Rapid,sensitive,point-of-care detection of pathogenic bacteria is important for food safety.In this study,we developed a novel quantum dot nanobeads-labelled lateral flow immunoassay strip(QBs-labelled LFIAS)combined ...Rapid,sensitive,point-of-care detection of pathogenic bacteria is important for food safety.In this study,we developed a novel quantum dot nanobeads-labelled lateral flow immunoassay strip(QBs-labelled LFIAS)combined with strand displacement loop-mediated isothermal amplification(SD-LAMP)for quantitative Salmonella Typhimurium(ST)detection.Quantum dot nanobeads(QBs)served as fluorescence reporters,providing good detection efficiency.The customizable strand displacement(SD)probe was used in LAMP to improve the specificity of the method and prevent by-product capture.Detection was based on a sandwich immunoassay.A fluorescence strip reader measured the fluorescence intensity(FI)of the test(T)line and control(C)line.The linear detection range of the strip was 10^(2)–10^(8) colony forming units(CFU)·mL^(-1).The visual limit of detection was 10^(3) CFU·mL^(-1),indicating that the system was ten-fold more sensitive than AuNPs-labelled test strips.ST specificity was analyzed in accordance with agarose gel outputs of polymerase chain reaction(PCR)and SD-LAMP.We detected ST in foods with an acceptable recovery of 85%–110%.The method is rapid,simple,almost equipment-free,and suitable for bacterial detection in foods and for clinical diagnosis.展开更多
Drug target factor complex identification is necessary for evidence based drug discovery. Previous study showed that using small chemical immobilized magnetic nanobeads the chemical target factors were effectively pur...Drug target factor complex identification is necessary for evidence based drug discovery. Previous study showed that using small chemical immobilized magnetic nanobeads the chemical target factors were effectively purified and identified. Here we succeeded to purify the chemical target factor complex, so called cofactor(s). Arginine exhibits a variety of biological activities through a complex and highly regulated set of pathways that remain incompletely understood at both the whole-body and the cellular levels. The aim of this study is to develop and validate effective purification system for arginine target complex. New arginine target protein (arginine interacting factor 4, AIF4) was purified and identified. Using recombinant AIF4 protein and arginine-immobilized magnetic nanobeads, AIF4 cofactor, AIF4-BP1, were purified. Interaction of AIF4 and AIF4-BP1 was detected in arginine-dependent manner, suggesting arginine receptor complex formation. This nanobeads technology is more than 30-fold efficient purification efficient than general purification technology.展开更多
Hydrogels are a class of materials that has the property of injectability and in situ gel formation.This property of hydrogels is manipulated in this study to develop a biomimetic bioresorbable injectable system of al...Hydrogels are a class of materials that has the property of injectability and in situ gel formation.This property of hydrogels is manipulated in this study to develop a biomimetic bioresorbable injectable system of alginate nanobeads interspersed in fibrin network.Alginate nanobeads developed by calcium cross-linking yielded a size of 200e500 nm.The alginate nanobeads fibrin hydrogel was formed using dual syringe apparatus.Characterization of the in situ injectable hydrogel was done by SEM,FTIR and Rheometer.The developed hydrogel showed mechanical strength of 19 kPa which provides the suitable compliance for soft tissue engineering.Cytocompatibility studies using human umbilical cord blood derived mesenchymal stem cells showed good attachment,proliferation and infiltration within the hydrogel similar to fibrin gel.The developed in situ forming hydrogel could be a suitable delivery carrier of stem cells for soft tissue regeneration.展开更多
In this report, a universal protocol for extract-ing genomic DNA from whole blood, saliva, and bacterial culture by using magnetic nanobeads as solid-phase absor-bents was presented. The enrichment of target cells and...In this report, a universal protocol for extract-ing genomic DNA from whole blood, saliva, and bacterial culture by using magnetic nanobeads as solid-phase absor-bents was presented. The enrichment of target cells and ad-sorption of DNA have been functionally integrated onto the surfaces of the carboxyl-modified magnetic nano-beads, and the DNA segments bound on the surface of the beads can be directly used as PCR templates to amplify a target gene. The PCR products were applied to an oligonucleotide array to perform gene typing. The protocol proves to be simple, rapid, biologically and chemically nonhazardous, and promising for the microfabrication of DNA preparation chip.展开更多
为研究海洋中常见致病性弧菌的快速分离富集方法——免疫磁珠法,本文以副溶血弧菌、哈维氏弧菌、创伤弧菌、灿烂弧菌为研究对象,制备纳米免疫磁珠,并通过一系列优化条件,用3M试纸计算捕获率来确定免疫磁珠最佳捕获条件。最后分别对4种...为研究海洋中常见致病性弧菌的快速分离富集方法——免疫磁珠法,本文以副溶血弧菌、哈维氏弧菌、创伤弧菌、灿烂弧菌为研究对象,制备纳米免疫磁珠,并通过一系列优化条件,用3M试纸计算捕获率来确定免疫磁珠最佳捕获条件。最后分别对4种致病性弧菌的不同菌液稀释浓度、对1株目标菌和8株非目标菌、4种混合菌进行捕获,从而评价免疫磁珠的灵敏度、特异性以及抗干扰能力。结果表明,4种磁珠偶联最佳抗体量为300、600、150、150μg。最佳捕获条件:副溶血弧菌免疫磁珠用量3mg,免疫反应45min,磁分离3min,p H 7.4缓冲液体系。哈维氏弧菌免疫磁珠用量3mg,免疫反应45min,磁分离1min,p H 6.0缓冲液体系。创伤弧菌免疫磁珠用量12mg,免疫反应60min,磁分离5min,p H 8.0缓冲液体系。灿烂弧菌免疫磁珠用量6mg,免疫反应30min,磁分离3min,p H 7.4缓冲液体系。在纯培养情况下,4种免疫磁珠灵敏度均达到10 CFU/m L数量级;分别对9株菌进行捕获,对目标菌的捕获率均达到87%以上,对非目标菌的捕获率均低于32%;对4种混合菌进行捕获时,免疫磁珠捕获率不受其它杂菌干扰。本研究证明了该免疫磁珠有较好的灵敏度、特异性和抗干扰能力,且与其它增菌方法相比,大大缩短了时间,具有较好的应用前景。展开更多
There has been a need for rapid detection of Avian Influenza virus (AIV) H5N1 due to it being a potential pandemic threat. Most of the current methods, including culture isolation and PCR, are very sensitive and speci...There has been a need for rapid detection of Avian Influenza virus (AIV) H5N1 due to it being a potential pandemic threat. Most of the current methods, including culture isolation and PCR, are very sensitive and specific but require specialized laboratories and trained personnel in order to complete the tests and are time-consuming. The goal of this study was to design a biosensor that would be able to rapidly detect AIV H5N1 using aptamers as biosensing material and a quartz crystal microbalance (QCM) for transducing method. Specific DNA aptamers against AIV H5N1 were immobilized, through biotin and streptavidin conjugation, onto the gold surface of QCM sensor to capture the target virus. Magnetic nanobeads (150 nm in diameter) were then added as amplifiers considering its large surface/volume ratio which allows for faster movement and a higher target molecule binding rate. The result showed that the captured AIV caused frequency change, and more change was observed when the AIV concentration increased. The nanobead amplification was effective at the lower concentrations of AIV, however, it was not significant when the AIV concentration was 1 HA or higher. The detection limit of the aptasensor was 1 HAU with a detection time of 1 h. The capture of the target virus on to the surface of QCM sensor and the binding of magnetic nanobeads with the virus was confirmed with electron microscopy. Aptamers have unlimited shelf life and are temperature stable which allows this aptasensor to give much more consistent results specifically for in field applications.展开更多
Our previous study showed that prostaglandin J2 (PGJ2) interacting factor (PGJIF) was purified and identified with magnetic nanobeads. Farther analysis of PGJ2 function shows that PGJ2 inhibits cell proliferation and ...Our previous study showed that prostaglandin J2 (PGJ2) interacting factor (PGJIF) was purified and identified with magnetic nanobeads. Farther analysis of PGJ2 function shows that PGJ2 inhibits cell proliferation and rhodamine 123 incorporation. Using PGJ2- immobilized nanobeads, two target proteins were also purified and identified as PGJIF1 and PGJIF2. PGJIF1 genetic analysis showed that PGJIF1 regulates cell proliferation as well as rhodamine 123 incorporation in mitochondria, indicating that PGJIF1 is one of the PGJ2 target proteins. The other target protein, PGJIF2, changes its intracellular localization in PGJ2-dependent manner. Using nanobeads technology, two PGJ2 target factors were purified and identified.展开更多
基金This work was supported by the National Key Research and Development Program of China(2019YFC1606300)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01S174)the Guangdong Academy of Sciences Special Project of Implementing Innovation-Driven Development Capacity Building(2018GDASCX-0401).
文摘Rapid,sensitive,point-of-care detection of pathogenic bacteria is important for food safety.In this study,we developed a novel quantum dot nanobeads-labelled lateral flow immunoassay strip(QBs-labelled LFIAS)combined with strand displacement loop-mediated isothermal amplification(SD-LAMP)for quantitative Salmonella Typhimurium(ST)detection.Quantum dot nanobeads(QBs)served as fluorescence reporters,providing good detection efficiency.The customizable strand displacement(SD)probe was used in LAMP to improve the specificity of the method and prevent by-product capture.Detection was based on a sandwich immunoassay.A fluorescence strip reader measured the fluorescence intensity(FI)of the test(T)line and control(C)line.The linear detection range of the strip was 10^(2)–10^(8) colony forming units(CFU)·mL^(-1).The visual limit of detection was 10^(3) CFU·mL^(-1),indicating that the system was ten-fold more sensitive than AuNPs-labelled test strips.ST specificity was analyzed in accordance with agarose gel outputs of polymerase chain reaction(PCR)and SD-LAMP.We detected ST in foods with an acceptable recovery of 85%–110%.The method is rapid,simple,almost equipment-free,and suitable for bacterial detection in foods and for clinical diagnosis.
文摘Drug target factor complex identification is necessary for evidence based drug discovery. Previous study showed that using small chemical immobilized magnetic nanobeads the chemical target factors were effectively purified and identified. Here we succeeded to purify the chemical target factor complex, so called cofactor(s). Arginine exhibits a variety of biological activities through a complex and highly regulated set of pathways that remain incompletely understood at both the whole-body and the cellular levels. The aim of this study is to develop and validate effective purification system for arginine target complex. New arginine target protein (arginine interacting factor 4, AIF4) was purified and identified. Using recombinant AIF4 protein and arginine-immobilized magnetic nanobeads, AIF4 cofactor, AIF4-BP1, were purified. Interaction of AIF4 and AIF4-BP1 was detected in arginine-dependent manner, suggesting arginine receptor complex formation. This nanobeads technology is more than 30-fold efficient purification efficient than general purification technology.
基金One of the authors R.Jayakumar is grateful to the Department of Biotechnology(DBT),India,for providing fund under the scheme of Nanoscience and Nanotechnology Program(Ref.No.BT/PR 13585/NNT/28/474/2010)One of the author S.Deepthi is thankful to the Council of Scientific and Industrial Research for supporting financially under the CSIR-SRF award no:9/963(0034)2K13-EMR-I.
文摘Hydrogels are a class of materials that has the property of injectability and in situ gel formation.This property of hydrogels is manipulated in this study to develop a biomimetic bioresorbable injectable system of alginate nanobeads interspersed in fibrin network.Alginate nanobeads developed by calcium cross-linking yielded a size of 200e500 nm.The alginate nanobeads fibrin hydrogel was formed using dual syringe apparatus.Characterization of the in situ injectable hydrogel was done by SEM,FTIR and Rheometer.The developed hydrogel showed mechanical strength of 19 kPa which provides the suitable compliance for soft tissue engineering.Cytocompatibility studies using human umbilical cord blood derived mesenchymal stem cells showed good attachment,proliferation and infiltration within the hydrogel similar to fibrin gel.The developed in situ forming hydrogel could be a suitable delivery carrier of stem cells for soft tissue regeneration.
文摘In this report, a universal protocol for extract-ing genomic DNA from whole blood, saliva, and bacterial culture by using magnetic nanobeads as solid-phase absor-bents was presented. The enrichment of target cells and ad-sorption of DNA have been functionally integrated onto the surfaces of the carboxyl-modified magnetic nano-beads, and the DNA segments bound on the surface of the beads can be directly used as PCR templates to amplify a target gene. The PCR products were applied to an oligonucleotide array to perform gene typing. The protocol proves to be simple, rapid, biologically and chemically nonhazardous, and promising for the microfabrication of DNA preparation chip.
文摘为研究海洋中常见致病性弧菌的快速分离富集方法——免疫磁珠法,本文以副溶血弧菌、哈维氏弧菌、创伤弧菌、灿烂弧菌为研究对象,制备纳米免疫磁珠,并通过一系列优化条件,用3M试纸计算捕获率来确定免疫磁珠最佳捕获条件。最后分别对4种致病性弧菌的不同菌液稀释浓度、对1株目标菌和8株非目标菌、4种混合菌进行捕获,从而评价免疫磁珠的灵敏度、特异性以及抗干扰能力。结果表明,4种磁珠偶联最佳抗体量为300、600、150、150μg。最佳捕获条件:副溶血弧菌免疫磁珠用量3mg,免疫反应45min,磁分离3min,p H 7.4缓冲液体系。哈维氏弧菌免疫磁珠用量3mg,免疫反应45min,磁分离1min,p H 6.0缓冲液体系。创伤弧菌免疫磁珠用量12mg,免疫反应60min,磁分离5min,p H 8.0缓冲液体系。灿烂弧菌免疫磁珠用量6mg,免疫反应30min,磁分离3min,p H 7.4缓冲液体系。在纯培养情况下,4种免疫磁珠灵敏度均达到10 CFU/m L数量级;分别对9株菌进行捕获,对目标菌的捕获率均达到87%以上,对非目标菌的捕获率均低于32%;对4种混合菌进行捕获时,免疫磁珠捕获率不受其它杂菌干扰。本研究证明了该免疫磁珠有较好的灵敏度、特异性和抗干扰能力,且与其它增菌方法相比,大大缩短了时间,具有较好的应用前景。
文摘There has been a need for rapid detection of Avian Influenza virus (AIV) H5N1 due to it being a potential pandemic threat. Most of the current methods, including culture isolation and PCR, are very sensitive and specific but require specialized laboratories and trained personnel in order to complete the tests and are time-consuming. The goal of this study was to design a biosensor that would be able to rapidly detect AIV H5N1 using aptamers as biosensing material and a quartz crystal microbalance (QCM) for transducing method. Specific DNA aptamers against AIV H5N1 were immobilized, through biotin and streptavidin conjugation, onto the gold surface of QCM sensor to capture the target virus. Magnetic nanobeads (150 nm in diameter) were then added as amplifiers considering its large surface/volume ratio which allows for faster movement and a higher target molecule binding rate. The result showed that the captured AIV caused frequency change, and more change was observed when the AIV concentration increased. The nanobead amplification was effective at the lower concentrations of AIV, however, it was not significant when the AIV concentration was 1 HA or higher. The detection limit of the aptasensor was 1 HAU with a detection time of 1 h. The capture of the target virus on to the surface of QCM sensor and the binding of magnetic nanobeads with the virus was confirmed with electron microscopy. Aptamers have unlimited shelf life and are temperature stable which allows this aptasensor to give much more consistent results specifically for in field applications.
文摘Our previous study showed that prostaglandin J2 (PGJ2) interacting factor (PGJIF) was purified and identified with magnetic nanobeads. Farther analysis of PGJ2 function shows that PGJ2 inhibits cell proliferation and rhodamine 123 incorporation. Using PGJ2- immobilized nanobeads, two target proteins were also purified and identified as PGJIF1 and PGJIF2. PGJIF1 genetic analysis showed that PGJIF1 regulates cell proliferation as well as rhodamine 123 incorporation in mitochondria, indicating that PGJIF1 is one of the PGJ2 target proteins. The other target protein, PGJIF2, changes its intracellular localization in PGJ2-dependent manner. Using nanobeads technology, two PGJ2 target factors were purified and identified.
