Nanofiber scaffolds of polyvinyl alcohol, silk fibroin from Bombyx mori cocoons, and silver nanoparticles were developed as a substrate for MG-63 growth. The fiber morphology, mechanical properties, thermal degradation, chemical composition, and water contact angle were investigated. In vitro tests were performed by the cell viability MTS test of MG-63 cells on electrospun PVA scaffolds, mineralization was analyzed by alizarin red, and the alkaline phosphatase (ALP) assay was evaluated. At higher PVA concentrations, Young's modulus (E) increased. The addition of fibroin and silver nanoparticles improved the thermal stability of PVA scaffolds. FTIR spectra indicated characteristic absorption peaks related to the chemical structures of PVA, fibroin, and Ag-NPs, demonstrating good interactions between them. The contact angle of the PVA scaffolds decreased with the incorporation of fibroin and showed hydrophilic characteristics. In all concentrations, MG-63 cells on PVA/fibroin/Ag-NPs scaffolds had higher cell viability than PVA pristine. On day ten of culture, PVA18/SF/Ag-NPs showed the highest mineralization, observed by the alizarin red test. PVA10/SF/Ag-NPs presented the highest alkaline phosphatase activity after an incubation time of 37 h. The achievements indicate the potential of the nanofibers of PVA18/SF/Ag-NPs as a possible substitute for bone tissue engineering (BTE).

In wet electrospinning, a natural or synthetic polymer solution is deposited on a non-solvent liquid coagulant used as collector. This technique can create 3D nanofiber scaffolds with better properties (e.g., porosity and high surface area) than those of traditional 2D scaffolds produced by standard electrospinning. Thanks to these characteristics, wet electrospinning can be employed in a wide range of tissue engineering and industrial applications. This review aims to broaden the panorama of this technique, its possible fields of action, and its range of common materials. Moreover, we also discuss its future trends. In this study, we review papers on this method published between 2017 and 2021 to establish the state of the art of wet electrospinning and its most important applications in cardiac, cartilage, hepatic, wound dressing, skin, neural, bone, and skeletal muscle tissue engineering. Additionally, we examine its industrial applications in water purification, air filters, energy, biomedical sensors, and textiles. The main results of this review indicate that 3D scaffolds for tissue engineering applications are biocompatible; mimic the extracellular matrix (ECM); allow stem cell viability and differentiation; and have high porosity, which provides greater cell infiltration compared to 2D scaffolds. Finally, we found that, in industrial applications of wet electrospinning: (1) additives improve the performance of pure polymers; (2) the concentration of the solution influences porosity and fiber packing; (3) flow rate, voltage, and distance modify fiber morphology; (4) the surface tension of the non-solvent coagulant on which the fibers are deposited has an effect on their porosity, compaction, and mechanical properties; and (5) deposition time defines scaffold thickness.

In this work, electrospinning was used for the preparation of composite nanofibrous scaffold, of polyvinyl alcohol (PVA), silk fibroin (SF) extract of Bombyx mori cocoons and silver nanoparticles (Ag NPs), as a substrate for bone tissue engineering. The PVA pristine was prepared at a concentration of 10% wt. The composite nanofibers scaffolds of PVA was prepared with silk fibroin and silver nanoparticles, in relation of PVA: SF (90:10) (v/v) respectively. The formation and presence of AgNPs was confirmed by ultraviolet-visible spectroscopy (Uv-vis). The diameter distribution of the nanofibers was narrow by SEM using Image J software. The chemical composition was determined by FTIR spectra. The wettability was determined using water contact angle. The results showed the average nanofiber diameter of PVA10 pristine was 108.18 nm and to PVA10/SF/Ag NPs was 106.62 nm, no significant changes were noted in the mean diameter, but there were changes in its morphology. The average nanofiber diameter increase with the concentration of PVA at PVA15/SF/Ag NPs was 189.12 nm to PVA18/SF/Ag NPs was 224,23 nm. FTIR spectra indicated characteristic absorption peaks related to the chemical structure of PVA, fibroin and Ag NPs, it demonstrated good interactions between them, caused by strong intermolecular hydrogen bonds. The contact angle of the scaffolds PVA 10%wt decrease with the incorporation of fibroin and show hydrophilic characteristics. The achievements indicate the potential of the nanofibers of PVA15/SF/Ag NPs as a possible substitute for bone tissue engineering.Clinical Relevance-This establishes a possible substrate of PVA/SF/Ag NPs that exhibit desired properties such as porosity and high surface area to volume ratio for bone tissue engineering.

RESUMENLa búsqueda de alternativas para tratamientos al cáncer que puedan ser de bajo costo, menos invasivos y con menores efectos secundarios, sigue siendo un tema de continuo interés. El estudio de un sistema combinado de campos eléctricos de bajo voltaje con nanomateriales, estos últimos actuando como nanovectores, en el tratamiento de cáncer ha mostrado resultados prometedores. En este trabajo se presenta el diseño, simulación y construcción de un equipo estimulador eléctrico tipo capacitivo de bajo voltaje para estimular células tipo fibrobastos normales y tipo melanoma combinadas con nanopartículas de oro. El equipo permite variación en voltaje, frecuencia, intensidad de corriente, forma de onda y ciclo de dureza. El diseño fue realizado en la plataforma Arduino Due, llevado a Eagle para el desarrollo PCB y con visualización en pantalla LCD. El generador construido es finalmente conectado a un par de placas paralelas encargadas del campo eléctrico que será inducido. De las variables entregadas por el equipo se encontraron exactitudes inferiores al 1,5% lo que garantiza el cumplimiento técnico del equipo en las variables necesarias.

En el presente trabajo se estudió los efectos de los parámetros de electrohilado sobre las propiedades morfológicas y mecánicas de membranas de policaprolactona (PCL) con óxido de grafeno reducido térmicamente (TrGO). TrGO se obtuvo a través del método de Hummers modificado. Para preparar las soluciones se usaron PCL, TrGO y acetona. La relación polímero - acetona fue del 10% p/v y la relación de polímero - TrGO fue del 1% p/p. Las membranas se prepararon bajo los siguientes parámetros: flujo (3 ml/hl y 6 ml / h), voltaje (10 kV y 15kV) y distancia del colector a la punta (10 cm y 15 cm). La morfología de las muestras se observó mediante un microscopio electrónico de barrido y un microscopio óptico, y las pruebas de resistencia se realizaron con una Máquina Universal. La presencia de más cuentas fue evidente en las muestras con un flujo de 3 ml/h, esto afectó las propiedades mecánicas de las membranas. Los diámetros más grandes se obtuvieron para muestras con un caudal de 6 ml / h. Se observó un efecto negativo sobre el esfuerzo final para las membranas obtenidas con una distancia de 15 cm. Fibras secas antes de llegar al colector pueden ser la causa.

The incorporation of nanoparticles inside polymeric matrices has led to the development of multifunctional composites necessary to repair human tissues. The addition of nanoparticles may improve the properties of the composite materials such as surface area, mechanical properties, flexibility, hydrophilicity, electrical conductivity, etc. These properties can help in cellular growth, proliferation and/or differentiation. In this work, scaffolds of polycaprolactone (PCL) and reduced graphite oxide (rGO) were built by electrospinning technique. The ratios of rGO/PCL employed were 0.25, 0.5, 0.75 and 1 wt%. Two different voltage setup (10 and 15 kV) and distance of 10 cm were used for electrospinning. Thermal, mechanical, morphological, electrical, porosity and absorption water tests were made to the scaffolds. Samples electrospun at 10 kV with rGO showed improvement in mechanical properties with an increase of 190% of Young's Modulus in comparison with sample without rGO. Furthermore, samples electrospun at 15 kV showed an important deterioration with the addition of rGO but had an increase in the electrical conductivity and porosity. Overall, the addition of 0.75 and 1 wt% of rGO led to a detriment on properties due to formation of aggregates. The voltage on the electrospinning process plays a very important role in the final properties of the nanocomposites scaffolds of PCL-rGO.

In the present work, the effects of electrospinning parameters on the morphological and mechanical properties of polycaprolactone (PCL) membranes with thermally reduced graphene oxide (TrGO) were studied. TrGO was obtained through the modified Hummers method. PCL, TrGO and acetone were used to prepare the solutions. The polymer-acetone ratio was 10% w / v and the polymer-TrGO ratio was 1% w / w. The membranes were prepared under the following parameters: flow (3 ml / hl and 6 ml / h), voltage (10 kV and 15 kV) and distance from the collector to the tip (10 cm and 15 cm). The morphology of the samples was observed by means of a scanning electron microscope and an optical microscope, and the resistance tests were carried out with a Universal Machine. The presence of more beads was evident in the samples with a flow rate of 3 ml / h, this affected the mechanical properties of the membranes. The largest diameters were obtained for samples with a flow rate of 6 ml / h. A negative effect on the final stress was observed for the membranes obtained with a distance of 15 cm. Dry fibers before reaching the collector can be the cause.

A polymer electrolyte system based on polycaprolactone and silver nitrate with different compositions has been prepared by slow solvent evaporation. The results demonstrate that a decrease in the crystallinity of the sample was evidenced when the salt content was increased. The impedance spectroscopy tests were performed wetting the samples in order to simulate bone water content. The highest conductivity (9.02x10(3) S/m) was found for PCL + 20% AgNO3 with water. The activation energy of this sample was calculated from the Arrhenius plot and it was 0.27 eV while the relative crystallinity obtained from thermal analysis was 74.9%. Nevertheless, for the purpose of this work and considering the conductivity of cortical bone between 2 x 10(3) S/ m and 7 x 10(3) S/ m, PCL + 10% AgNO3 and PCL + 14% AgNO3 may also be used. (C) 2017 Elsevier B. V. All rights reserved.

Various modeling and simulation studies about cellular systems reactions and human exposure to external electric fields, have established exposure thresholds, therapeutic application ranges, and different levels of experimental variables in order to use in different pathologies and characterization of physio-electric mechanisms. In this work, we developed a 3D computational model that consists of an electric field source and cell content deposited in a Falcom plate. The model considered the geometries, properties, meshing, simulation conditions, and type of results analysis. The development was performed in the ANSYS® software and it allowed estimate the behavior of the induced current density in cell cultures from various stimulation conditions. The developed model and the results are supportive of the estimation and prediction of the electrical signal induced in cells with which to associate a biological response.

Cada vez es más común el uso de campos magnéticos a nivel celular para evaluar su interacción con los tejidos biológicos. La estimulación se hace generalmente con bobinas Helmholtz que generan un campo magnético uniforme en el centro del sistema. Sin embargo, evaluar el comportamiento celular con diferentes características del campo magnético puede ser un proceso largo y costoso. Para esto, se pueden utilizar modelos computacionales para estimar previamente el comportamiento celular debido a la variedad de características de campo antes de la estimulación in vitro en un laboratorio. En este artículo se presenta una metodología para el desarrollo de tres modelos computacionales de sistemas de generación de campos magnéticos homogéneos para su posible aplicación en la estimulación de células. Los modelos fueron desarrollados en el entorno de ANSYS Workbench y se evaluó el comportamiento de la densidad de campo magnético en diferentes configuraciones. Los resultados fueron validados con los cálculos teóricos a partir de la ley de Biot-Savart. Los modelos validados serán acoplados al ambiente Ansys APDL con el fin de evaluar la respuesta del sistema en estado armónico.

This articles presents a literature review on the main mechanical and physicochemical properties of biocompatible materials used in maxillary bone regeneration is presented. The materials are classified according to their origin in autologous bone, allograft, xenograft, alloplastic and compound materials. The materials were cataloged according to mechanical strength properties, charging time or periods of physiological adaptation, reabsorption, and adhesion. The study allowed identifying relevant factors to ensuring better properties in maxillary bone regeneration.

It is increasingly common to use magnetic fields at the cellular level to assess their interaction with biological tissues. The stimulation is usually done with Helmholtz coils which generate a uniform magnetic field in the center of the system. However, assessing cellular behavior with different magnetic field characteristics can be a long and expensive process. For this, it can be used computational models to previously estimate the cellular behavior due to variety of field characteristics prior to in-vitro stimulation in a laboratory. In this paper, we present a methodology for the development of three computational models of homogeneous magnetic field generation systems for possible application in cell stimulation. The models were developed in the Ansys Workbench environment and it was evaluated the magnetic flux density behavior at different configurations. The results were validated with theoretical calculations from the Biot-Savart law. Validated models will be coupled to Ansys APDL environment in order to assess the harmonic response of the system.

Diversos estudios de modelamiento y simulación de reacciones de sistemas celulares y exposición humana ante campos eléctricos externos, han permitido establecer umbrales de exposición, rangos de aplicación terapéutica y niveles experimentales de diferentes variables eléctricas con miras de uso a diferentes patologías y caracterización de mecanismos fisioeléctricos. En este trabajo se desarrolló un modelo computacional 3D conformado por una fuente de campo eléctrico y un contenido celular depositado en una caja tipo Falcom. El modelo consideró las geometrías, propiedades, mallado, condiciones de simulación y tipo de análisis de resultados. El desarrollo fue realizado en la herramienta computacional ANSYS® y con este se logró estimar el comportamiento de la densidad de corriente inducidas en los cultivos celulares a partir de diversas condiciones de estimulación. El modelo creado y los resultados encontrados son un apoyo para la estimación y predicción de la señal eléctrica inducida en los cultivos con la que asociar una respuesta biológica encontrada.

Starting from the fact that the electromagnetic fields of high frequencies like the rays X, produces alteration at level genético[1], the doubt was born on if the magnetic fields generated by the electric system of energy (60 Hz) they could cause similar effects that were harmful for the human health. In this article a description of the main methods is made used for the study of the biological effects of the magnetic fields, the results obtained in some studies and the position of different institutions and organizations. Equally the importance is presented of making on the topic a communication social clear.

La electricidad en los tejidos vivos fue ampliamente estudiada alrededor del siglo XIX. Los estudios fueron suspendidos durante muchos años y retomados en las últimas décadas. Las nuevas investigaciones en bioelectricidad están creando alternativas en el área de la salud, una de éstas es la respuesta electrodermal, asociada con reparación de heridas, estimulación celular, diagnóstico de psicopatologías, entre otras. Este artículo presenta algunos de los primeros hallazgos y modelos desarrollados alrededor de la actividad electrodermal (AED). Varios documentos teóricos, clínicos y de revisión fueron estudiados y clasificados para mostrar la amplitud y variedad de hallazgos sobre el tema presentado. La actividad electrodérmica es sólo una de las múltiples aplicaciones con abundante evidencia en diagnósticos y tratamientos a partir de señales bioeléctricas. Las respuestas eléctricas de los tejidos requieren más investigación experimental, teórica y clínica en muchas de las áreas que envuelven el comportamiento del organismo, para así conocer, proponer y crear nuevas alternativas de tratamiento a las diversas patologías.

En este trabajo fueron medidas la conductividad y permitividad eléctrica en muestras de la diáfisis de fémur de bovino; las muestras fueron llevadas a un ambiente computacional para calcular, a priori, señales eléctricas inducidas de interés experimental. De las muestras fueron construidos modelos computacionales 3D y asignadas propiedades eléctricas del estudio PE- y reportadas en la literatura PL-. La fuente generadora fue ubicada para campo magnético transversal y longitudinal a las muestras. Las señales eléctricas estudiadas fueron campo magnético, densidad de corriente y potencial eléctrico. Las propiedades eléctricas medidas estuvieron dentro del rango esperado, la densidad de corriente y el campo eléctrico inducidos fueron afectados por la propiedad asignada, la frecuencia, el tipo de tejido (medular o cortical) y la dirección del campo magnético inducido. Los mayores valores fueron obtenidos para estimulación a 120 Hz, dirección de campo magnético transversal y PLIn this paper electric permittivity and conductivity were measured in bovine femur diaphysis; samples were have on a computer environment to calculate a priori, induced electric signals of experimental interest. From samples three-dimensional computer models and reported in literature PL -. Generating source was located for a longitudinal and transversal magnetic field to samples. Study electric signals included magnetic field, current density, and electric potential. Electric properties measured were within expected rank, curent density and induced electric field were affected by assigned property, frequency, type of tissue (medullary or cortical), and direction of induced magnetic field. Higher values were obtained for stimulation to 120 Hz, direction of transversal magnetic field, and PL