to be e ciently delivered into the susceptible host cells expressing ACE2 along with the infection of SARS-CoV-2. At high concentrations of SARS-CoV-2, the e ciency of targeted delivery of circSApt-NASO can even be compared to transfection. Among them, the anti-spike aptamer (SApt) that blocks the Spike-TLR4 interaction potently inhibits spike-induced in ammation. The NASO targeting to silence N genes not only display robust anti-N-induced in ammatory activity, but also achieve e cient inhibition of SARS-CoV-2 replication. Therefore, bene ting from the high stability of the cyclization, antispike aptamer-dependent and viral infection-mediate targeted delivery, the circSApt-NASO displays robust potential against authentic SARS-CoV-2 and Omicron (B.1.1.529), providing a promising speci c antiin ammatory and anti-proliferative reagent for therapeutic COVID-19 based on the oligonucleotide therapeutics strategy.

Aptamer-based assembly systems for SARS-CoV-2 detection and therapeutics

“…275 Yang et al designed a circular aptamer-ASO chimera for the simultaneous suppression of SARS-CoV-2 replication and inflammation. 276 On the one hand, the aptamers bound to the S protein contributed to driving the aptamer-ASO chimera to be efficiently internalized by ACE-overexpressing host cells. On the other hand, the ASO targeting N genes potently expressed anti-N-induced inflammatory activity after entering cells and achieved the inhibition of SARS-CoV-2 proliferation.…”

Aptamer‐based strategies against SARS‐CoV‐2 viruses

“…(d) Design of dual‐function circSApt1‐NASO2 and mechanism of inhibiting inflammatory and replication of SARS‐CoV‐2. Reproduced with permission [77] . Copyright 2023, Wiley.…”

“…Thus, targeting the N gene and inhibiting its expression is another effective therapeutic strategy. Based on this, the Zhao group constructed a dual‐function circular SApt1‐NASO2 chimera (circSApt1‐NASO2) using ST‐6‐1 (SApt1) and antisense oligonucleotides (NASO2) to silence N genes [77] (Figure 8d). CircSApt1‐NASO2 showed high serum stability, and not only blocks the S‐TLR4 interaction by SApt1 component to inhibit S protein‐introduced inflammation, but also specifically silences the N gene and blocks the replication of the virus by the NASO2 component to inhibit N protein‐induced inflammation even if SARS‐CoV‐2 has entered the host cells.…”

Harnessing aptamers against COVID-19: A therapeutic strategy

“…The chimera inhibited both S-induced inflammation and viral N gene-dependent replication, displaying efficacy against the original strain and omicron variant, which highlights the potential of aptamers as synergistic treatments. 50 Further studies revealed that aptamer-functionalized lipid nanoparticles encapsulating siRNAs could target the nucleocapsid phosphoprotein. Molecular docking and antiviral tests indicated a significant inhibition of infection in human lung cells.…”