ABSTRACT
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)
Subject(s)
Humans , Biocompatible Materials/analysis , Electric Stimulation/methods , Electromagnetic FieldsABSTRACT
BACKGROUND: Electrofabrication has broadened the structure, performance, and applications of biomedical materials. Through selecting appropriate materials and optimizing structures, tissue engineering scaffolds that conform to human physiological environment can be constructed, which is of considerable significance to promote the development of tissue engineering and regenerative medicine. OBJECTIVE: To review the research progress of electrofabrication technology in tissue engineering. METHODS: Web of Science Core Collection and MEDLINE databases were searched for relevant articles with the search terms “tissue engineering scaffold, electrodeposition, electrofabrication, electrogelation, bioprinting, biomedical materials, biopolymers” in English. After screening articles based on inclusion and exclusion criteria, articles with higher relevance were retained for review. RESULTS AND CONCLUSION: Electrofabrication can apply electrical signals to regulate material pores or layered structures through precise spatial, temporal and quantitative control, can quickly and controllably construct functional tissue engineering scaffold materials with complicated microstructures, but without the introduction of organic solvents or other biotoxic substances during the processing. Although there have been many research results on the electrofabrication of biological materials, there are few studies on how the electrofabrication parameters affect the material structure and deposition dynamics, and further theoretical and modeling work is needed to understand the mechanism involved in electrofabrication.
ABSTRACT
Based on microfabrication technology and electrochemical modification method, a micro electrochemical sensor for nitrate ( NO-3 ) determination was developed. A micro sensor chip with working electrode and counter electrode was used as the signal convertor of the sensor. The area of the micro working_electrode was only 1 mm2 . As an electrocatalysis sensitive material, copper was electrodeposited onto the working electrode by square_wave pulse current electrodeposition method. The morphologies and components of freshly deposited materials were examined by scanning electron microscopy ( SEM ) and X_ray diffraction ( XRD) to explore key factors that affected the electrocatalytic ability of the deposited copper layer for reducing nitrate ions. The experimental results revealed that under the optimal conditions, the deposited copper layer was macroporous and had a larger effective surface area that could serve as a more effective electrocatalyst in facilitating nitrate reduction. Electrochemical response of the macroporous copper layer was characterized by linear sweep voltammetry in acidic supporting electrolytes ( pH=2 ) . The electroanalytical results showed that the modified microsensor had marked sensitivity for standard nitrate samples within the concentration range from 12. 5 to 3000 μmol/L (in the range of 12. 5-200 μmol/L yielded straight line:y1=-0. 1422x-10. 326, R12=0. 9976, while in the range of 200-3000 μmol/L yielded straight line: y2=-0. 0984x-22. 144, R22=0. 9927) with a detection limit of 2 μmol/L (S/N=3). The developed electrochemical microsensor was also employed for nitrate determination in water samples collected from lakes and rivers near the city of Beijing. The results were in good agreement with the data given by qualified water quality detection institute, with the deviations from 3 . 9% to 15 . 4%.
ABSTRACT
La electrodeposición es un proceso químico por el cual se realiza una deposición galvánica de oro del 99% de pureza con el fin de obtener infraestructuras en prótesis metal-cerámicas. Las infraestructuras presentan, en promedio, un espesor de 0,2 mm y un desajuste marginal inferior la 20 µm, posibilitando la utilización de un mayor espesor de cerámica si la comparamos a técnicas convencionales. Esta técnica posibilita la disminución de la citotoxicidad, de las reacciones alérgicas y de la corrosión, determinando una mayor duración de las restauraciones. La coloración dorada del material permite al ceramista conseguir una estética más depurada, favoreciendo las tonalidades en la cerámica aplicada. Sin embargo, la necesidad de mano de obra calificada y de equipos modernos y de alto costo son factores que todavía hacen inviable la utilización de la electrodeposición de oro puro como práctica clínica habitual. El objetivo de este estudio es contribuir, a través de una revisión de la literatura, a la comparación en los siguientes factores: calidad del asentamiento marginal, durabilidad, biocompatibilidad, estética de las restauraciones cuyas estructuras hayan sido obtenidos por la técnica de electrodepoisición frente a restauraciones realizadas con técnicas metal-cerámicas convencionales y sistemas cerámicos
Electrodeposition is the galvanic deposition of 99% pure gold to obtain the framework for metal-ceramic prostheses. The framework is 0.2 mm thick, on average, with marginal maladjustment of less than 20 µm, enabling the use of greater ceramic thickness than that of conventional techniques. This new technique reduces cytotoxicity, allergic reactions and corrosion, resulting in longer restoration longevity. The golden coloration of the material allows the ceramist to develop a more evolved esthetic, favoring the tonality of the ceramic applied. However, the need for qualified labor and modern high-cost equipment are factors that hinder the use of electrodeposited pure gold in everyday clinical practice. The aim of this study is to perform a literature review to compare the quality of the marginal fit, longevity, biocompatibility, and esthetic of restorations whose copings were obtained by the electrodeposition technique using conventional metal-ceramics and ceramic systems
Subject(s)
Humans , Male , Female , Denture, Partial, Fixed , Gold Alloys , Electroplating , Metal Ceramic Alloys , Prostheses and Implants , Prosthesis Design , Tooth Crown , DentistryABSTRACT
To develop an insulated acupuncture needle with low resistance that causes little pain, insulated needles for acupuncture were prepared by electrodeposition of acrylic coatings such as acrylic/fluorine, acrylic/melamine, acrylic/urethane, and acrylic/epoxy resins. Wettability of these needles and resistance to insertion into muscle model (PVA Hydro-gel, Oil dispersed hydro-gel, and Pig muscle) and human tissue were investigated. Wettability of these coating films was estimated from contact angles of water droplets on the film coating. Resistance to insertion of these needles into Hydro-gel gradually increased with increases in their contact angles. Oil dispersed hydro-gel and Pig muscle showed inverse results. When these needles were inserted into human tissue, the acrylic/fluorine coated needle showed the least resistance and patients felt almost no pain.