Objective:To assess aptamer-based assays for diagnosing latent tuberculosis infection(LTBI).Methods:Literature from Medline,ScienceDirect,and Scopus,covering publications from January 1,2012,to December 31,2023,was ex...Objective:To assess aptamer-based assays for diagnosing latent tuberculosis infection(LTBI).Methods:Literature from Medline,ScienceDirect,and Scopus,covering publications from January 1,2012,to December 31,2023,was examined.This review evaluates different aptamers,biomarkers,sample types,sample sizes,reference assays,and the assays'sensitivity and specificity.By using the Quality Assessment of Diagnostic Accuracy Studies 2,the risk of bias in each study was evaluated.Results:Aptamer-based assays generally showed a sensitivity of 90%(95%CI:75%-100%)and specificity of 90%(95%CI:50%-100%),where optical aptasensor showed the highest sensitivity and specificity at 100%.Serum samples were frequently used to enhance antigen detectability,improving the assay’s performance.Meanwhile,HspX was the most studied biomarker,followed by MPT64,and IFN-γ.Conclusions:Aptamer-based assays could be reliable alternatives to current LTBI detection methods,but further research is needed to validate their clinical efficacy.展开更多
Pseudorabies virus(PRV,SuidAlphaherpesvirus 1)causes substantial economic losses in swine production.Here,we report the development of DNA aptamers targeting the PRV glycoprotein D(gD)through an optimized SELEX protoc...Pseudorabies virus(PRV,SuidAlphaherpesvirus 1)causes substantial economic losses in swine production.Here,we report the development of DNA aptamers targeting the PRV glycoprotein D(gD)through an optimized SELEX protocol.After 15 selection cycles,Apt-gD-2 demonstrated nanomolar affinity(Kd=6.107±0.476 nM)and high specificity for gD,as validated by an enzyme-linked aptamer-sorbent assay(ELASA)and fluorescence microscopy.Molecular docking revealed hydrogen bonding as the key interaction mechanism.The developed ic-ELASA achieved 83.3%concordance with qPCR in clinical samples,supporting its utility for on-farm PRV surveillance.These findings highlight the potential of aptamer-based diagnostic methods for rapid,sensitive,and onsite detection of PRV,offering a promising tool for disease control in the swine industry.展开更多
Diabetes and insulinoma represent opposing alterations in pancreatic β-cell mass,with diabetes resulting from irreversible β-cells damage and insulinoma arising from abnormal proliferation.Early diagnosis of both co...Diabetes and insulinoma represent opposing alterations in pancreatic β-cell mass,with diabetes resulting from irreversible β-cells damage and insulinoma arising from abnormal proliferation.Early diagnosis of both conditions necessitates effectiveβ-cell mass detection.Current detection methods are limited in diagnosing each condition individually or lacking timely and accurate detection.Diabetes is typically identified only after significantβ-cell loss,while insulinoma can evade conventional imaging due to their small size.Positron emission tomography/computed tomography(PET/CT)imaging,combining anatomical and functional data,enhances diagnostic accuracy but faces challenges in specificity.This study employed two RNA aptamers(m12–3773 and 1–717)modified to enhance RNase resistance and conjugated with68Ga to create ^(68)Ga-NOTA-Ap.^(68)Ga-NOTA-Ap was administered to rats with pancreaticβ-cell damage and mice with insulinoma to evaluate its ability to image islets,detect changes in pancreatic β-cell mass(BCM),and identify insulinoma.Modified with methoxy and fluoro,RNA aptamers exhibited enhanced stability and RNases resistance while retaining their dissociation constants(K_(d)).Furthermore,^(68)Ga-NOTA-Ap effectively detected changes of BCM in rats with pancreatic β-cell damage and imaged insulinoma in mice through recognition of abnormalβ-cell proliferation by recognizing clusterin and transmembrane p24 trafficking protein 6(TMED6)on pancreaticβ-cell.The developed ^(68)Ga-NOTA-Ap shows promise for early screening of diabetes and insulinoma due to its high sensitivity,specificity,and non-invasive nature.It has potential clinical applications for monitoring pancreatic β-cell function and diagnosing insulinoma.展开更多
Heterodimerization in RTKs is of vital importance in the RTK signaling and cell functions.Heterodimerization between RTKs can result in diversity of downstream signals,increasing the ability of cells to respond to ext...Heterodimerization in RTKs is of vital importance in the RTK signaling and cell functions.Heterodimerization between RTKs can result in diversity of downstream signals,increasing the ability of cells to respond to external experiments.Traditional RTKs heterodimerization always occur in the same families and is lack of agonists to activate the heterodimeric RTKs signaling pathway.Herein,we developed the DNA agonist based on bivalent aptamers for the heterodimerized RTKs of different families,AF/AM-1,which could simultaneously activate FGFR1 and c-Met signaling.It is the first agonist that realizing the heterodimerization and activation of FGFR1 and c-Met,two different RTK families.The activation of FGFR1/c-Met heterodimer result in the down-stream signals transduction,such as the phosphorylation of Akt and Erk,inducing the cell migration and proliferation.The DNA agonist for RTK heterodimer of different families would have potential applications in the fields of biomedicine.展开更多
Precision medicine has become a cornerstone in modern therapeutic strategies, with nucleic acid aptamers emerging aspivotal tools due to their unique properties. These oligonucleotide fragments, selected through the S...Precision medicine has become a cornerstone in modern therapeutic strategies, with nucleic acid aptamers emerging aspivotal tools due to their unique properties. These oligonucleotide fragments, selected through the Systematic Evolution ofLigands by Exponential Enrichment process, exhibit high affinity and specificity toward their targets, such as DNA, RNA,proteins, and other biomolecules. Nucleic acid aptamers offer significant advantages over traditional therapeutic agents,including superior biological stability, minimal immunogenicity, and the capacity for universal chemical modifications thatenhance their in vivo performance and targeting precision. In the realm of osseous tissue repair and regeneration, a complexphysiological process essential for maintaining skeletal integrity, aptamers have shown remarkable potential in influencingmolecular pathways crucial for bone regeneration, promoting osteogenic differentiation and supporting osteoblast survival. Byengineering aptamers to regulate inflammatory responses and facilitate the proliferation and differentiation of fibroblasts,these oligonucleotides can be integrated into advanced drug delivery systems, significantly improving bone repair efficacywhile minimizing adverse effects. Aptamer-mediated strategies, including the use of siRNA and miRNA mimics or inhibitors,have shown efficacy in enhancing bone mass and microstructure. These approaches hold transformative potential for treatinga range of orthopedic conditions like osteoporosis, osteosarcoma, and osteoarthritis. This review synthesizes the molecularmechanisms and biological roles of aptamers in orthopedic diseases, emphasizing their potential to drive innovative andeffective therapeutic interventions.展开更多
Ergot alkaloids are mycotoxins which can be found in food based on cereal-crops, due to a contamination of plants by fungi of the genus Claviceps. The ingestion of ergot contaminated cereal crops can lead to a severe ...Ergot alkaloids are mycotoxins which can be found in food based on cereal-crops, due to a contamination of plants by fungi of the genus Claviceps. The ingestion of ergot contaminated cereal crops can lead to a severe poisoning known as ergotism. For food and feed safety purposes, the extraction of ergot alkaloids from ergot contaminated flour was investigated. For the specific recognition of ergot alkaloids, DNA aptamer ligands specially selected for ergot alkaloids were grafted onto silica gel in order to construct a specific solid phase extraction system. The aptamer-functionalized silica gels were used to extract ergot alkaloids from a contaminated rye feed sample. The presence of ergot alkaloids eluted from the aptamer-functionalized silica gels was analyzed using LC-QTOF-MS. By using this simple system, it was possible to specifically extract ergosine, ergokryptine and ergocornine from an ergot contaminated rye feed sample. This aptamer-based extraction tool shows the applicability of aptamers for the specific extraction of toxins or natural compounds from turbid matrices in a one-step procedure.展开更多
An operationally simple and efficient method for the synthesis of a wide range of alkylated nucleotides under mild conditions was developed. This improved method furnishes alkylated nucleotides fi＇om both single nucl...An operationally simple and efficient method for the synthesis of a wide range of alkylated nucleotides under mild conditions was developed. This improved method furnishes alkylated nucleotides fi＇om both single nucleotides and oligonucleotides, and were prepared in high yields of 81% to 91%. Alkyl modified aptamer AS1411s were synthesized using this method and the biological activity screening results demonstrated that alkylation at the 1^st P-S site on yielded stronger target protein binding capacity, greater growth suppression effects against K562 and HL-60 cell lines, and improved serum stability, as compared with AS1411. This modified aptamer may be useful in tumor detection and treatment.展开更多
Aptamers are short,single-stranded DNA or RNA molecules that selectively bind to a target molecule.Aptamercomplement duplex(ACD)is often used to design molecular switches capable of producing a detectable signal or tr...Aptamers are short,single-stranded DNA or RNA molecules that selectively bind to a target molecule.Aptamercomplement duplex(ACD)is often used to design molecular switches capable of producing a detectable signal or triggering a structural change upon aptamer binding to a target.However,such aptamer switch generally faces an increased dissociation constant(Kd)due to the energy barrier of the complementary duplex.We reported a competitive hybridization mechanism to modulate the binding affinity of an ACD to a target adenosine.Using the computation-guided design,we calculated the aptamer folding energy for the duplex length from 11-nt to 15-nt,and experimentally measured increased apparent Kd values resulted from these extended duplexes.Using a set of strands to compete with the ACD hybridization,it reduced the aptamer folding energy to facilitate aptamer switches with decreased apparent Kd values ranging from over 400μM without a competing strand to~30μM with a competing strand.This competitive aptamer switch was also found sensitive to single-nucleotide mutations of a competing strand.Our work provides an approach to modulate the binding affinity and the sensitivity of aptamer-complement duplexes,which could be useful in the nucleic acids-based sensing and nanomedicine.展开更多
Aptamers are a class of single oligonucleotide molecules(DNA or RNA)that are screened from random DNA or RNA oligonucleotide chain libraries by the systemic evolution of ligands by exponential enrichment technology.Th...Aptamers are a class of single oligonucleotide molecules(DNA or RNA)that are screened from random DNA or RNA oligonucleotide chain libraries by the systemic evolution of ligands by exponential enrichment technology.The selected aptamers are capable of specifically binding to different targeting molecules,which is achieved by the three-dimensional structure of aptamers.Aptamers are similar in function to monoclonal antibodies,and therefore,they are also referred to as"chemical antibodies".Due to their high affinity and specificity and low immunogenicity,aptamers are topics of intense interest in today's biological targeting research especially in tumor research.They not only have high potential for clinical advances in tumor targeting detection but also are highly promising as targeted tumor drug carriers for use in tumor therapy.Various experimental studies have shown that aptamer-based diagnostic and therapeutic methods for liver cancer have great potential for application.This paper summarizes the structure,characteristics,and screening methods of aptamers and reviews the recent research progress on nucleic acid aptamers in the targeted diagnosis and treatment of liver cancer.展开更多
Aflatoxin B1(AFB1)is a highly toxic mycotoxin,and rapid and sensitive detection of AFB1 is in demand for food safety and environmental analysis.Here we described a simple aptamer molecular beacon assay for rapid detec...Aflatoxin B1(AFB1)is a highly toxic mycotoxin,and rapid and sensitive detection of AFB1 is in demand for food safety and environmental analysis.Here we described a simple aptamer molecular beacon assay for rapid detection of aflatoxin B1(AFB1)by using an aptamer with a fluorescein(FAM)label at the 50 end and a fluorescence quencher(black hole quencher 1,BHQ1)at the 30 end.In the presence of AFB1,the aptamer probe bound with AFB1 and induced a hairpin structure,drawing FAM and BHQ1 into close proximity and leading to fluorescence quenching.This assay allowed for a detection limit of 3.9 nmol/L and a dynamic range from 3.9 nmol/L to 4 mmol/L.Specificity test showed other mycotoxins including ochratoxin A,ochratoxin B,fumonisin B1,fumonisin B2,and zearalenone had negligible influence on detection of AFB1.AFB1 spiked in diluted liquor wine,methanol,or corn flour samples was successfully detected by using this aptamer probe,and the assay showed potential for real sample analysis.展开更多
Bisphenol A(BPA)is one of the environmental endocrine disruptors(EDCs),and BPA contamination in environment can cause high risks to human health.Rapid determination of BPA on sites is in high demand in environmental a...Bisphenol A(BPA)is one of the environmental endocrine disruptors(EDCs),and BPA contamination in environment can cause high risks to human health.Rapid determination of BPA on sites is in high demand in environmental analysis.Taking advantage of aptamers as affinity ligands and fluorescence anisotropy(FA)analysis,we developed a simple and rapid FA assay for BPA by employing a single tetramethylrhodamine(TMR)labeled short 35-mer DNA aptamer against BPA.The assay is based on the BPA-binding induced conformation change of TMR-labeled aptamer and alteration of interaction between TMR and guanine bases,resulting in change of FA signals.We screened the FA change of aptamer probes having TMR label on a specific site of the aptamer upon BPA addition.The aptamer with a TMR label on the 22nd T base showed large FA-decreasing response to BPA and maintained good binding affinity to BPA.By using this TMR-labeled aptamer,we achieved FA detection of BPA with a detection limit of 0.5μmol/L under the optimized conditions.This assay was selective towards BPA and enabled the detection of BPA spiked in tap water sample,showing the potential applications on water samples.展开更多
The detection of bacterial pathogen such as Staphylococcus aureus(S.aureus) is essential for the regulation of food hygiene and disease diagnosis.Herein,we developed a simple one-step fluorescence resonance energy tra...The detection of bacterial pathogen such as Staphylococcus aureus(S.aureus) is essential for the regulation of food hygiene and disease diagnosis.Herein,we developed a simple one-step fluorescence resonance energy transfer(FRET)-based sensor for specific and sensitive detection of S.aureus in food and serum samples,in which aptamer-modified quantum dots(aptamer-QDs) was employed as the energy donor and antibiotic of teicoplanin functionalized-gold nanoparticles(Teico-AuNPs) was chosen as the energy acceptor.Within 1 h,the FRET-based sensor showed a linear range of from 10 cfu/mL to 5 × 10^(8) cfu/mL,with the low limit of detection(LOD,2 cfu/mL) for S.aureus in buffer.When further applied to assay S.aureus in real samples,the FRET-based sensor showed good recoveries ranging from 84.5% to 110.0%,with relative standard derivations(RSDs) of 0.01%-0.44% and a LOD of 100 cfu/mL in milk,orange juice and human serum.展开更多
Hepatitis B virus surface antigen （HBsAg）, a specific antigen on the membrane of Hepatitis B virus （HBV）-infected cells, provides a perfect target for therapeutic drugs. The development of reagents with high affin...Hepatitis B virus surface antigen （HBsAg）, a specific antigen on the membrane of Hepatitis B virus （HBV）-infected cells, provides a perfect target for therapeutic drugs. The development of reagents with high affinity and specificity to the HBsAg is of great significance to the early-stage diagnosis and treatment of HBV infection. Herein, we report the selection of RNA aptamers that can specifically bind to HBsAg protein and HBsAg-positive hepatocytes. One high affinity aptamer, HBs-A22, was isolated from an initial 115 met library of -1.1 ×10^15 random-sequence RNA molecules using the SELEX procedure. The selected aptamer HBs-A22 bound specifically to hepatoma cell line HepG2.2.15 that expresses HBsAg but did not bind to HBsAg-devoid HepG2 cells. This is the first reported RNA aptamer which could bind to a HBV specific antigen. This newly isolated aptamer could be modified to deliver imaging, diagnostic, and therapeutic agents targeted at HBV-infected cells.展开更多
Liquid biopsy is a technology that exhibits potential to detect cancer early,monitor therapies,and predict cancer prognosis due to its unique characteristics,including noninvasive sampling and real-time analysis.Circu...Liquid biopsy is a technology that exhibits potential to detect cancer early,monitor therapies,and predict cancer prognosis due to its unique characteristics,including noninvasive sampling and real-time analysis.Circulating tumor cells(CTCs)and extracellular vesicles(EVs)are two important components of circulating targets,carrying substantial disease-related molecular information and playing a key role in liquid biopsy.Aptamers are single-stranded oligonucleotides with superior affinity and specificity,and they can bind to targets by folding into unique tertiary structures.Aptamer-based microfluidic platforms offer new ways to enhance the purity and capture efficiency of CTCs and EVs by combining the advantages of microfluidic chips as isolation platforms and aptamers as recognition tools.In this review,we first briefly introduce some new strategies for aptamer discovery based on traditional and aptamer-based microfluidic approaches.Then,we subsequently summarize the progress of aptamer-based microfluidics for CTC and EV detection.Finally,we offer an outlook on the future directional challenges of aptamer-based microfluidics for circulating targets in clinical applications.展开更多
Okadaic acid(OA)is a typical marine toxin with strong toxicity causing diarrheic shellfish poisoning(DSP).Aptamers show great advantages in toxin detection and attract increasing attentions in the field of food analys...Okadaic acid(OA)is a typical marine toxin with strong toxicity causing diarrheic shellfish poisoning(DSP).Aptamers show great advantages in toxin detection and attract increasing attentions in the field of food analysis.In this study,a label-free col-orimetric aptasensor was constructed for visual and rapid detection of OA in shellfish.To exploit the binding capability of the anti-OA aptamer,the inherent molecular recognition mechanism of aptamer and OA was studied,based on molecular docking,fluorescent assay,and biolayer interferometry.Consistent results showed that the stem-loop near the 3’terminal of the aptamer exhibit dominate binding capacity.Based on the revealed recognition information,the aptamer was thus rationally utilized and combined with AuNPs and cationic polymer polydiallyl dimethyl ammonium chloride(PDDA)for the development of the label-free colorimetric aptasensor,in which the 3’terminal was thoroughly exposed to OA.The aptasensor provided robust performance with a linear detection range of 100-1200 nmol L-1,a limit of detection of 41.30 nmol L-1,recovery rates of 91.6%-106.2%,as well as a high selectivity towards OA in shellfish samples.The whole detection process can be completed within 1 h.To our best knowledge,this is the first time that the anti-OA aptamer was thoroughly studied,and a label-free colorimetric aptasensor was rationally designed in this way.This study not only provides a rapid detection method for highly sensitive and specific detection of OA,but also serves as a reference for the design of efficient aptasensors in the future.展开更多
基金supported by Higher Institution Centre of Excellence(HICoE)Grant(A305-KR-AKH002-0000000278-K134)from the Ministry of Higher Education,Malaysia.
文摘Objective:To assess aptamer-based assays for diagnosing latent tuberculosis infection(LTBI).Methods:Literature from Medline,ScienceDirect,and Scopus,covering publications from January 1,2012,to December 31,2023,was examined.This review evaluates different aptamers,biomarkers,sample types,sample sizes,reference assays,and the assays'sensitivity and specificity.By using the Quality Assessment of Diagnostic Accuracy Studies 2,the risk of bias in each study was evaluated.Results:Aptamer-based assays generally showed a sensitivity of 90%(95%CI:75%-100%)and specificity of 90%(95%CI:50%-100%),where optical aptasensor showed the highest sensitivity and specificity at 100%.Serum samples were frequently used to enhance antigen detectability,improving the assay’s performance.Meanwhile,HspX was the most studied biomarker,followed by MPT64,and IFN-γ.Conclusions:Aptamer-based assays could be reliable alternatives to current LTBI detection methods,but further research is needed to validate their clinical efficacy.
基金supported by the Henan Provincial Science and Technology Research Project(Grant No.242102110019)the National Natural Science Foundation of China(Grant No.31972672).
文摘Pseudorabies virus(PRV,SuidAlphaherpesvirus 1)causes substantial economic losses in swine production.Here,we report the development of DNA aptamers targeting the PRV glycoprotein D(gD)through an optimized SELEX protocol.After 15 selection cycles,Apt-gD-2 demonstrated nanomolar affinity(Kd=6.107±0.476 nM)and high specificity for gD,as validated by an enzyme-linked aptamer-sorbent assay(ELASA)and fluorescence microscopy.Molecular docking revealed hydrogen bonding as the key interaction mechanism.The developed ic-ELASA achieved 83.3%concordance with qPCR in clinical samples,supporting its utility for on-farm PRV surveillance.These findings highlight the potential of aptamer-based diagnostic methods for rapid,sensitive,and onsite detection of PRV,offering a promising tool for disease control in the swine industry.
基金supported by National Natural Science Foundation of China(No.82002241)National Key Research and Development Program of China(No.2020YFA0909000)“Clinic Plus”Outstanding Project(No.2024ZY012)from Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine。
文摘Diabetes and insulinoma represent opposing alterations in pancreatic β-cell mass,with diabetes resulting from irreversible β-cells damage and insulinoma arising from abnormal proliferation.Early diagnosis of both conditions necessitates effectiveβ-cell mass detection.Current detection methods are limited in diagnosing each condition individually or lacking timely and accurate detection.Diabetes is typically identified only after significantβ-cell loss,while insulinoma can evade conventional imaging due to their small size.Positron emission tomography/computed tomography(PET/CT)imaging,combining anatomical and functional data,enhances diagnostic accuracy but faces challenges in specificity.This study employed two RNA aptamers(m12–3773 and 1–717)modified to enhance RNase resistance and conjugated with68Ga to create ^(68)Ga-NOTA-Ap.^(68)Ga-NOTA-Ap was administered to rats with pancreaticβ-cell damage and mice with insulinoma to evaluate its ability to image islets,detect changes in pancreatic β-cell mass(BCM),and identify insulinoma.Modified with methoxy and fluoro,RNA aptamers exhibited enhanced stability and RNases resistance while retaining their dissociation constants(K_(d)).Furthermore,^(68)Ga-NOTA-Ap effectively detected changes of BCM in rats with pancreatic β-cell damage and imaged insulinoma in mice through recognition of abnormalβ-cell proliferation by recognizing clusterin and transmembrane p24 trafficking protein 6(TMED6)on pancreaticβ-cell.The developed ^(68)Ga-NOTA-Ap shows promise for early screening of diabetes and insulinoma due to its high sensitivity,specificity,and non-invasive nature.It has potential clinical applications for monitoring pancreatic β-cell function and diagnosing insulinoma.
基金the National Natural Science Foundation of China(Nos.22104158,82174104,U1903211)the Natural Science Foundation of Hunan Province(No.2021JJ40041)+1 种基金Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011346)Shenzhen Science and Technology Program(No.SZBH202130)。
文摘Heterodimerization in RTKs is of vital importance in the RTK signaling and cell functions.Heterodimerization between RTKs can result in diversity of downstream signals,increasing the ability of cells to respond to external experiments.Traditional RTKs heterodimerization always occur in the same families and is lack of agonists to activate the heterodimeric RTKs signaling pathway.Herein,we developed the DNA agonist based on bivalent aptamers for the heterodimerized RTKs of different families,AF/AM-1,which could simultaneously activate FGFR1 and c-Met signaling.It is the first agonist that realizing the heterodimerization and activation of FGFR1 and c-Met,two different RTK families.The activation of FGFR1/c-Met heterodimer result in the down-stream signals transduction,such as the phosphorylation of Akt and Erk,inducing the cell migration and proliferation.The DNA agonist for RTK heterodimer of different families would have potential applications in the fields of biomedicine.
基金Key research and development projects of Sichuan Science and Technology Plan Project(2024YFFK0135)Fujian Provincial Natural Science Foundation of China(2024J011450).
文摘Precision medicine has become a cornerstone in modern therapeutic strategies, with nucleic acid aptamers emerging aspivotal tools due to their unique properties. These oligonucleotide fragments, selected through the Systematic Evolution ofLigands by Exponential Enrichment process, exhibit high affinity and specificity toward their targets, such as DNA, RNA,proteins, and other biomolecules. Nucleic acid aptamers offer significant advantages over traditional therapeutic agents,including superior biological stability, minimal immunogenicity, and the capacity for universal chemical modifications thatenhance their in vivo performance and targeting precision. In the realm of osseous tissue repair and regeneration, a complexphysiological process essential for maintaining skeletal integrity, aptamers have shown remarkable potential in influencingmolecular pathways crucial for bone regeneration, promoting osteogenic differentiation and supporting osteoblast survival. Byengineering aptamers to regulate inflammatory responses and facilitate the proliferation and differentiation of fibroblasts,these oligonucleotides can be integrated into advanced drug delivery systems, significantly improving bone repair efficacywhile minimizing adverse effects. Aptamer-mediated strategies, including the use of siRNA and miRNA mimics or inhibitors,have shown efficacy in enhancing bone mass and microstructure. These approaches hold transformative potential for treatinga range of orthopedic conditions like osteoporosis, osteosarcoma, and osteoarthritis. This review synthesizes the molecularmechanisms and biological roles of aptamers in orthopedic diseases, emphasizing their potential to drive innovative andeffective therapeutic interventions.
文摘Ergot alkaloids are mycotoxins which can be found in food based on cereal-crops, due to a contamination of plants by fungi of the genus Claviceps. The ingestion of ergot contaminated cereal crops can lead to a severe poisoning known as ergotism. For food and feed safety purposes, the extraction of ergot alkaloids from ergot contaminated flour was investigated. For the specific recognition of ergot alkaloids, DNA aptamer ligands specially selected for ergot alkaloids were grafted onto silica gel in order to construct a specific solid phase extraction system. The aptamer-functionalized silica gels were used to extract ergot alkaloids from a contaminated rye feed sample. The presence of ergot alkaloids eluted from the aptamer-functionalized silica gels was analyzed using LC-QTOF-MS. By using this simple system, it was possible to specifically extract ergosine, ergokryptine and ergocornine from an ergot contaminated rye feed sample. This aptamer-based extraction tool shows the applicability of aptamers for the specific extraction of toxins or natural compounds from turbid matrices in a one-step procedure.
基金the Ministry of Science and Technology of China(Grant No.2012CB720604)National Natural Science Foundation of China(Grant No.21332010)
文摘An operationally simple and efficient method for the synthesis of a wide range of alkylated nucleotides under mild conditions was developed. This improved method furnishes alkylated nucleotides fi＇om both single nucleotides and oligonucleotides, and were prepared in high yields of 81% to 91%. Alkyl modified aptamer AS1411s were synthesized using this method and the biological activity screening results demonstrated that alkylation at the 1^st P-S site on yielded stronger target protein binding capacity, greater growth suppression effects against K562 and HL-60 cell lines, and improved serum stability, as compared with AS1411. This modified aptamer may be useful in tumor detection and treatment.
基金supported by a PECASE award to J.F.(W911NF1910240),a DoD DURIP(W911NF2010107)and a NSF MRI(2215917)J.F.is also supported by the Rutgers TechAdvance award,NJACTS-Pilot Program and NSF PFI award(2141141)D.P.and S.L.appreciate the support of Arts and Sciences Undergraduate Research Grant from the College of Arts and Sciences at Rutgers University-Camden.The authors are grateful to the Equipment Leasing Funds from the State of New Jersey.
文摘Aptamers are short,single-stranded DNA or RNA molecules that selectively bind to a target molecule.Aptamercomplement duplex(ACD)is often used to design molecular switches capable of producing a detectable signal or triggering a structural change upon aptamer binding to a target.However,such aptamer switch generally faces an increased dissociation constant(Kd)due to the energy barrier of the complementary duplex.We reported a competitive hybridization mechanism to modulate the binding affinity of an ACD to a target adenosine.Using the computation-guided design,we calculated the aptamer folding energy for the duplex length from 11-nt to 15-nt,and experimentally measured increased apparent Kd values resulted from these extended duplexes.Using a set of strands to compete with the ACD hybridization,it reduced the aptamer folding energy to facilitate aptamer switches with decreased apparent Kd values ranging from over 400μM without a competing strand to~30μM with a competing strand.This competitive aptamer switch was also found sensitive to single-nucleotide mutations of a competing strand.Our work provides an approach to modulate the binding affinity and the sensitivity of aptamer-complement duplexes,which could be useful in the nucleic acids-based sensing and nanomedicine.
文摘Aptamers are a class of single oligonucleotide molecules(DNA or RNA)that are screened from random DNA or RNA oligonucleotide chain libraries by the systemic evolution of ligands by exponential enrichment technology.The selected aptamers are capable of specifically binding to different targeting molecules,which is achieved by the three-dimensional structure of aptamers.Aptamers are similar in function to monoclonal antibodies,and therefore,they are also referred to as"chemical antibodies".Due to their high affinity and specificity and low immunogenicity,aptamers are topics of intense interest in today's biological targeting research especially in tumor research.They not only have high potential for clinical advances in tumor targeting detection but also are highly promising as targeted tumor drug carriers for use in tumor therapy.Various experimental studies have shown that aptamer-based diagnostic and therapeutic methods for liver cancer have great potential for application.This paper summarizes the structure,characteristics,and screening methods of aptamers and reviews the recent research progress on nucleic acid aptamers in the targeted diagnosis and treatment of liver cancer.
基金financial support from the National Natural Science Foundation of China(Nos.21575153,21435008,21874146)Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB14030200)the Key Research Program of the Chinese Academy of Sciences(No.KFZD-SW-203)
文摘Aflatoxin B1(AFB1)is a highly toxic mycotoxin,and rapid and sensitive detection of AFB1 is in demand for food safety and environmental analysis.Here we described a simple aptamer molecular beacon assay for rapid detection of aflatoxin B1(AFB1)by using an aptamer with a fluorescein(FAM)label at the 50 end and a fluorescence quencher(black hole quencher 1,BHQ1)at the 30 end.In the presence of AFB1,the aptamer probe bound with AFB1 and induced a hairpin structure,drawing FAM and BHQ1 into close proximity and leading to fluorescence quenching.This assay allowed for a detection limit of 3.9 nmol/L and a dynamic range from 3.9 nmol/L to 4 mmol/L.Specificity test showed other mycotoxins including ochratoxin A,ochratoxin B,fumonisin B1,fumonisin B2,and zearalenone had negligible influence on detection of AFB1.AFB1 spiked in diluted liquor wine,methanol,or corn flour samples was successfully detected by using this aptamer probe,and the assay showed potential for real sample analysis.
基金supported by the National Natural Science Foundation of China(Nos.21874146,21575153,21435008)。
文摘Bisphenol A(BPA)is one of the environmental endocrine disruptors(EDCs),and BPA contamination in environment can cause high risks to human health.Rapid determination of BPA on sites is in high demand in environmental analysis.Taking advantage of aptamers as affinity ligands and fluorescence anisotropy(FA)analysis,we developed a simple and rapid FA assay for BPA by employing a single tetramethylrhodamine(TMR)labeled short 35-mer DNA aptamer against BPA.The assay is based on the BPA-binding induced conformation change of TMR-labeled aptamer and alteration of interaction between TMR and guanine bases,resulting in change of FA signals.We screened the FA change of aptamer probes having TMR label on a specific site of the aptamer upon BPA addition.The aptamer with a TMR label on the 22nd T base showed large FA-decreasing response to BPA and maintained good binding affinity to BPA.By using this TMR-labeled aptamer,we achieved FA detection of BPA with a detection limit of 0.5μmol/L under the optimized conditions.This assay was selective towards BPA and enabled the detection of BPA spiked in tap water sample,showing the potential applications on water samples.
基金supported by the National Natural Science Foundation of China (Nos.21974110,21575118,21976145 and 31672605)Natural Science Foundation Project of Chongqing (No.CSTC2019jcyj-msxmX0406)。
文摘The detection of bacterial pathogen such as Staphylococcus aureus(S.aureus) is essential for the regulation of food hygiene and disease diagnosis.Herein,we developed a simple one-step fluorescence resonance energy transfer(FRET)-based sensor for specific and sensitive detection of S.aureus in food and serum samples,in which aptamer-modified quantum dots(aptamer-QDs) was employed as the energy donor and antibiotic of teicoplanin functionalized-gold nanoparticles(Teico-AuNPs) was chosen as the energy acceptor.Within 1 h,the FRET-based sensor showed a linear range of from 10 cfu/mL to 5 × 10^(8) cfu/mL,with the low limit of detection(LOD,2 cfu/mL) for S.aureus in buffer.When further applied to assay S.aureus in real samples,the FRET-based sensor showed good recoveries ranging from 84.5% to 110.0%,with relative standard derivations(RSDs) of 0.01%-0.44% and a LOD of 100 cfu/mL in milk,orange juice and human serum.
基金National Mega Research Program of China(2008ZX10002-011)National Natural Science Foundation of China(30700701)National High Tech-nology Research and Development program of China(2006AA02Z128)
文摘Hepatitis B virus surface antigen （HBsAg）, a specific antigen on the membrane of Hepatitis B virus （HBV）-infected cells, provides a perfect target for therapeutic drugs. The development of reagents with high affinity and specificity to the HBsAg is of great significance to the early-stage diagnosis and treatment of HBV infection. Herein, we report the selection of RNA aptamers that can specifically bind to HBsAg protein and HBsAg-positive hepatocytes. One high affinity aptamer, HBs-A22, was isolated from an initial 115 met library of -1.1 ×10^15 random-sequence RNA molecules using the SELEX procedure. The selected aptamer HBs-A22 bound specifically to hepatoma cell line HepG2.2.15 that expresses HBsAg but did not bind to HBsAg-devoid HepG2 cells. This is the first reported RNA aptamer which could bind to a HBV specific antigen. This newly isolated aptamer could be modified to deliver imaging, diagnostic, and therapeutic agents targeted at HBV-infected cells.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.:82003710 and 82173808)the Natural Science Foundation of Guangdong Province(Grant Nos.:2020A1515010075 and 2021B1515020100)+3 种基金the Project of Educational Commission of Guangdong Province(Grant No.:2021ZDZX2012)the Guangzhou Basic and Applied Basic Research Project(Grant No.:2023A04J1163)the National Key Clinical Specialty Construction Project(Clinical Pharmacy)High-Level Clinical Key Specialty(Clinical Pharmacy)in Guangdong Province,China.
文摘Liquid biopsy is a technology that exhibits potential to detect cancer early,monitor therapies,and predict cancer prognosis due to its unique characteristics,including noninvasive sampling and real-time analysis.Circulating tumor cells(CTCs)and extracellular vesicles(EVs)are two important components of circulating targets,carrying substantial disease-related molecular information and playing a key role in liquid biopsy.Aptamers are single-stranded oligonucleotides with superior affinity and specificity,and they can bind to targets by folding into unique tertiary structures.Aptamer-based microfluidic platforms offer new ways to enhance the purity and capture efficiency of CTCs and EVs by combining the advantages of microfluidic chips as isolation platforms and aptamers as recognition tools.In this review,we first briefly introduce some new strategies for aptamer discovery based on traditional and aptamer-based microfluidic approaches.Then,we subsequently summarize the progress of aptamer-based microfluidics for CTC and EV detection.Finally,we offer an outlook on the future directional challenges of aptamer-based microfluidics for circulating targets in clinical applications.
基金funded by the National Natural Sci-ence Foundation of China(No.31801620).
文摘Okadaic acid(OA)is a typical marine toxin with strong toxicity causing diarrheic shellfish poisoning(DSP).Aptamers show great advantages in toxin detection and attract increasing attentions in the field of food analysis.In this study,a label-free col-orimetric aptasensor was constructed for visual and rapid detection of OA in shellfish.To exploit the binding capability of the anti-OA aptamer,the inherent molecular recognition mechanism of aptamer and OA was studied,based on molecular docking,fluorescent assay,and biolayer interferometry.Consistent results showed that the stem-loop near the 3’terminal of the aptamer exhibit dominate binding capacity.Based on the revealed recognition information,the aptamer was thus rationally utilized and combined with AuNPs and cationic polymer polydiallyl dimethyl ammonium chloride(PDDA)for the development of the label-free colorimetric aptasensor,in which the 3’terminal was thoroughly exposed to OA.The aptasensor provided robust performance with a linear detection range of 100-1200 nmol L-1,a limit of detection of 41.30 nmol L-1,recovery rates of 91.6%-106.2%,as well as a high selectivity towards OA in shellfish samples.The whole detection process can be completed within 1 h.To our best knowledge,this is the first time that the anti-OA aptamer was thoroughly studied,and a label-free colorimetric aptasensor was rationally designed in this way.This study not only provides a rapid detection method for highly sensitive and specific detection of OA,but also serves as a reference for the design of efficient aptasensors in the future.
