De novo ssRNA Aptamers against the SARS-CoV-2 Main Protease: In Silico Design and Molecular Dynamics Simulation

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

Nucleic acid aptamers are oligonucleotide chains with molecular recognition properties. Compared with antibodies, aptamers show advantages given that they are readily produced via chemical synthesis and elicit minimal immunogenicity in biomedicine applications. Notably, aptamer-encoded nucleic acid assemblies further improve the binding affinity of aptamers with the targets due to their multivalent synergistic interactions. Specially, aptamers can be engineered with special topological arrangements in nucleic acid assemblies, which demonstrate spatial and valence matching towards antigens on viruses, thus showing potential in the detection and therapeutic applications of viruses. This review presents the recent progress on the aptamers explored for SARS-CoV-2 detection and infection treatment, wherein applications of aptamer-based assembly systems are introduced in detail. Screening methods and chemical modification strategies for aptamers are comprehensively summarized, and the types of aptamers employed against different target domains of SARS-CoV-2 are illustrated. The evolution of aptamer-based assembly systems for the detection and neutralization of SARS-CoV-2, as well as the construction principle and characteristics of aptamer-based DNA assemblies are demonstrated. The typically representative works are presented to demonstrate how to assemble aptamers rationally and elaborately for specific applications in SARS-CoV-2 diagnosis and neutralization. Finally, we provide deep insights into the current challenges and future perspectives towards aptamer-based nucleic acid assemblies for virus detection and neutralization in nanomedicine.

Progress of the "Molecular Informatics" Section in 2022

This is the first Editorial of the "Molecular Informatics" Section (MIS) of the International Journal of Molecular Sciences (IJMS), which was created towards the end of 2018 (the first article was submitted on 27 September 2018) and has experienced significant growth from 2018 to now [...].

Functional nucleic acids as potent therapeutics against SARS-CoV-2 infection

The COVID-19 pandemic has posed a severe threat to human life and the global economy. Although conventional treatments, including vaccines, antibodies, and small-molecule inhibitors, have been broadly developed, they usually fall behind the constant mutation of SARS-CoV-2, due to the long screening process and high production cost. Functional nucleic acid (FNA)-based therapeutics are a newly emerging promising means against COVID-19, considering their timely adaption to different mutants and easy design for broad-spectrum virus inhibition. In this review, we survey typical FNA-related therapeutics against SARS-CoV-2 infection, including aptamers, aptamer-integrated DNA frameworks, functional RNA, and CRISPR-Cas technology. We first introduce the pathogenesis, transmission, and evolution of SARS-CoV-2, then analyze the existing therapeutic and prophylactic strategies, including their pros and cons. Subsequently, the FNAs are recommended as potent alternative therapeutics from their screening process and controllable engineering to effective neutralization. Finally, we put forward the remaining challenges of the existing field and sketch out the future development directions.

Inspirations of Biomimetic Affinity Ligands: A Review

Affinity chromatography is a well-known method dependent on molecular recognition and is used to purify biomolecules by mimicking the specific interactions between the biomolecules and their substrates. Enzyme substrates, cofactors, antigens, and inhibitors are generally utilized as bioligands in affinity chromatography. However, their cost, instability, and leakage problems are the main drawbacks of these bioligands. Biomimetic affinity ligands can recognize their target molecules with high selectivity. Their cost-effectiveness and chemical and biological stabilities make these antibody analogs favorable candidates for affinity chromatography applications. Biomimetics applies to nature and aims to develop nanodevices, processes, and nanomaterials. Today, biomimetics provides a design approach to the biomimetic affinity ligands with the aid of computational methods, rational design, and other approaches to meet the requirements of the bioligands and improve the downstream process. This review highlighted the recent trends in designing biomimetic affinity ligands and summarized their binding interactions with the target molecules with computational approaches.

Functional nucleic acids as modular components against SARS-CoV-2: From diagnosis to therapeutics

Coronavirus Disease 2019 (COVID-19), which poses an extremely serious global impact on human public healthcare, represents a high transmission and disease-causing viral infection caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that is expanding at a rapid pace. Therefore, it is urgent for researchers to establish effective platforms for the assay and treatment of SARS-CoV-2. Functional nucleic acids (FNAs), comprising aptamers and nucleases, are of primary concern within the biological and medical communities owing of the distinctive properties of their target recognition and catalysis. This review will concentrate on the essential aspects of insights regarding FNAs and their technological expertise for the diagnostic and therapeutic utilization against COVID-19. We first offer a historical perspective of the COVID-19 pandemics, its clinical characteristics and potential biomarkers. Then, we briefly discuss the current diagnostic and therapeutic methodology towards COVID-19, highlighting the superiorities and existing shortcomings. After that, we introduce the key features of FNAs, and summarize recent progress of in vitro selection of FNAs for SARS-CoV-2 specific proteins and RNAs, followed by highlighting the general concept of translating FNAs into functional probes for diagnostic and therapeutic purposes. Then, we critically review the emerging FNAs-based diagnostic and therapeutic strategies that are fast, precise, efficient, and highly specific to fight COVID-19. Finally, we identify remaining challenges and offer future outlook of this emerging field.

Recent advances of functional nucleic acid-based sensors for point-of-care detection of SARS-CoV-2

This review focuses on critical scientific barriers that the field of point-of-care (POC) testing of SARS-CoV-2 is facing and possible solutions to overcome these barriers using functional nucleic acid (FNA)-based technology. Beyond the summary of recent advances in FNA-based sensors for COVID-19 diagnostics, our goal is to outline how FNA might serve to overcome the scientific barriers that currently available diagnostic approaches are suffering. The first introductory section on the operationalization of the COVID-19 pandemic in historical view and its clinical features contextualizes essential SARS-CoV-2-specific biomarkers. The second part highlights three major scientific barriers for POC COVID-19 diagnosis, that is, the lack of a general method for (1) designing receptors of SARS-CoV-2 variants; (2) improving sensitivity to overcome false negatives; and (3) signal readout in resource-limited settings. The subsequent part provides fundamental insights into FNA and technical tricks to successfully achieve effective COVID-19 diagnosis by using in vitro selection of FNA to overcome receptor design barriers, combining FNA with multiple DNA signal amplification strategies to improve sensitivity, and interfacing FNA with portable analyzers to overcome signal readout barriers. This review concludes with an overview of further opportunities and emerging applications for FNA-based sensors against COVID-19.