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1.
Journal of Forensic Medicine ; (6): 168-175, 2023.
Artículo en Inglés | WPRIM | ID: wpr-981851

RESUMEN

Given the complexity of biological samples and the trace nature of target materials in forensic trace analysis, a simple and effective method is needed to obtain sufficient target materials from complex substrates. Magnetic nanoparticles (MNPs) have shown a wide range of application value in many research fields, such as biomedicine, drug delivery and separation, due to their unique superparamagnetic properties, stable physical and chemical properties, biocompatibility, small size, high specific surface area and other characteristics. To apply MNPs in the pretreatment of forensic materials, maximize the extraction rate of the target materials, and minimize interference factors to meet the requirements of trace analysis of the target materials, this paper reviews the application of MNPs in the fields of forensic toxicological analysis, environmental forensic science, trace evidence analysis and criminal investigation in recent years, and provides research ideas for the application of MNPs in forensic trace analysis.


Asunto(s)
Nanopartículas de Magnetita/química , Medicina Legal , Ciencias Forenses , Toxicología Forense
2.
Journal of Preventive Medicine ; (12): 855-860, 2022.
Artículo en Chino | WPRIM | ID: wpr-936809

RESUMEN

Objective@# To develop a magnetic solid-phase extraction combined with gas chromatography-tandem mass spectrometry (GC-MS/MS) based on pyrrole-modified magnetic nanoparticles to determine 16 types of phthalic acid esters (PAEs) in commercial liquors.@*Methods @#Fe3O4 magnetic nuclei were prepared by hydrothermal synthesis, and the polypyrrole-modified magnetic nanomaterials were prepared with the chemical oxidation method. Magnetic solid-phase extraction of beer, grape wine, rice wine and Chinese spirits was performed at 10% alcohol by volume, extraction duration of 20 min and ethyl acetate elution of 10 min, followed by addition of 1 g NaCl for reduction of emulsification effect. The 16 types of PAEs were determined using GC-MS/MS with DB-5MS capillary column (30 m×250 μm, 0.25 μm) under the mode of electron impact ionization (EI) and dynamic multiple reaction monitoring (dMRM), with quantitative analysis using the external standard method. The standard curve, detection limit, spike recovery rate and precision of GC-MS/MS for determination of 16 types of PAEs were evaluated.@*Results@#Pyrrole was successfully embedded onto the surface of magnetic nanoparticles in the form of polymer, and the magnetic nanoparticles modified by polypyrrole were well characterized, showing unapparent matrix and emulsification effects. There was a good linear relationship for the 16 types of PAEs at 50 to 5 000 ng/mL (r=0.999 5-0.999 9), and the spike recovery rate of 16 types of PAEs ranged from 71.61% to 110.50% at 100, 500 and 1 000 μg/kg, with relative standard deviations of 3.78% to 7.41%, detection limits of 0.02 to 1.47 μg/kg. PAEs were detected in 20 out of 50 liquor samples, with 30.00%, 60.00%, 40.00% and 70.00% detection rates in beer, grape wine, rice wine and Chinese spirits, respectively. @*Conclusions@#This method is sensitive to determine 16 types of PAEs in liquor samples, with unapparent matrix and emulsification effects, and the polypyrrole-modified magnetic composite nanoparticles present high adsorption of PAEs in liquor samples, which is feasible for monitoring of PAEs in multiple types of liquor samples.

3.
Journal of Zhejiang University. Medical sciences ; (6): 102-107, 2022.
Artículo en Inglés | WPRIM | ID: wpr-928654

RESUMEN

Magnetic nanoparticles (MNP) have been widely used as biomaterials due to their unique magnetic responsiveness and biocompatibility, which also can promote osteogenic differentiation through their inherent micro-magnetic field. The MNP composite scaffold retains its superparamagnetism, which has good physical, mechanical and biological properties with significant osteogenic effects and . Magnetic field has been proved to promote bone tissue repair by affecting cell metabolic behavior. MNP composite scaffolds under magnetic field can synergically promote bone tissue repair and regeneration, which has great application potential in the field of bone tissue engineering. This article summarizes the performance of magnetic composite scaffold, the research progress on the effect of MNP composite scaffold with magnetic fields on osteogenesis, to provide reference for further research and clinical application.


Asunto(s)
Diferenciación Celular , Nanopartículas de Magnetita , Osteogénesis , Ingeniería de Tejidos , Andamios del Tejido
4.
International Journal of Biomedical Engineering ; (6): 73-79,85, 2022.
Artículo en Chino | WPRIM | ID: wpr-954195

RESUMEN

Theranotics, an integrated diagnosis and treatment nanoplatform technology based on nanomaterials, integrates the diagnosis and treatment of diseases seamlessly and shows a broad prospect in medical practice. With the rapid development of nanomedicine, the technology of magnetic nanoparticles (MNPs) synthesis is becoming more and more mature. MNPs have controllable shape and particle size, admirable stability and biocompatibility, excellent magnetic properties, and can be readily chemically modified. These advantages make them widely used in clinical practice, such as diagnosis, targeted drug delivery, medical imaging, hyperthermia therapy, and radiotherapy, which also make MNPs high-quality materials for integrated diagnosis and treatment platforms.In this paper, the research progress of MNPs in the areas of magnetically guided drug delivery, magnetic thermotherapy, and multimodal imaging was reviewed; their advantages as an integrated platform for diagnosis and treatment were discussed; and the problems faced in research and application prospects were summarized and outlooked.

5.
Braz. j. biol ; 82: 1-10, 2022. tab, ilus
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1468553

RESUMEN

Enzymes immobilized onto substrates with excellent selectivity and activity show a high stability and can withstand extreme experimental conditions, and their performance has been shown to be retained after repeated uses. Applications of immobilized enzymes in various fields benefit from their unique characteristics. Common methods, including adsorption, encapsulation, covalent attachment and crosslinking, and other emerging approaches (e.g., MOFs) of enzyme immobilization have been developed mostly in recent years. In accordance with these immobilization methods, the present review elaborates the application of magnetic separable nanoparticles and functionalized SBA-15 and MCM-41 mesoporous materials used in the immobilization of enzymes.


Enzimas imobilizadas em substratos com excelente seletividade e atividade apresentam alta estabilidade e podem suportar condições experimentais extremas, e seu desempenho foi mantido após repetidos usos. As aplicações de enzimas imobilizadas em vários campos se beneficiam de suas características únicas. Métodos comuns, incluindo adsorção, encapsulamento, ligação covalente e reticulação, e outras abordagens emergentes (por exemplo, MOFs) de imobilização de enzima, foram desenvolvidos principalmente nos últimos anos. De acordo com esses métodos de imobilização, a presente revisão elabora a aplicação de nanopartículas magnéticas separáveis e materiais mesoporosos funcionalizados SBA-15 e MCM-41 usados na imobilização de enzimas.


Asunto(s)
Agentes de Inmovilización de Enzimas , Nanopartículas
6.
Braz. j. biol ; 822022.
Artículo en Inglés | LILACS-Express | LILACS, VETINDEX | ID: biblio-1468740

RESUMEN

Abstract Enzymes immobilized onto substrates with excellent selectivity and activity show a high stability and can withstand extreme experimental conditions, and their performance has been shown to be retained after repeated uses. Applications of immobilized enzymes in various fields benefit from their unique characteristics. Common methods, including adsorption, encapsulation, covalent attachment and crosslinking, and other emerging approaches (e.g., MOFs) of enzyme immobilization have been developed mostly in recent years. In accordance with these immobilization methods, the present review elaborates the application of magnetic separable nanoparticles and functionalized SBA-15 and MCM-41 mesoporous materials used in the immobilization of enzymes.


Resumo Enzimas imobilizadas em substratos com excelente seletividade e atividade apresentam alta estabilidade e podem suportar condições experimentais extremas, e seu desempenho foi mantido após repetidos usos. As aplicações de enzimas imobilizadas em vários campos se beneficiam de suas características únicas. Métodos comuns, incluindo adsorção, encapsulamento, ligação covalente e reticulação, e outras abordagens emergentes (por exemplo, MOFs) de imobilização de enzima, foram desenvolvidos principalmente nos últimos anos. De acordo com esses métodos de imobilização, a presente revisão elabora a aplicação de nanopartículas magnéticas separáveis e materiais mesoporosos funcionalizados SBA-15 e MCM-41 usados na imobilização de enzimas.

7.
Braz. j. biol ; 82: e244496, 2022. tab, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1278474

RESUMEN

Enzymes immobilized onto substrates with excellent selectivity and activity show a high stability and can withstand extreme experimental conditions, and their performance has been shown to be retained after repeated uses. Applications of immobilized enzymes in various fields benefit from their unique characteristics. Common methods, including adsorption, encapsulation, covalent attachment and crosslinking, and other emerging approaches (e.g., MOFs) of enzyme immobilization have been developed mostly in recent years. In accordance with these immobilization methods, the present review elaborates the application of magnetic separable nanoparticles and functionalized SBA-15 and MCM-41 mesoporous materials used in the immobilization of enzymes.


Enzimas imobilizadas em substratos com excelente seletividade e atividade apresentam alta estabilidade e podem suportar condições experimentais extremas, e seu desempenho foi mantido após repetidos usos. As aplicações de enzimas imobilizadas em vários campos se beneficiam de suas características únicas. Métodos comuns, incluindo adsorção, encapsulamento, ligação covalente e reticulação, e outras abordagens emergentes (por exemplo, MOFs) de imobilização de enzima, foram desenvolvidos principalmente nos últimos anos. De acordo com esses métodos de imobilização, a presente revisão elabora a aplicação de nanopartículas magnéticas separáveis e materiais mesoporosos funcionalizados SBA-15 e MCM-41 usados na imobilização de enzimas.


Asunto(s)
Enzimas Inmovilizadas/metabolismo , Nanopartículas de Magnetita , Estabilidad de Enzimas , Adsorción , Concentración de Iones de Hidrógeno
8.
Chinese Traditional and Herbal Drugs ; (24): 4142-4150, 2020.
Artículo en Chino | WPRIM | ID: wpr-846226

RESUMEN

Objective: To achieve multiple target fishing hook by efficiently grafting polymers containing benzophenone (BP) groups and photochemically coupling molecules in medicines onto magnetic nanoparticles (MNPs). Methods: MNPs attached carbonyl groups (Fe3O4-COOH) were prepared through a hydrothermal process. Then they were modified with DMSA, forming MNPs with thiol groups (Fe3O4-SH). Fe3O4-SH nanoparticles were grafted with polymer containing BP groups by surface-initiated condensation polymerization. Effects of monomer feed ratios and contents on the amounts of BP groups were investigated. The molecules in medicines were covalently coupled onto MNPs via photochemical reactions of BP groups. The contents of coupled molecules were determined by FT-IR and UV-Vis spectra analyses. Results: MNPs with average size of 100 nm were produced, modified with DMSA, and decorated by grafting polymer containing photosensitive BP groups. When the content of monomer containing BP groups was increased in grafting polymerizations, more BP groups were incorporated onto MNPs. This was conductive to the subsequent photo- coupling. FT-IR and UV-Vis spectra analyses confirmed the coupling of molecules in medicines. The active H and steric hinderance of the molecules affected their coupling. Conclusion: The resultant magnetic target fishing hook is ready as a probe for targets identification of traditional Chinese medicine (TCM).

9.
Journal of China Pharmaceutical University ; (6): 531-539, 2019.
Artículo en Chino | WPRIM | ID: wpr-807894

RESUMEN

@#With the rapid development of nanotechnology, accurate personalized treatments for tumor have attracted more attention to increase the therapeutic effects and reduce the side effects. The emerging theranostic systems incorporating different therapeutic and diagnostic imaging capabilities have become a new research hotspot. Magnetic iron oxide nanoparticles(IONP)have been widely used in theranostic systems due to their unique imaging properties, stable thermal performance, excellent biocompatibility and admirable surface modifiability. In this review, we analyzed the advantages of IONP in the diagnosis and the treatment of tumor, and detailedly introduced the relevant strategies and latest research progress, including magnetic resonance imaging(MRI), photothermal therapy, magnetic hyperthermia, and magnetic targeted drug delivery, etc. Finally, the potential application of IONP in the clinical tumor theranostics was proposed.

10.
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery ; (12): 691-695, 2018.
Artículo en Chino | WPRIM | ID: wpr-732660

RESUMEN

@#Objective    To explore the diagnostic value of circulating tumor cells (CTC) measured by magnetic nanoparticle method in lung cancer. Methods    (1) We measured binding capability of A549 or NCI-H1965 cell lines with recognition peptide and capture efficiency by adding tumor cells into the whole blood of healthy human. (2) We measured CTC of 34 patients suspected with lung cancer, and the counting results of CTC were compared with the following pathological results. Results    (1) The binding capability was 80.0%±6.0% for A549 and 70.1%±4.8% for H1957, while the capture efficiency was 57.3%±7.0% for A549 and 37.3%±6.1% for H1975. (2) CTCs were identified in 71.9% of patients with lung cancer. The specificity was 83.3%, and area under receiver operating characteristic (ROC) curve was 0.792 (P=0.003). Conclusion    CTC measured by magnetic nanoparticle method has promising application in the diagnosis of lung cancer.

11.
Academic Journal of Second Military Medical University ; (12): 68-73, 2018.
Artículo en Chino | WPRIM | ID: wpr-838231

RESUMEN

Objective To evaluate the performance of magnetic nanoparticle chemiluminescence immunoassay (NM-CLIA) in detection of allergen-specific immunoglobulin E (sIgE) antibodies to Dermatophagoides pteronyssinus (International Allergen Code D1) and Dermatophagoides farinae (International Allergen Code D2). Methods A total of 489 serum samples from the patients with suspected allergic disease (244 cases caused by D1, and 245 caused by D2), who were treated at Suzhou Kowloon Hospital, Shanghai Jiaotong University School of Medicine, were detected by NM-CLIA and immunofluorescence assay, respectively. χ2 test and Kappa test were used to evaluate the correlation between the two methods in detection of D1 and D2 sIgE antibodies. The limit of detection (LoD), linear range and precision of NM-CLIA in detection of D1 and D2 sIgE antibodies were verified by the standard method of American Clinical Laboratory Standardization Association. Results The LoDs of NM-CLIA in detecting D1 and D2 sIgE antibodies were both less than 0.01 U/mL, the linearity ranged from 0.1 to 100 U/mL, the within-run precision was less than 5%, and the between-run precision was less than 8%. Methodological comparison results showed that NM-CLIA and immunofluorescence assay had good consistency in detecting D1 and D2 sIgE antibodies. For D1, the positive coincidence rate and negative coincidence rate were 95% and 92%, respectively (χ2=174.45, P0.001, Kappa=0.843), and the ±1 class agreement was 95.6%; for D2, the positive coincidence rate and negative coincidence rate were 91% and 97%, respectively (χ2=154.263,P0.001,Kappa=0.787), and the ±1 class agreement was 94.2%. Conclusion NM-CLIA has good correlation with immunofluorescence assay in detecting D1 and D2 sIgE antibodies, and has good LoD, linear range and precision, suggesting that it can be recommended for clinical testing of D1 and D2 sIgE antibodies.

12.
Chinese Traditional and Herbal Drugs ; (24): 1041-1047, 2018.
Artículo en Chino | WPRIM | ID: wpr-852136

RESUMEN

Objective: To improve the screening efficiency of the active ingredients in natural products by building up a kind of novel and efficient magnetic nanoparticle-assisted cell membranes (MN-CMs) fishing assay employing specific affinity interactions between active ingredients and receptors on cell membranes (CMs). Methods: The magnetic nanoparticles (MNPs) were combined with erythrocyte membrane of rabbits to fish active ingredients from water extracts of Angelica sinensis, and the fishing results were analyzed by GC-MS. Results: The particle size of the self-made magnetic beads was about (250.6 ± 3.3) nm (n = 3) with PDI index at 0.010 ± 0.003 (n = 3), and the beads were monodisperse, strongly magnetic and superparamagnetic, the saturation magnetization was 83.4 emu/g. The combination of MNPs and CMs was stable, the maximum combined amount was 1.02 mg CMs/10 mg MNPs, and the combination was able to keep better enzyme activity of CMs in the fishing assay. GC-MS results showed that ligustilide was fished out as the active compound from water extracts of A. sinensis by MN-CMs assay with the retention time at 20 min, and the new established fishing assay could effectively avoid the interference of inactive components. Conclusion: Ligustilide, one of the active ingredients in A. sinensis, can be screened out by the established fishing assay of MN-CMs. The developed fishing method in this workmakes up for some deficiencies of traditional screening method and provides a novel and efficient way to screen ingredients from natural products.

13.
Chinese Pharmaceutical Journal ; (24): 1394-1404, 2016.
Artículo en Chino | WPRIM | ID: wpr-859007

RESUMEN

OBJECTIVE: To prepare a kind of novel multifunctional gold nanoshell coated magnetic nanoparticles and investigate their morphology, size distribution, two-photon optical properties, cellular uptake behavior, cytotoxicity as well as drug release profile. METHODS: In this study, the gold shell coated magnetic polyester nanoparticles (AuMPn) were prepared by emulsion solvent evaporation method combined with hydroxylamine reduction method. The size distribution, morphology, and two-photon optical properties were characterized by Zeta sizer, AFM, TEM and multiphoton confocal laser scanning microscopy respectively. The drug loading and release profile were evaluated by dialysis method using idarubicin as a model drug. RESULTS: The resultant AuMPn exhibit spherical shaped morphology with average size of (235.7±1.34) nm. The encapsulation efficiency and drug loading efficiency were 72.08% and 1.73% respectively. Under near infrared light irradiation, gold shell outside of AuMPn showed fingerprint like characteristic emission spectrum. The in vitro drug release study demonstrated that the release of idarubicin from AuMPn can be controlled by NIR irradiation. CONCLUSION: Overall, a novel gold shell coated nanoparticles are successfully prepared in this study. By taking advantage of the dual function of the gold shell outside of the particles, precise control on drug release as well as label-free visualization of AuMPn can be achieved simultaneously. Thus, this approach provides a new strategy for drug delivery.

14.
Chinese Pharmaceutical Journal ; (24): 1893-1898, 2015.
Artículo en Chino | WPRIM | ID: wpr-859317

RESUMEN

OBJECTIVE: To prepare PLGA magnetic nanoparticles loaded with tetrandrine, heat the nanoparticles by inductive heating system, and study the particle size, morphology and drug release before and after heating. METHODS: Co-loaded PLGA NPs were prepared by emulsion solvent diffusion method; the physicochemical and magnetic characteristics of co-loaded PLGA NPs were investigated by DLS, SEM, TEM and VSM; RP-HPLC and ICP-MS analysis were used to measure the tetrandrine and Fe3O4 loading and entrapment efficiency. The EASYHEAT system was applied to heat the nanoparticles and further investigate the changes of particle size, morphology and drug release after inductive heating. RESULTS: Tetrandrine-loaded PLGA magnetic nanoparticles showed spherical shape with smooth surface and the Fe3O4 NPs were homogeneously distributed inside the polymeric nanoparticles; VSM result indicated that the co-loaded PLGA NPs were superparamagnetic; both tetrandrine and Fe3O4 showed good loading and entrapment efficiency. After being heated to 45℃, the diameter of co-loaded PLGA NPs increased; the morphology changed from a spherical shape into a nondefined, irregular shape; arrangement or aggregation of the incorporated Fe3O4 NPs were found. In addition, the drug release amount was also increased. CONCLUSION: With superparamagnetic property, the tetrandrine loaded-PLGA magnetic nanoparticles can effectively control the drug release behavior by inductive heating.

15.
Journal of Veterinary Science ; : 431-437, 2015.
Artículo en Inglés | WPRIM | ID: wpr-207362

RESUMEN

Monoclonal anti-enrofloxacin antibody was prepared for a direct competitive enzyme-linked immunosorbent assay (ELISA) and purification system using monoclonal antibody (mAb) coupled magnetic nanoparticles (MNPs). The IC50 values of the developed mAb for enrofloxacin (ENR), ciprofloxacin, difloxacin, sarafloxacin, pefloxacin, and norfloxacin were 5.0, 8.3, 9.7, 21.7, 36.0, and 63.7 ng/mL, respectively. The lowest detectable level of ENR was 0.7 ng/mL in the prepared ELISA system. To validate the developed ELISA in the food matrix, known amounts of ENR were spiked in meat and egg samples at 10, 20 and 30 ng/mL. Recoveries for ENR ranged from 72.9 to 113.16% with a coefficient of variation (CV) of 2.42 to 10.11%. The applicability of the mAb-MNP system was verified by testing the recoveries for ENR residue in three different matrices. Recoveries for ENR ranged from 75.16 to 86.36%, while the CV ranged from 5.08 to 11.53%. Overall, ENR-specific monoclonal antibody was prepared and developed for use in competitive to ELISAs for the detection of ENR in animal meat samples. Furthermore, we suggest that a purification system for ENR using mAb-coupled MNPs could be useful for determination of ENR residue in food.


Asunto(s)
Animales , Ciprofloxacina , Ensayo de Inmunoadsorción Enzimática , Concentración 50 Inhibidora , Carne , Nanopartículas , Norfloxacino , Óvulo , Pefloxacina
16.
Chinese Journal of Analytical Chemistry ; (12): 1580-1585, 2014.
Artículo en Chino | WPRIM | ID: wpr-459558

RESUMEN

ThemagneticFe3O4nanoparticlesweresynthesizedbyco-precipitationmethod,andthenmagnetic Fe3 O4@Au nanoparticle was synthesized to improve the affinity of particle surface. L-Cys-GA3 was grafted on the surface of gold clad by self-assembly method, and then dropped it on glassy carbon electrode, for further manufacture of MIP/Fe3 O4@Au by using electropolymerzation L-Cys. The surface morphology and particle size distribution of Fe3 O4@Au were studied by TEM. The structure and composition of gibberellins A3, MIP and nMIP were studied by IR. The test system was optimized, and the results showed that when the cycles of electropolymerization was 30, acetic acid:methanol (1:8, V/V) was chosen as eluent, elution time was optimized for 5 min and rebinding time for 7 min, the sensor got a high stability and good recognition ability for gibberellins A3 . The concentration of gibberellins A3 in the range of 1 . 0 × 10-11-1 . 0 × 10-8 mol/L had a relationship with the oxidation peak current of probe, with the detection limit of 2. 57×10-12 mol/L. The sensor was successfully used for the determination of GA3 in beer sample.

17.
Electron. j. biotechnol ; 16(6): 10-10, Nov. 2013. ilus, tab
Artículo en Inglés | LILACS | ID: lil-696551

RESUMEN

Background: Cyclodextrin glycosyltransferase (CGTase) from Amphibacillus sp. NPST-10 was successfully covalently immobilized on aminopropyl-functionalized silica coated superparamagnetic nanoparticles; and the properties of immobilized enzyme were investigated. The synthesis process included preparing of core magnetic magnetite (Fe3O4) nanoparticles using solvothermal synthesis; followed by coating of Fe3O4 nanoparticles with dense amino-functionalized silica (NH2-SiO2) layer using in situ functionalization method. The structure of synthesized Fe3O4@NH2-SiO2 nanoparticles was characterized using TEM, XRD, and FT-IR analysis. Fe3O4@NH2-SiO2 nanoparticles were further activated by gluteraaldehyde as bifunctional cross linker, and the activated nanoparticles were used for CGTase immobilization by covalent attachment. Results: Magnetite nanoparticles was successfully synthesized and coated with and amino functionalized silica layer (Fe3O4/NH2-SiO2), with particle size of 50-70 nm. The silica coated magnetite nanoparticles showed with saturation magnetization of 65 emug-1, and can be quickly recovered from the bulk solution using an external magnet within 10 sec. The activated support was effective for CGTase immobilization, which was confirmed by comparison of FT-IR spectra of free and immobilized enzyme. The applied approach for support preparation, activation, and optimization of immobilization conditions, led to high yields of CGTase immobilization (92.3%), activity recovery (73%), and loading efficiency (95.2%); which is one of the highest so far reported for CGTase. Immobilized enzyme showed shift in the optimal temperature from 50 to 55ºC, and significant enhancement in the thermal stability compared with free enzyme. The optimum pH for enzyme activity was pH 8 and pH 7.5 for free and immobilized CGTase, respectively, with slight improvement of pH stability of immobilized enzyme. Furthermore, kinetic studies revealed that immobilized CGTase had higher affinity toward substrate; with k m values of 1.18 ± 0.05 mg/ml and 1.75 ± 0.07 mg/ml for immobilized and free CGTase, respectively. Immobilized CGTase retained 87% and 67 of its initial activity after 5 and 10 repeated batches reaction, indicating that immobilized CGTase on Fe3O4/NH2-SiO2 had good durability and magnetic recovery. Conclusion: The improvement in kinetic and stability parameters of immobilized CGTase makes the proposed method a suitable candidate for industrial applications of CGTase. To best of our knowledge, this is the first report about CGTase immobilization on silica coated magnetite nanoparticles.


Asunto(s)
Enzimas Inmovilizadas/metabolismo , Enzimas Inmovilizadas/química , Nanopartículas de Magnetita/química , Glucosiltransferasas/metabolismo , Glucosiltransferasas/química , Espectrofotometría Infrarroja , Temperatura , Bacillaceae/enzimología , Cinética , Dióxido de Silicio , Ciclodextrinas , Técnicas de Cultivo , Glucosiltransferasas/aislamiento & purificación , Glucosiltransferasas/biosíntesis , Concentración de Iones de Hidrógeno
18.
Journal of Veterinary Science ; : 363-369, 2012.
Artículo en Inglés | WPRIM | ID: wpr-202784

RESUMEN

In this study, we developed a novel tool for purifying two mycotoxins, aflatoxin B1 (AFB1) and zearalenone (ZEN), in feed. This system utilized monoclonal antibodies (mAbs) against AFB1 and ZEN, and magnetic nanoparticles (MNPs). Among ten MNPs with different diameters and functional groups, a 100-nm diameter MNP (fMA) conjugated to an amine group (-NH2) was found to be optimum for coupling with mAbs. The optimal mAb concentrations for coupling to the fMA along with mycotoxin purification capacities of the fMA-mAb conjugates (fMA-AFB1 and fMA-ZEN) were determined. A comparison of mean recovery rates (from corn and product X feed) between the fMA-mAb conjugates and immunoaffinity columns (IAC-AFB1 and IAC-ZEN) showed that the rate for fMA-AFB1 (90~92% and 81~88%) was higher (p > 0.05) than that of IAC-AFB1 (81~84% and 72~78%) for AFB1 (5, 10, 15 ng/mL), and the rate for fMA-ZEN (99~100% and 92~94%) was significantly higher (p 30 min). This study suggests that the novel purification system we developed would be a useful tool for monitoring and regulating mycotoxin contamination in feed, and replace IAC methods.


Asunto(s)
Aflatoxina B1 , Anticuerpos Monoclonales , Magnetismo , Imanes , Micotoxinas , Nanopartículas , Zea mays , Zearalenona
19.
International Journal of Biomedical Engineering ; (6): 367-370, 2011.
Artículo en Chino | WPRIM | ID: wpr-417551

RESUMEN

Stimuli-sensitive drug delivery system (SSDDS) is an novel drug delivery carrier.It is sensitive to either the internal physiopathologic changes (pH,temperature) of the body or external stimulus signal (ultrasound,magnetic signal) and controls the release of the drugs that it carries according to the variation of physicochemical property which stimulated by the signals.SSDDS can be prepared from hydrogels,liposomes and magnetic nanoparticles.In contrast to non-stimuli-responsive drug delivery system,SSDDS has remarkable advantages including feedback regulation,stronger controllability and targeting therapy.This paper will review the advancement in stimuli-responsive drug delivery system in recent years.

20.
Journal of Pharmaceutical Analysis ; (6): 166-174, 2011.
Artículo en Chino | WPRIM | ID: wpr-472939

RESUMEN

Glypican-3 (GPC3) is reported as a great promising tumor marker for hepatocellular carcinoma (HCC) diagnosis.Highly sensitive and accurate analysis of serum GPC3 (sGPC3),in combination with or instead of traditional HCC marker alpha-fetoprotein (AFP),is essential for early diagnosis of HCC.Biomaterial-functionalized magnetic particles have been utilized as solid supports with good biological compatibility for sensitive immunoassay.Here,the magnetic nanoparticles (MnPs) and magnetic microparticles (MmPs) with carboxyl groups were further modified with streptavidin,and applied for the development of chemiluminescence enzyme immunoassay (CLEIA).After comparing between MnPs- and MmPs-based CLEIA,MnPs-based CLEIA was proved to be a better method with less assay time,greater sensitivity,better linearity and longer chemiluminescence platform.MnPs-based CLEIA was applied for detection of sGPC3 in normal liver,hepatoeirrhosis,secondary liver cancer and HCC serum samples.The results indicated that sGPC3 was effective in diagnosis of HCC with high performance.

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