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1.
Biosens Bioelectron ; 201: 113944, 2022 Apr 01.
Article in English | MEDLINE | ID: covidwho-1588207

ABSTRACT

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.


Subject(s)
Biosensing Techniques , COVID-19 , Nucleic Acids , Humans , Nucleic Acids/genetics , Pandemics , SARS-CoV-2
2.
Nat Commun ; 12(1): 724, 2021 02 01.
Article in English | MEDLINE | ID: covidwho-1387326

ABSTRACT

Recent advances in cell-free synthetic biology have given rise to gene circuit-based sensors with the potential to provide decentralized and low-cost molecular diagnostics. However, it remains a challenge to deliver this sensing capacity into the hands of users in a practical manner. Here, we leverage the glucose meter, one of the most widely available point-of-care sensing devices, to serve as a universal reader for these decentralized diagnostics. We describe a molecular translator that can convert the activation of conventional gene circuit-based sensors into a glucose output that can be read by off-the-shelf glucose meters. We show the development of new glucogenic reporter systems, multiplexed reporter outputs and detection of nucleic acid targets down to the low attomolar range. Using this glucose-meter interface, we demonstrate the detection of a small-molecule analyte; sample-to-result diagnostics for typhoid, paratyphoid A/B; and show the potential for pandemic response with nucleic acid sensors for SARS-CoV-2.


Subject(s)
Biosensing Techniques/methods , Gene Regulatory Networks/genetics , Glucose/analysis , Nucleic Acids/analysis , Point-of-Care Systems , Point-of-Care Testing , Biosensing Techniques/instrumentation , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/virology , Glucose/metabolism , Humans , Nucleic Acids/genetics , Pandemics , SARS-CoV-2/isolation & purification , SARS-CoV-2/physiology , Typhoid Fever/blood , Typhoid Fever/diagnosis , Typhoid Fever/microbiology
4.
ACS Appl Mater Interfaces ; 12(50): 55614-55623, 2020 Dec 16.
Article in English | MEDLINE | ID: covidwho-1387129

ABSTRACT

Multiplexed detection of viral nucleic acids is important for rapid screening of viral infection. In this study, we present a molybdenum disulfide (MoS2) nanosheet-modified dendrimer droplet microarray (DMA) for rapid and sensitive detection of retroviral nucleic acids of human immunodeficiency virus-1 (HIV-1) and human immunodeficiency virus-2 (HIV-2) simultaneously. The DMA platform was fabricated by omniphobic-omniphilic patterning on a surface-grafted dendrimer substrate. Functionalized MoS2 nanosheets modified with fluorescent dye-labeled oligomer probes were prepatterned on positively charged amino-modified omniphilic spots to form a fluorescence resonance energy transfer (FRET) sensing microarray. With the formation of separated microdroplets of sample on the hydrophobic-hydrophilic micropattern, prepatterned oligomer probes specifically hybridized with the target HIV genes and detached from the MoS2 nanosheet surface due to weakening of the adsorption force, leading to fluorescence signal recovery. As a proof of concept, we used this microarray with a small sample size (<150 nL) for simultaneous detection of HIV-1 and HIV-2 nucleic acids with a limit of detection (LOD) of 50 pM. The multiplex detection capability was further demonstrated for simultaneous detection of five viral genes (HIV-1, HIV-2, ORFlab, and N genes of SARS-COV-2 and M gene of Influenza A). This work demonstrated the potential of this novel MoS2-DMA FRET sensing platform for high-throughput multiplexed viral nucleic acid screening.


Subject(s)
Biosensing Techniques , COVID-19/diagnosis , HIV Infections/diagnosis , HIV/isolation & purification , COVID-19/genetics , COVID-19/virology , Disulfides/chemistry , Fluorescence , Fluorescence Resonance Energy Transfer , HIV/pathogenicity , HIV Infections/genetics , HIV Infections/virology , Humans , Molybdenum/chemistry , Nanostructures/chemistry , Nucleic Acids/genetics , Nucleic Acids/isolation & purification , SARS-CoV-2/isolation & purification , SARS-CoV-2/pathogenicity
5.
Analyst ; 146(8): 2449-2462, 2021 Apr 21.
Article in English | MEDLINE | ID: covidwho-1201361

ABSTRACT

The COVID-19 pandemic has put the spotlight on the urgent need for integrated nucleic acid tests (NATs) for infectious diseases, especially those that can be used near patient ("point-of-care", POC), with rapid results and low cost, but without sacrificing sensitivity or specificity of gold standard PCR tests. In the US, the Clinical Laboratory Improvement Amendments Certificate of Waiver (CLIA-waiver) is mandated by the Food and Drug Administration (FDA) and designated to any laboratory testing with high simplicity and low risk for error, suitable for application in the POC. Since the first issuance of CLIA-waiver to Abbot's ID NOW Influenza A&B in 2015, many more NAT systems have been developed, received the CLIA-waiver in the US or World Health Organization (WHO)'s pre-qualification, and deployed to the front line of infectious disease detection. This review highlights the regulatory process for FDA and WHO in evaluating these NATs and the technology innovation of existing CLIA-waived systems. Understanding the technical advancement and challenges, unmet needs, and the trends of commercialization facilitated through the regulatory processes will help pave the foundation for future development and technology transfer from research to the market place.


Subject(s)
COVID-19 , Communicable Diseases , Nucleic Acids , Communicable Diseases/diagnosis , Humans , Nucleic Acids/genetics , Pandemics , Point-of-Care Systems , Point-of-Care Testing , SARS-CoV-2
6.
J Vis Exp ; (168)2021 02 03.
Article in English | MEDLINE | ID: covidwho-1090278

ABSTRACT

Traditional methods to detect and quantify nucleic acids rely on polymerase chain reaction (PCR) and require the use of expensive thermocyclers with integrated fluorescence detection of amplicons. Isothermal nucleic acid amplification technologies eliminate the need for thermal cycling; however, fluorescence-based detection of products is still required for real-time, quantitative results. Several portable isothermal heaters with integrated fluorescence detection are now commercially available; however, the cost of these devices remains a significant barrier to widespread adoption in resource-limited settings. Described here is a protocol for the design and assembly of a modular, low-cost fluorimeter constructed from off-the-shelf components. Enclosed in a compact 3D printed housing, the fluorimeter is designed to be placed atop a commercially available heat block holding a PCR tube. The fluorimeter described here was optimized to detect fluorescein isothiocyanate (FITC) dye, but the system can be modified for use with dyes commonly used as reporters in real-time nucleic acid amplification reactions. Clinical applicability of the system is demonstrated by performing real-time nucleic acid detection with two isothermal amplification technologies: recombinase polymerase amplification (RPA) for detection of positive control DNA provided in a commercial kit and reverse transcription loop-mediated isothermal amplification (RT-LAMP) for detection of clinically meaningful levels of SARS-CoV-2 RNA.


Subject(s)
Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , Nucleic Acids/genetics , Printing, Three-Dimensional , Reverse Transcription/genetics , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , COVID-19/genetics , Health Resources , Humans , RNA, Viral/genetics , RNA, Viral/isolation & purification , Real-Time Polymerase Chain Reaction/methods
7.
Biochem Biophys Res Commun ; 591: 137-142, 2022 02 05.
Article in English | MEDLINE | ID: covidwho-1002347

ABSTRACT

The new coronavirus pneumonia (COVID-19) epidemic spread rapidly throughout the world. Considering the strong infectivity and clustering of COVID-19, early detection of infectious cases is of great significance to control the epidemic. Nucleic acid testing (NAT) plays an important role in rapid laboratory diagnosis, treatment assessment, epidemic prevention and control of COVID-19. However, since COVID-19 is caused by a new emerging virus and NAT for COVID-19 has not been clinically applied before, false negative results inconsistent with clinical diagnosis have appeared in clinical practice. Therefore, it is urgent to improve the sensitivity of NAT for COVID-19. This study aimed to summarize the current situation and prospect of NAT based on the latest findings on COVID-19 infection. Also, the quality control of sample collection was discussed. Hopefully, this study could help to improve the effectiveness of NAT for COVID-19.


Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , Genome, Viral/genetics , Nucleic Acids/genetics , SARS-CoV-2/genetics , COVID-19/epidemiology , COVID-19/virology , Clinical Laboratory Techniques/methods , Humans , Pandemics/prevention & control , Quality Control , SARS-CoV-2/pathogenicity , Sensitivity and Specificity , Specimen Handling/methods , Virulence/genetics
8.
Acta Ophthalmol ; 98(8): 859-863, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-260153

ABSTRACT

BACKGROUND: The current outbreak of COVID-19 has spread rapidly all over the world. Respiratory droplets and contaction with infected patients are the two major transmission routes. However, the value of tear virus nucleic acid is still not clear. We dynamic detected the SARS-CoV-2 in eye sample of one COVID-19 patient with obstruction of common lacrimal ducts. METHODS: Besides the routine examination, nasopharyngeal and eye swab were continuously measured by polymerase chain reaction assay and next-generation sequencing (NGS). Gene detection was performed for drug use guidance, and flow cytometry was performed to analyse the lymphocyte subsets. RESULTS: Nasopharyngeal swabs were positive for 22 days, but eye swabs were still continuously positive for 2 weeks after nasopharyngeal swabs turned negative. The low level of lymphocyte and the high level IL-6 lasted for almost 4 weeks, then became near normal. Next-generation sequencing (NGS) confirmed the existing of SARS-CoV-2, HSV1 and HHV6B virus nucleic acid. The gene detection for drug use guidance showed the genetic locus ABCB1 (3435T>C) rs1045642 belonged to type CC and it mean the efficiency of lopinavir-ritonavir would be significantly decreased. The flow cytometry of lymphocyte subsets showed PD-1+  CD95+ cells was accounting for 94.8% in CD3+  CD8+ T subset and for 94.8% in CD3+  TCRγδ+ T subset. CONCLUSIONS: As obstruction of common lacrimal duct, positively detection in one eye for 2 weeks more after nasopharyngeal swab became negative. More eye swabs should be collected from COVID-19 patients, especially from those immunocompromised, those with eye symptoms and those had a history of ocular diseases.


Subject(s)
COVID-19/diagnosis , Conjunctiva/virology , Eye Infections, Viral/diagnosis , Herpesvirus 1, Human/isolation & purification , Herpesvirus 6, Human/isolation & purification , Lacrimal Duct Obstruction/diagnosis , SARS-CoV-2/isolation & purification , Tears/virology , Aged , Anti-Bacterial Agents/therapeutic use , COVID-19/drug therapy , COVID-19/virology , Conjunctivitis, Viral/diagnosis , Drug Therapy, Combination , Eye Infections, Viral/drug therapy , Eye Infections, Viral/virology , Flow Cytometry , HIV Protease Inhibitors/therapeutic use , Herpes Simplex/diagnosis , Herpes Simplex/drug therapy , Herpes Simplex/virology , Herpesvirus 1, Human/genetics , Herpesvirus 6, Human/genetics , High-Throughput Nucleotide Sequencing , Humans , Lacrimal Duct Obstruction/drug therapy , Lacrimal Duct Obstruction/virology , Lopinavir/therapeutic use , Male , Medicine, Chinese Traditional , Moxifloxacin/therapeutic use , Nasopharynx/virology , Nucleic Acids/genetics , Polymerase Chain Reaction , RNA, Viral/genetics , Ritonavir/therapeutic use , Roseolovirus Infections/diagnosis , Roseolovirus Infections/drug therapy , Roseolovirus Infections/virology , SARS-CoV-2/genetics
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