Publications by authors named "Manlin Li"

16 Publications

  • Page 1 of 1

Simultaneous LC-MS/MS bioanalysis of alkaloids, terpenoids, and flavonoids in rat plasma through salting-out-assisted liquid-liquid extraction after oral administration of extract from Tetradium ruticarpum and Glycyrrhiza uralensis: a sample preparation strategy to broaden analyte coverage of herbal medicines.

Anal Bioanal Chem 2021 Sep 31;413(23):5871-5884. Epub 2021 Jul 31.

Institute of Chinese Materia Medica, The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China.

Herbal medicines have historically been practiced in combinatorial way, which achieves therapeutic efficacy by integrative effects of multi-components. Thus, the accurate and precise measurement of multi bioactive components in matrices is inalienable to understanding the metabolism and disposition of herbal medicines. In this study, aiming to provide a strategy that improves analyte coverage, evaluation of six protocols employing sample pretreatment methods- protein precipitation (PPT), liquid-liquid extraction (LLE), sugaring-out-assisted liquid-liquid extraction (SULLE), and salting-out-assisted liquid-liquid extraction (SALLE)- was performed by LC-MS/MS using rat plasma and a mixture of alkaloid (evodiamine, rutaecarpine, dehydroevodiamine), terpenoid (limonin, rutaevin, obacunone), and flavonoid (liquiritin, isoliquiritin, liquiritigenin) standards isolated from Tetradium ruticarpum and Glycyrrhiza uralensis. These protocols were as follows: (1) PPT with methanol, (2) PPT with acetonitrile, (3) LLE with methyl tertiary-butyl ether-dichloromethane, (4) LLE with ethyl acetate-n-butanol, (5) SALLE with ammonium acetate, (6) SULLE with glucose. The results suggested that SALLE produced broader analyte coverage with satisfactory reproducibility, acceptable recovery, and low matrix interference. Then, sample preparation procedure of SALLE, chromatographic conditions, and mass spectrometric parameters were optimized, followed by method validation, showing that good sensitivity (LLOQ ≤ 1 ng mL), linearity (r ≥ 0.9933), precision (RSD ≤ 14.45%), accuracy (89.54~110.87%), and stability could be achieved. Next, the developed method was applied successfully to determine the pharmacokinetic behavior of the nine compounds in rat plasma after intragastric administration with an extract from Tetradium ruticarpum and Glycyrrhiza uralensis (Wuzhuyu-Gancao pair). Based on an extensive review and experiments, a sample preparation procedure that matches with LC-MS/MS technique and can get wider analyte coverage was outlined. The developed SALLE method is rapid, reliable, and suitable for bioanalysis of analytes with diverse polarity, which was expected to be a promising strategy for the pharmacokinetic studies of herbal medicines. Graphical abstract.
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http://dx.doi.org/10.1007/s00216-021-03568-1DOI Listing
September 2021

Chitosan crosslinked with polyamine-co-melamine for adsorption of Hg: Application in purification of polluted water.

Int J Biol Macromol 2021 Jun 30;181:778-785. Epub 2021 Mar 30.

College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, PR China. Electronic address:

A batch experiment was carried out in order to remove Hg from the aqueous solution as well as the polluted water using modified chitosan (CS) with polyamine compounds (triethylenetetramine (TETA), tetraethylenepentamine (TEPA)), and melamine. The obtained polyamine-co-melamine crosslinked CS derivatives (MCS-4N and MCS-5N) were characterized and used as adsorbents. In comparison to the raw CS, the modification significantly promoted the adsorption of Hg ions. The results of the pseudo-second-order kinetic model revealed that pH-dependent derivatives adsorbents achieved the equilibrium state within 12 h. The Langmuir model was best fitted with the Hg adsorption isotherm and showed the highest adsorption capacities of 140.3 and 109.7 mg/g for MCS-4N and MCS-5N, respectively. A slight decrease in the adsorption efficiency of Hg was noticed with the increment of the ionic strength of the solution. However, the studied adsorbents were easily regenerated and presented adequate reusability. The Hg adsorption was regulated by the combined process of coordination reaction and electrostatic attraction as well. The as-prepared polyamine-co-melamine crosslinked CS derivatives were found potential adsorbents for the adsorptive capture of Hg ions from aqueous solutions and polluted waters.
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http://dx.doi.org/10.1016/j.ijbiomac.2021.03.166DOI Listing
June 2021

Traditional uses, phytochemistry, pharmacology, pharmacokinetics and toxicology of the fruit of Tetradium ruticarpum: A review.

J Ethnopharmacol 2020 Dec 3;263:113231. Epub 2020 Aug 3.

Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai R&D Centre for Standardization of Chinese Medicines, 1200 Cailun Road, Shanghai, 201203, China. Electronic address:

Ethnopharmacological Relevance: The fruit of Tetradium ruticarpum (FTR) known as Tetradii fructus or Evodiae fructus (Wu-Zhu-Yu in Chinese) is a versatile herbal medicine which has been prescribed in Chinese herbal formulas and recognized in Japanese Kampo. FTR has been clinically used to treat various diseases such as headache, vomit, diarrhea, abdominal pain, dysmenorrhea and pelvic inflammation for thousands of years.

Aim Of The Review: The present paper aimed to provide comprehensive information on the ethnopharmacology, phytochemistry, pharmacology, pharmacokinetics, drug interaction and toxicology of FTR in order to build up a foundation on the mechanism of ethnopharmacological uses as well as to explore the trends and perspectives for further studies.

Materials And Methods: This review collected the literatures published prior to July 2020 on the phytochemistry, pharmacology, pharmacokinetics and toxicity of FTR. All relevant information on FTR was gathered from worldwide accepted scientific search engines and databases, including Web of Science, PubMed, Elsevier, ACS, ResearchGate, Google Scholar, and Chinese National Knowledge Infrastructure (CNKI). Information was also obtained from local books, PhD. and MSc. Dissertations as well as from Pharmacopeias.

Results: FTR has been used as an herbal medicine for centuries in East Asia. A total of 165 chemical compounds have been isolated so far and the main chemical compounds of FTR include alkaloids, terpenoids, flavonoids, phenolic acids, steroids, and phenylpropanoids. Crude extracts, processed products (medicinal slices) and pure components of FTR exhibit a wide range of pharmacological activities such as antitumor, anti-inflammatory, antibacterial, anti-obesity, antioxidant, insecticide, regulating central nervous system (CNS) homeostasis, cardiovascular protection. Furthermore, bioactive components isolated from FTR can induce drug interaction and hepatic injury.

Conclusions: Therapeutic potential of FTR has been demonstrated with the pharmacological effects on cancer, inflammation, cardiovascular diseases, CNS, bacterial infection and obesity. Pharmacological and pharmacokinetic studies of FTR mostly focus on its main active alkaloids. Further in-depth studies on combined medication and processing approaches mechanisms, pharmacological and toxic effects not limited to the alkaloids, and toxic components of FTR should be designed.
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http://dx.doi.org/10.1016/j.jep.2020.113231DOI Listing
December 2020

circRNA-UBAP2 promotes the proliferation and inhibits apoptosis of ovarian cancer though miR-382-5p/PRPF8 axis.

J Ovarian Res 2020 Jul 20;13(1):81. Epub 2020 Jul 20.

Department of Reproductive Medicine, Reproductive Medical Centre, The First People's Hospital of Yunnan Province, No. 157 Jin Bi Road, Kunming, People's Republic of China.

Objective: circular RNAs (circRNAs) have been reported to be essential regulators of multiple malignant cancers. However, the functions of circRNAs in ovarian cancer need to be further explored. The aim of our study is to explore the role of circRNA-UBAP2 in ovarian cancer and its mechanism.

Results: circRNA-UBAP2 was upregulated in ovarian cancer tissues and cell lines. Knockdown of circRNA-UBAP2 inhibited cell proliferation and promoted cell apoptosis, but circRNA-UBAP2 overexpressed got opposite results. In addition, circRNA-UBAP2 targeted miR-382-5p and downregulated its expression, PRPF8 was a target gene of miR-382-5p. Furthemore, circRNA-UBAP2/miR-382-5p/PRPF8 axis affected the proliferation, apoptosis and cell cycle of ovarian cancer through the mechanism of competing endogenous RNAs (ceRNA).

Conclusion: circRNA-UBAP2 acted as a ceRNA to sponged miR-382-5p, increased the expression level of PRPF8, and prompted proliferation and inhibited apoptosis in ovarian cancer cells.
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http://dx.doi.org/10.1186/s13048-020-00685-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7372761PMC
July 2020

Modification of Rhizosphere Bacterial Community Structure and Functional Potentials to Control Replant Disease.

Plant Dis 2020 Jan 13;104(1):25-34. Epub 2019 Nov 13.

College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China.

Replant disease caused by negative plant-soil feedback commonly occurs in a monoculture regime. Here, barcoded pyrosequencing of 16S ribosomal DNA amplicons combined with phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis was applied to study the shifts in soil bacterial community structure and functional potentials in the rhizosphere of under consecutive monoculture and different soil amendments (i.e., bio-organic fertilizer application [MF] and paddy-upland rotation [PR]). The results showed that the yield of tuberous roots decreased under consecutive monoculture and then increased after MF and PR treatments, which was consistent with the changes in soil bacterial diversity. Both principal coordinate analysis and the unweighted pair-group method with arithmetic means cluster analysis showed the distinct difference in bacterial community structure between the consecutively monocultured soil (relatively unhealthy soil) and other relatively healthy soils (i.e., newly planted soil, MF, and PR). Furthermore, taxonomic analysis showed that consecutive monoculture of significantly decreased the relative abundances of the families Burkholderiaceae and Acidobacteriaceae (subgroup 1), whereas it increased the population density of families Xanthomonadaceae, Phyllobacteriaceae, Sphingobacteriaceae, and Alcaligenaceae, and . In contrast, the MF and PR treatments recovered the soil microbiome and decreased abundance through the different ways; for example, the introduction of beneficial microorganisms (in MF) or the switching between anaerobic and aerobic conditions (in PR). In addition, PICRUSt analysis revealed the higher abundances of membrane transport, cell motility, and DNA repair in the consecutively monocultured soil, which might contribute to the root colonization and survival for certain bacterial pathogens under monoculture. These findings highlight the close association between replant disease of and the variations in structure and potential functions of rhizosphere bacterial community.
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http://dx.doi.org/10.1094/PDIS-04-19-0833-REDOI Listing
January 2020

Polyamine-co-2, 6-diaminopyridine covalently bonded on chitosan for the adsorptive removal of Hg(II) ions from aqueous solution.

Int J Biol Macromol 2019 Jun 3;130:853-862. Epub 2019 Mar 3.

College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, PR China. Electronic address:

In the present study, 2, 6-diaminopyridine (PD) and polyamine compounds (ethylenediamine (EDA), triethylenetetramine (TETA), and tetraethylenepentamine (TEPA)) were used to modify chitosan (CS). The obtained derivatives (PD-CS, PD-EDA-CS, PD-TETA-CS, and PD-TEPA-CS) were identified and employed as adsorbents in batch experiments for the removal of Hg(II) from aqueous solutions. The results confirmed that successful modification improves the Hg(II) adsorption significantly compared to pristine CS. The adsorbed amounts of Hg(II) increased gradually and reached maxima at pH values above 4.0 for all derivatives. The Hg(II) adsorption equilibrium state was achieved within 12 h, with the process driven by a pseudo-second-order kinetic model. The Langmuir model effectively interpreted the Hg(II) adsorption isotherms; the maximum adsorption capacities for Hg(II) ions at 295 K were 172.7, 303.6, 276.0, and 230.6 mg/g for PD-CS, PD-EDA-CS, PD-TETA-CS, and PD-TEPA-CS, respectively. High temperature and low ionic strength favored Hg(II) adsorption. The Hg(II)-loaded CS derivative was easily regenerated and showed acceptable reusability. The further FT-IR and XPS analyses indicate that the Hg(II) adsorption is governed by a process combining electrostatic attraction and a coordination reaction. The CS derivatives produced from polyamine-co-2, 6-diaminopyridine covalently bonded onto CS are promising adsorbents for the adsorptive removal of Hg(II) from an aqueous solution.
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http://dx.doi.org/10.1016/j.ijbiomac.2019.03.007DOI Listing
June 2019

Decontamination of Hg(II) from aqueous solution using polyamine-co-thiourea inarched chitosan gel derivatives.

Int J Biol Macromol 2018 Jul 20;113:106-115. Epub 2018 Feb 20.

College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, PR China. Electronic address:

Ethylenediamine (EDA), triethylenetetramine (TETA) and tetraethylenepentamine (TEPA) had been successfully introduced into the structure of thiourea (TC) modified chitosan (CS) by using formaldehyde as linkage, respectively. The resulted materials, TC-CS, TC-EDA-CS, TC-TETA-CS, and TC-TEPA-CS were characterized and employed as adsorbents in batch experiment for the Hg(II) removal. We have found the modification enhanced the Hg(II) adsorption significantly in comparison with raw CS. Hg(II) adsorption amounts for all adsorbents increased gradually and reached maxima at pH≥4.0. The adsorption of Hg(II) achieved an equilibrium state within 12h with the process drove by the pseudo-second-order model. The ionic strength had no remarkable inhibition effect on Hg(II) adsorption. While the Hg(II) adsorption capacities of the adsorbents were strongly related with the modifier types and the length of the incorporating amino ligands. Langmuir model described Hg(II) adsorption well with the maximum adsorption capacities of prepared adsorbents in order of TC-EDA-CS (217.1mg/g)>TC-CS (164.8mg/g)>TC-TETA-CS (149.7mg/g)>TC-TEPA-CS (140.6mg/g) at room temperature. The FT-IR and XPS investigations implied that Hg(II) ion adsorption mechanism was characterized by a complexation reaction process. Adsorbents could be readily regenerated and had great reusability potential in Hg(II) ions capture from aqueous solution.
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http://dx.doi.org/10.1016/j.ijbiomac.2018.02.101DOI Listing
July 2018

Removal of Cd(II) and Cr(VI) ions by highly cross-linked Thiocarbohydrazide-chitosan gel.

Int J Biol Macromol 2017 Nov 3;104(Pt A):1072-1081. Epub 2017 Jul 3.

College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, PR China.

A highly cross-linked Thiocarbohydrazide-modified chitosan (TCCS) gel was synthesized by using formaldehyde as linkage, and was used in removal of Cd(II) and Cr(VI) from aqueous solution. The results showed that TCCS could be used in a wider pH range and had higher adsorption abilities than raw chitosan for Cd(II) and Cr(VI) ions. The maximum adsorption capacities of the synthetic TCCS for two ions reached 81.26 and 144.68mg/g at 298K, respectively. The endothermic adsorption exhibited pseudo-second-order kinetic behavior and the adsorption isotherm could be well described by Langmuir model. The Cd(II) ion adsorption mechanism was dominated by a complexation reaction process, while the Cr(VI) adsorption was governed by a multiple mechanism including electrostatic attraction, reduction and complexation process. TCCS was easy to be regenerated and had great reusability potential in Cd(II) and Cr(VI) ions capture from aqueous solution.
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http://dx.doi.org/10.1016/j.ijbiomac.2017.07.005DOI Listing
November 2017

A decision analysis model for KEGG pathway analysis.

BMC Bioinformatics 2016 Oct 6;17(1):407. Epub 2016 Oct 6.

College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, People's Republic of China.

Background: The knowledge base-driven pathway analysis is becoming the first choice for many investigators, in that it not only can reduce the complexity of functional analysis by grouping thousands of genes into just several hundred pathways, but also can increase the explanatory power for the experiment by identifying active pathways in different conditions. However, current approaches are designed to analyze a biological system assuming that each pathway is independent of the other pathways.

Results: A decision analysis model is developed in this article that accounts for dependence among pathways in time-course experiments and multiple treatments experiments. This model introduces a decision coefficient-a designed index, to identify the most relevant pathways in a given experiment by taking into account not only the direct determination factor of each Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway itself, but also the indirect determination factors from its related pathways. Meanwhile, the direct and indirect determination factors of each pathway are employed to demonstrate the regulation mechanisms among KEGG pathways, and the sign of decision coefficient can be used to preliminarily estimate the impact direction of each KEGG pathway. The simulation study of decision analysis demonstrated the application of decision analysis model for KEGG pathway analysis.

Conclusions: A microarray dataset from bovine mammary tissue over entire lactation cycle was used to further illustrate our strategy. The results showed that the decision analysis model can provide the promising and more biologically meaningful results. Therefore, the decision analysis model is an initial attempt of optimizing pathway analysis methodology.
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http://dx.doi.org/10.1186/s12859-016-1285-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5053338PMC
October 2016

Removal of Pb(II) and Cd(II) ions from aqueous solution by thiosemicarbazide modified chitosan.

Int J Biol Macromol 2016 May 12;86:876-84. Epub 2016 Feb 12.

College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, PR China.

The removal of Pb(II) and Cd(II) ions from aqueous solution by thiosemicarbazide modified chitosan (TCS) was studied in this article. The synthesized TCS was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), element analysis, N2 adsorption-desorption, scanning electron microscopy (SEM) and X-ray photoelectron spectrophotometer (XPS). Moreover, the influence of solution pH, contact time, initial heavy metal concentration, and solution temperature on the adsorption process was examined, and the adsorbent reusability and adsorption mechanisms were also studied. The results showed that TCS adsorbed greater amount of Pb(II) and Cd(II) ions than the raw chitosan. The adsorption amounts of Pb(II) and Cd(II) ions were affected by increasing solution pH and temperature. The maximum adsorption capacities of the TCS for Pb(II) and Cd(II) ions were found to be 325.2 and 257.2 mg/g, respectively. The endothermic adsorption fitted the pseudo-second-order kinetics equation and the adsorption isotherms could be well described by Langmuir model. The metal ions adsorption mechanism was concluded to be mainly dominated by complexation reaction process. The desorption study indicated that the target adsorbent was easy to be regenerated.
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http://dx.doi.org/10.1016/j.ijbiomac.2016.02.027DOI Listing
May 2016

Simple preparation of aminothiourea-modified chitosan as corrosion inhibitor and heavy metal ion adsorbent.

J Colloid Interface Sci 2014 Mar 26;417:131-6. Epub 2013 Nov 26.

College of Science, Northwest A&F University, Yangling, Shaanxi 712100, PR China. Electronic address:

By a simple and convenient method of using formaldehyde as linkages, two new chitosan (CS) derivatives modified respectively with thiosemicarbazide (TSFCS) and thiocarbohydrazide (TCFCS) were synthesized. The new compounds were characterized and studied by Fourier transform infrared spectroscopy, elemental analysis, thermal gravity analysis and differential scanning calorimetry, and their surface morphologies were determined via scanning electron microscopy. These CS derivatives could form pH dependent gels. The behavior of 304 steel in 2% acetic acid containing different inhibitors or different concentrations of inhibitor had been studied by potentiodynamic polarization test. The preliminary results show that the new compound TCFCS can act as a mixed-type metal anticorrosion inhibitor in some extent; its inhibition efficiency is 92% when the concentration was 60 mg/L. The adsorption studies on a metal ion mixture aqueous solution show that two samples TSFCS and TCFCS can absorb As (V), Ni (II), Cu (II), Cd (II) and Pb (II) efficiently at pH 9 and 4.
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http://dx.doi.org/10.1016/j.jcis.2013.11.053DOI Listing
March 2014

The effect of acetylcholine-like biomimetic polymers on neuronal growth.

Biomaterials 2011 Apr;32(12):3253-64

Colleges of Science and Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China.

Driven by clinical needs, nerve regeneration studies have recently become the focus of research and area of growth in tissue engineering. Biomimetic polymer synthesis and functional interface construction is a promising solution to induce neuritic sprouting and guide the regenerating nerve. However, few studies have been made on primary hippocampal neurons. In this study, a new type of acetylcholine-like biomimetic polymers for their potential in biomaterial-modulated nerve regeneration application is synthesized using click chemistry and free radical polymerization. The structure of the synthesized polymers includes a "bioactive" unit (acetylcholine-like unit) and a "bioinert" unit [poly(ethylene glycol) unit]. To explore the effects of the bioactive unit and the bioinert unit on neuronal growth, different ratios of the two initial monomers poly(ethylene glycol) monomethyl ether-glycidyl methacrylate (MePEG-GMA) and dimethylaminoethyl methacrylate (DMAEMA) were employed and five different polymers were synthesized. Their chemical structures were characterized using (1)H nuclear magnetic resonance and Fourier-transform infrared spectroscopy, and their physical properties (including molecular weight, polydispersity, glass transition temperature, and melting point) were determined using gel permeation chromatography and differential scanning calorimetry. Culturing of the primary rat hippocampal neurons on the polymeric surfaces show that the ratio of the two initial monomers utilized for polymer synthesis significantly affects neuronal growth. Rat hippocampal neurons show different growth morphologies on different polymeric surfaces. The polymeric surface prepared with 1:60 (mol/mol) of MePEG-GMA to DMAEMA induces neuronal regenerative responses similar to that on poly-l-lysine, a very common benchmark material for nerve cell cultures. These results suggest that acetylcholine-like biomimetic polymers are potential biomaterials for neural engineering applications, particularly in modulating the growth of hippocampal neurons.
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http://dx.doi.org/10.1016/j.biomaterials.2011.01.044DOI Listing
April 2011

Magnetic protein microbead-aided indirect fluoroimmunoassay for the determination of canine virus specific antibodies.

Biosens Bioelectron 2011 Mar 22;26(7):3353-60. Epub 2011 Jan 22.

College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, PR China.

Rabies, canine distemper, and canine parvovirus are common contagious viral diseases of dogs and many other carnivores, and pose a severe threat to the population dynamics of wild carnivores, as well as endangering carnivore conservation. However, clinical diagnosis of these diseases, especially canine distemper and canine parvovirus, is difficult because of the broad spectrum of symptoms that may be confused with other respiratory and enteric diseases of dogs. The most frequently used and proven techniques for diagnosing viral diseases include the conventional enzyme-linked immunosorbent assay (ELISA), rapid fluorescent focus inhibition test (RFFIT), mouse neutralisation test (MNT), and fluorescent antibody virus neutralization (FAVN) test. However, these methods still have some inherent limitations. In this study, a magnetic protein microbead-aided indirect fluoroimmunoassay was developed to detect canine virus specific antibodies, human rabies immunoglobulin, CDV McAbs, and CPV McAbs. In this assay, an avidin-biotin system was employed to combine magnetic microbeads and virus antigens (rabies virus, canine distemper virus, and canine parvovirus). Quantification of the targeted virus antibodies was analyzed through indirect fluoroimmunoassay using the specific antigen-antibody reaction, as well as their corresponding FITC-labeled detection antibodies (mouse anti-human IgG/FITC conjugate or rabbit anti-dog IgG/FITC conjugate). The results indicated that the fluorescence intensity increased when a higher concentration of the targeted analyte was used, but the control had almost no fluorescence, much like the conventional ELISA. For human rabies immunoglobulin, CDV McAbs, and CPV McAbs, the minimum detectable concentrations were 0.2 IU/mL, 0.3 ng/mL, and 0.5 ng/mL, respectively. All of these results indicate that this assay can be employed to determine the presence of canine virus specific antibodies. In addition, the method devised here can be utilized as a general protocol in other bacterial and viral marker analysis.
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http://dx.doi.org/10.1016/j.bios.2011.01.018DOI Listing
March 2011

Conjugation of biomolecules with magnetic protein microspheres for the assay of early biomarkers associated with acute myocardial infarction.

Anal Chem 2009 Aug;81(15):6210-7

College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, P.R. China.

This study demonstrates an improved magnetic protein microsphere-aided sandwich fluoroimmunoassay for the analysis of myoglobin and heart-type fatty acid binding protein (H-FABP), early protein markers associated with acute myocardial infarction. In preparation for the assay we constructed superparamagnetic human serum albumin (HSA)/gamma-Fe(2)O(3) microspheres, and grafted capture antibodies (monoclonal antimyoglobin 7C3 and anti-H-FABP 10E1) onto the protein microspheres using the avidin-biotin system. Then the antibody-carrying microspheres were used in a sequential sandwich fluoroimmunoassay along with detection antibodies (Alexa fluor594-labeled antimyoglobin 4E2 and FITC-labeled anti-H-FABP 9F3). The magnetic HSA/gamma-Fe(2)O(3) microspheres were characterized by scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectrophotometry, atomic absorption spectrophotometry, and vibrating sample magnetometry. Fluorescence images of the post-immunoassay microspheres recorded using an inverted fluorescence microscope showed that the average fluorescence intensity was correlated with the concentration of cardiac markers, in agreement with the results obtained by an F-4500 FL spectrophotometer; this indicated that the fluoroimmunoassay could be used to semiquantitatively detect both myoglobin and H-FABP. The detection limit was 10 ng/mL for myoglobin and 1 ng/mL for H-FABP.
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http://dx.doi.org/10.1021/ac9007418DOI Listing
August 2009

Carboxylated magnetic microbead-assisted fluoroimmunoassay for early biomarkers of acute myocardial infarction.

Colloids Surf B Biointerfaces 2009 Aug 2;72(1):112-20. Epub 2009 Apr 2.

College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, PR China.

A carboxylated superparamagnetic microbead-assisted sandwich fluoroimmunoassay was successfully demonstrated for the analysis of the early protein markers, myoglobin and human heart-type fatty acid-binding protein (H-FABP), associated with acute myocardial infarction. This assay approach consisted of the preparation of superparamagnetic polymer microbeads using a dispersion polymerization, followed by grafting of capture antibodies (monoclonal anti-H-FABP 10E1 and anti-myoglobin 7C3) onto the polymer microbeads using EDC-NHS protocol, and then a sequential sandwich fluoroimmunoassay using detection antibodies (FITC-labeled anti-H-FABP 9F3 and FITC-labeled anti-myoglobin 4E2). The Fe(3)O(4) nanoparticles and carboxylated Fe(3)O(4)-polymer microbeads were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrophotometry, vibrating sample magnetometry, and X-ray diffraction. The fluoroimmunoassay images were recorded using a confocal laser-scanning microscope, and the average fluorescence intensity of the microbeads was found to correspond to the concentration of each cardiac marker, in agreement with the results obtained by a spectrofluorophotometer. The carboxylated magnetic microbead-assisted protocol could be utilized to semi-quantitatively detect both myoglobin and H-FABP.
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http://dx.doi.org/10.1016/j.colsurfb.2009.03.023DOI Listing
August 2009

Superparamagnetic microsphere-assisted fluoroimmunoassay for rapid assessment of acute myocardial infarction.

Biosens Bioelectron 2009 Jun 2;24(10):3097-102. Epub 2009 Apr 2.

College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China.

Rapid assessment of acute myocardial infarction (AMI) was successfully demonstrated using an improved superparamagnetic polymer microsphere-assisted sandwich fluoroimmunoassay to detect two early cardiac markers-myoglobin and human heart-type fatty acid binding protein (H-FABP). This assay used a preparation of superparamagnetic poly(styrene-divinylbenzene-acrylamide) microspheres, glutaraldehyde-coupled capture antibodies (monoclonal anti-myoglobin 7C3 and anti-H-FABP 10E1) grafted onto the polymer microspheres, and a sequential sandwich fluoroimmunoassay using detection antibodies (FITC-labeled anti-myoglobin 4E2 and FITC-labeled anti-H-FABP 9F3). Characterization of the polymer microspheres by TEM, SEM and Fourier transform infrared spectroscopy (FT-IR) showed that the microspheres were uniformly round with an average diameter of 1.12 microm, and had a Fe(3)O(4)-polymer core-shell structure (shell thickness was about 84 nm) with 0.22 mmol/g amino groups on their surfaces. The magnetic behavior of the Fe(3)O(4)-polymer microspheres was superparamagnetic (M(s)=13 emu/g, H(c)=13.1 Oe). Fluorescence images of the post-immunoassay microspheres recorded using a confocal laser-scanning microscope showed that the average fluorescence intensity was correlated with the concentration of cardiac markers, in agreement with the results obtained by an F-4500 FL spectrophotometer; this indicated that the fluoroimmunoassay could be used to semi-quantitatively detect both myoglobin and H-FABP. The detection limit was 25 ng/mL for myoglobin and 1 ng/mL for H-FABP.
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http://dx.doi.org/10.1016/j.bios.2009.03.033DOI Listing
June 2009
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