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Introducción: El panorama demográfico en el mundo está cambiando. La población mayor de 60 años es el segmento que está creciendo más rápidamente y en el que las enfermedades del tejido óseo se presentan con más frecuencia, lo que aumenta la demanda de materiales y tecnologías apropiadas para restaurar estos tejidos. Objetivo: Analizar la información que se ha generado sobre el desarrollo de biomateriales compuestos para la reparación ósea, con énfasis en la identificación de las tecnologías emergentes basadas en el uso del campo electromagnético, sus aplicaciones y potencialidades. Métodos: Se consultaron trabajos científicos publicados en libros, revistas, patentes y tesis. El 80 por ciento de la documentación seleccionada pertenece al periodo 2010-2019. Análisis e integración de la información: Los métodos identificados fueron clasificados en cinco grupos: electrodeposición química, ya sea por electrólisis, electroforesis o síntesis electroforética in situ; electroporación; electrohilado; control magnético distal y bioestimulación electromagnética de células y tejidos, directamente o por la introducción de dispositivos que convierten la energía electromagnética en energía mecánica. Conclusiones: Estos métodos permiten la conformación de matrices celulares y acelulares compuestas y, además, dispositivos bioestimuladores con control de los parámetros de construcción y acción, de tal manera, que se logran procesos con mayor grado de reproducibilidad y a la medida de los requerimientos específicos para cada paciente(AU)
Introduction: The global demographic panorama is changing. The population aged over 60 years is the fastest growing segment, as well as the one where bone tissue diseases are most common, increasing the demand of appropriate materials and technologies to restore those tissues. Objective: To analyze the information so far generated about the development of composite biomaterials for bone repair, with an emphasis on the identification of emerging technologies based on the use of the electromagnetic field, its applications and potential. Methods: An analysis was performed of scientific papers published in books, journals, patents and theses. Of the documentation selected, 80 percent was from the period 2010-2019. Data analysis and integration: The methods identified were classified into five groups: chemical electrodeposition, be it by in situ electrophoretic synthesis, electrolysis or electrophoresis; electroporation; electrospinning; distal magnetic control and electromagnetic biostimulation of cells and tissues, either directly or incorporating devices which convert electromagnetic energy into mechanical energy. Conclusions: These methods permit the conformation of composite cellular and acellular matrices as well as biostimulator devices controlling construction and action parameters in such a way that the processes obtained display greater reproducibility and are more in keeping with the specific requirements of each patient(AU)
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Humanos , Materiais Biocompatíveis/análise , Estimulação Elétrica/métodos , Campos EletromagnéticosRESUMO
Objective To establish a nanometer magnetic particle chemiluminescence methodfor the detection of specific IgE antibodies to Tyrophagus putrefaciens allergen.Methods According to the routine operation steps of chemiluminescence, chemiluminescence reaction system and suitable immune reaction conditions for detection of specific IgE of Tyrophagus putrescentiae allergen are established. Considering the performance of the chemiluminescence method established in this paper, the American Somerfly Phadia method wasused as the gold standard to evaluate the test performance of the established chemiluminescence method. Results In thechemiluminescence reaction system, Luminol concentration in luminescent substrate A solution is 0.4 mg/ml, Urea hydrogen peroxidein luminescent substrate B solutionis 0.2 mg/ml.The sensitivity of this luminescent reaction system to horseradish peroxidase (HRP) is very high, the minimum detectable HRP is 0.01 ng/ml. In the immune response, the room temperature light-shielding reaction was detected for 5 min after the addition of substrates A and B, and the detection values were effective within 5-30 min. 37 ℃ is optimum luminescence reaction temperature. Choose the range of 0.35-100 IU/ml as the standard curve. According to the results of 120 clinical trials, using Phadia (immunofluorescence method) as the gold standard, the chemiluminescence method established in this study has significant significance for the detection of Tyrophagus putrescentiae allergen.Conclusion A nanometer magnetic particle chemiluminescence method was successfully established for the detection of specific IgE antibodies to Tyrophagus putrescentiae allergen.
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Objective@#To establish a nanometer magnetic particle chemiluminescence methodfor the detection of specific IgE antibodies to Tyrophagus putrefaciens allergen.@*Methods@#According to the routine operation steps of chemiluminescence, chemiluminescence reaction system and suitable immune reaction conditions for detection of specific IgE of Tyrophagus putrescentiae allergen are established. Considering the performance of the chemiluminescence method established in this paper, the American Somerfly Phadia method wasused as the gold standard to evaluate the test performance of the established chemiluminescence method.@*Results@#In thechemiluminescence reaction system, Luminol concentration in luminescent substrate A solution is 0.4 mg/ml, Urea hydrogen peroxidein luminescent substrate B solutionis 0.2 mg/ml.The sensitivity of this luminescent reaction system to horseradish peroxidase (HRP) is very high, the minimum detectable HRP is 0.01 ng/ml.In the immune response, the room temperature light-shielding reaction was detected for 5 min after the addition of substrates A and B, and the detection values were effective within 5-30 min. 37 ℃ is optimum luminescence reaction temperature. Choose the range of 0.35-100 IU/ml as the standard curve. According to the results of 120 clinical trials, using Phadia (immunofluorescence method) as the gold standard, the chemiluminescence method established in this study has significant significance for the detection of Tyrophagus putrescentiae allergen.@*Conclusion@#A nanometer magnetic particle chemiluminescence method was successfully established for the detection of specific IgE antibodies to Tyrophagus putrescentiae allergen.
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To explore the immobilization of target proteins for screening libraries of ligand mixtures, magnetic submicron particles (MSP) functionalized with Ni²⁺-NTA and carboxyl were compared for the immobilization of Mycobacterium tuberculosis dihydrofolate reductase (MtDHFR). MtDHFR fused with 6×His was expressed, purified and characterized for kinetics. MtDHFR was immobilized on Ni²⁺-NTA-functionalized MSP directly and carboxyl-functionalized MSP upon activation. The immobilization capacity, residual activity, thermostability and affinities for putative inhibitors were characterized. MtDHFR immobilized on Ni²⁺-NTA-functionalized MSP retained about 32% activity of the free one with the immobilization capacity of (93±12) mg/g of MSP (n=3). Ni²⁺ and EDTA synergistically inhibited MtDHFR activity, while Fe³⁺ had no obvious interference. MtDHFR immobilized on carboxyl-functionalized MSP retained (87±4)% activity of the free one with the immobilization capacity of (8.6±0.6) mg/g MSP (n=3). In 100 mmol/L HEPES (pH 7.0) containing 50 mmol/L KCl, there was no significant loss of the activities of the free and immobilized MtDHFR after storage at 0 °C for 16 h, but nearly 60% and 35% loss of their activities after storage at 25 °C for 16 h, respectively. The inhibition effects of methotrexate on the immobilized and free MtDHFR were consistent (P>0.05). The immobilization of MtDHFR on carboxyl-functionalized MSP was thus favorable for higher retained activity and better thermostability, with promise for rapid screening of its ligand mixtures.
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Estabilidade Enzimática , Enzimas Imobilizadas , Concentração de Íons de Hidrogênio , Cinética , Ligantes , Nanopartículas de Magnetita , Mycobacterium tuberculosis , Temperatura , Tetra-Hidrofolato DesidrogenaseRESUMO
Objective To investigate the antitumor therapeutic effect of combined therapy of magnetic induction heating by nano-magnetic particles, herpes simplex virus thymidine kinase gene(HSV-tk suicide gene) and internal radiation in mice bearing MCF-7 breast carcinoma. Methods The transfection reagents, plasmids heat shock protein-HSV-tk (pHSP-HSV-tk), ferroso-ferric oxide nano-magnetic fluid flow and 188Re-ganciclovir-bovine serum albumin-nanopaticles (GCV-BSA-NP) were prepared. The heating experiments in vivo were carried out using ferroso-ferric oxide nano-magnetic fluid flow. Sixty mice tumor models bearing MCF-7 breast carcinoma were established and randomly divided into six groups. Group A was the control group, B was gene transfection therapy group, C was hyperthermia group, D was gene transfection therapy combined with radionuclide brachytherapy group, E was gene therapy combined with hyperthermia group, and F was gene therapy, hyperthermia combined with radionuclide brachytherapy group. The tumor growth, tumor mass and histopathological changes were evaluated. The expression of HSV-tk in the groups of B, D, E and F was detected by RT-PCR. Poisson distribution and one-way analysis of variance (ANOVA) were used for statistical analysis by SPSS 10.0 software. Results In the animal heating experiments, the temperature of tumor increased up to 39.6 ℃, 43.2 ℃, and 48.1 ℃ quickly with different injected doses (2, 4 and 6 mg respectively) of nano-magnetic particles and maintained for 40 min. The temperature of tumor tissue reduced to 36.8 ℃, 37.5 ℃ and 37.8 ℃ in 10 min when alternating magnetic field (AMF) stopped. The tumor mass in Groups C ((452.50 ±30.29) mg), D ((240.98 ±35.32)mg), E((231.87 ±27.41) mg) and F ((141.55 ±23.78) mg) were much lower than that in Group A ((719.12±22.65) mg) (F=800.07, P＜0. 01), with the most significant treatment effect in Group F.The tumor mass in Group B((684.05 ±24.02) mg) was higher than that in Group D (t =32. 805, P ＜0. 05). Semi-quantitative RT-PCR analysis showed that the expression of HSV-tk in Groups B and D (0.33 ±0. 13 and 0. 46 ±0.12) was significantly different from that in Groups E and F (0.66 ±0.13 and 0.74 ±0. 11)(F = 21. 573, P ＜ 0.05). Conclusion Combined use of hyperthermia, gene therapy and radionuclide brachytherapy could effectively depress the growth of MCF-7 breast carcinoma, thus possessing treatment potential for this tumor.
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OBJECTIVE To establishan immuno-PCR assay with the carriers of gold-magnetic particles for detection of HIV-1 p24. METHODS The feasibility of using gold-magnetic particles as the carriers was verified. The gold-magnetic particles were coated with mouse anti-p24 monoclonal antibody as the capture antibody. The reporter DNA was initially generated by PCR amplification using a biotinylated primer, and was bound through streptavidin to biotinylated polyclonal antibody as the detection antibody. HIV-1 p24 sandwiched by two antibodies was detected by amplifying the reporter DNA using PCR. RESULTS The efficiency of gold-magnetic particles coated with mouse anti-p24 monoclonal antibody could reach up to 95%. Furthermore, the amount of antibodies immobilization was consistent among different batches of gold-magnetic particles and there was nearly without nonspecific adsorption. The detection limit of immuno-PCR assay was 0.1 ng/L, an approximately 1.5?104-fold higher compared with an enzyme-linked immunosorbent assay. The linear range of p24 concentration was 0.1-100 ng/L. CONCLUSIONS Gold-magnetic particle is one of the ideal immuno-PCR reaction carriers. The immuno-PCR for detection of HIV-1 p24 reported in this article is indicated to be a promising detection method.