A Topology-Matching Spike Protein-Capping Tetrahedral DNA Nanocrown for SARS-CoV-2 Neutralization

The constantly mutating severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)poses great risk of efficacy loss to the present neutralizing therapeutics.Thus,it is urgently needed to develop versatile strategies that enable rapid design and engineering of potent neutralizing therapeutics for newly emerging variants.Herein,we present an unprecedented DNA nanocrown that can topologically match and multivalently bind the S-trimer of SARS-CoV-2 and thereby inhibit its infection to host cells.A neutralizing aptamer binding the N-terminal domain(NTD)supersite of the S protein was first screened and identified.It was further elaborately engineered onto the best fitting tetrahedral DNA nanostructure to form a spike protein-capping nanocrown,which can effectively block not only wild-type(WT)SARS-CoV-2 pseudovirus,but also several important mutants including D614G,N501Y,andΔ69–70.Significantly,it can evidently diminish the RNA copies of authentic WT SARS-CoV-2 in host cells by 4.6 orders of magnitude.Therefore,utilizing the aptamer selection method and the dedicated engineering route,our topology-matching DNA framework provides a versatile platform for SARS-CoV-2 inhibition and has the potential to be facilely expanded to newly emerging variants and other fatal coronaviruses.

High Mannose-Specific Aptamers for Broad-Spectrum Virus Inhibition and Cancer Targeting

High mannose oligosaccharides are characteristic and essential for immune evasion of many viruses and cancer cells.They are potential targets for viral inhibition and cancer diagnosis/therapy.Particularly,high mannose-binding reagents may be a unique asset for fighting the ongoing and mutating SARSCoV-2 virus.Lectins are prevailing reagents for saccharide binding but suffer from inadequate specificity and apparent immunogenicity.Meanwhile,other reagents for the same purpose,such as antibodies and aptamers,have rarely been reported.Herein,using molecularly imprinted magnetic nanoparticles as a potent platform,we report a smart selection method for fine screening of high mannose-specific aptamers.Monovalent aptamers were first effectively screened within eight rounds of selection.Multivalent aptamers,in the forms of dendritic polymer or tetrahedral DNA nanostructure(TDN),were further engineered.The aptamers exhibited high affinity toward the spike protein of SARS-CoV-2 and the envelope protein GP120 of HIV.Both the monovalent aptamer and its TDN form exhibited a certain inhibition effect to the SARS-CoV-2 pseudovirus.On the other hand,both the monovalent aptamer and its dendritic form permitted the recognition of cancer cells over normal cells.Therefore,as unprecedented reagents for broad-spectrum viral inhibition and cancer targeting,these aptamers hold great promise for clinical treatment and diagnosis.

New Promises of Advanced Molecular Recognition:Bioassays,Single Cell Analysis,Cancer Therapy,and Beyond

The development of biomimetic affinity materials holds great value for scientific research and practical applications.Starting from boronic acid chemistry,we developed a series of boronate affinity materials(BAMs)with desired binding properties in aspects of binding pH,affinity and selectivity.Based on BAMs,molecularly imprinted polymers(MIPs)and aptamers capable of targeting vital biomolecules were rationally designed and prepared.Using these affinity reagents as potent tools and combining with advanced analytical techniques particularly liquid chromatography,mass spectrometry and spectrometry allowed for the construction of promising analytical methods to provide new qualitative and quantitative solutions to challenging applications including targeted proteomics analysis,single cell analysis and disease diagnostics.In addition,the targeting capability of these affinity reagents particularly nanoscale MIPs opened a unique access to develop innovative nanotherapeutics for cancer treatment.