Silver Nanoparticles and PDMS Hybrid Nanostructure for Medical Applications

For many years, people have known about silver’s antibacterial qualities. Silver nanoparticles are widely used in consumer products, biomedical equipment, textile products and in other applications. Having a larger surface area to coat or spread over another surface, offers a greater contact area, therefore, increases antimicrobial properties. Also, these nanoparticles can be incorporated into polydimethylsiloxane (PDMS) implants as immobilized or occluded particles to improve their performance in the body. PDMS is commonly used for biomedical applications, including components for microfluidics, catheters, implants, valves, punctual plugs, orthopedics and micro gaskets. It can be manufactured easily in different forms such as fibers, fabrics, films, blocks and porous surfaces. The use of silver nanoparticles for their antimicrobial qualities improves PDMS biocompatibility, because it inhibits microbial growth, thereby making it more attractive for biomedical applications. The presence of metal nanoparticles also helps to reduce the hydrophobic nature of PDMS. This property of PDMS does not encourage cell adhesion, which is a very critical requirement for medical implants. Silver nanoparticles improve the silicone’s wettability. The exceptional properties of silver nanoparticles combined with the PDMS have made this hybrid nanostructure applicable to different medical uses

Current strategies in cationic liposomal vaccine development for anti-cancer therapy

Nanomedicine is currently at the forefront of technology. Nanovaccines are a relevant development derived from this field and comprise nanoparticles ranging from 50-250 nm to deliver antigens and other immunomodulatory agents. Their formulation can include liposomes, which are widely known as safe and allow their engineering to be cationic, conferring a superior immunostimulatory effect. This promising strategy for vaccine delivery has gained interest in cancer as it provides higher targeting efficiency, increased antigen stability, prolonged circulation time, and enhanced uptake by antigen-presenting cells, mainly dendritic cells. Therefore, this minireview discusses recent research on cationic liposome-based vaccine delivery systems for anti-cancer therapy. Pubmed, Science Direct, and Google Scholar were screened for original and review papers published in the last ten years. The antigen association with the cationic nanoparticles either by electrostatic interactions or complementary coiled coil peptide pair strategy were found as the most promising strategies. The work also highlights the potential of this therapeutic platform for enhancing the T-cell immune response against cancer through mRNA-containing formulations for different routes of administration, providing a detailed physicochemical characterization of the reported nanosystems

Ampicillin-Loaded Chitosan Nanoparticles for In Vitro Antimicrobial Screening on Escherichia coli

Purpose: To develop ampicillin-loaded chitosan nanoparticles by modified ionic gelation method for evaluating their antimicrobial activity onto Escherichia coli

Influencia de las nanopartículas de sílice en polímeros termoplásticos

En este trabajo se prepararon sílices con distinto grado de hidrofilicidad para reducir el grado de interacción con el poliuretano y analizar la incidencia en las propiedades de los materiales compuestos obtenidos. Se incorporó una sílice pirogénica hidrófila a adhesivos de poliuretano con distinta relación NCO/OH donde el grado de separación de fases se vio favorecido en todos los poliuretanos, indicando una posible interacción de los grupos silanol de la sílice mediante enlaces de hidrógeno con el polímero. Por lo tanto, debería existir una variación de propiedades en los poliuretanos como respuesta a la presencia de la sílice dispersada.In this work we have prepared silicas with different hydrophilicity to reduce the degree of interaction with the polyurethane and analyze the effect on the properties of the composites obtained. A hydrophilic pyrogenic silica was incorporated in different polyurethane adhesives with different relation NCO/OH where the degree of phase separation is enhanced at all polyurethanes, indicating a potential interaction of the silanol groups of the silica by hydrogen bonding with the polymer. Therefore, there should be a variation in properties as polyurethanes response to the presence of the dispersed silica

Modelando la dinámica de un cantiléver de Microscopía de Fuerza Atómica AFM

AbstractCurrently some research involves computing, as well as experiment. On the other hand, computersimulation can provide valuable approaches to scientific problems. The atomic force microscopy(AFM) is one of the scanning probe microscopy techniques, which locally scans interatomic forcesbetween a sample and a probe. The oscillatory motion of the cantilever can be simulated mathematicallyusing a forced damped harmonic oscillator model. The fact that it is possible to mathematicallyapproach the behaviour of the cantilever-sample system, allows them to be programmed and computedto predict the physical behavior at a theoretical level.Keywords: Simulation, dynamics, cantilever, AFM.  Parte de la investigación científica actual involucra el empleo de diversas herramientas computacionales,tanto teóricas como de experimentación. La simulación computacional puede brindar acercamientosvaliosos a la resolución de problemas científicos. La microscopía de fuerza atómica (AFM) constituyeuna de las técnicas de microscopía de sonda local; busca escanear las fuerzas interatómicas quepueden establecerse entre una muestra y una sonda. El movimiento oscilatorio del cantiléver se puedemodelar matemáticamente utilizando los primeros armónicos de la ecuación de un oscilador armónicoforzado con amortiguamiento. El hecho de que sea posible modelar matemáticamente permite queambos comportamientos puedan ser programados y computados para la predicción del comportamientofísico a nivel teórico. 

Síntesis y caracterización de nanosílices funcionalizadas injertadas con 3-aminopropil trietoxisilano para ser utilizadas en adhesivos de poliuretano

En este trabajo se presentan los resultados obtenidos al modificar superficialmente una sílice pirogénica hidrófila comercial, con una superficie específica de 200 m2 /g, a la que se le injertó 3-aminopropiltrietoxisilano. La nanosílice modificada se añadió a adhesivos de poliuretano termoplástico en metiletilcetona. El material obtenido se caracterizó mediante sus propiedades mecánicas, térmicas, reológicas y adhesivas. Los resultados obtenidos se compararon con los de adhesivos de poliuretano sin sílice y con sílice sin modificar, preparados bajo las mismas condiciones experimentales.Fil: Vega Baudrit, José. Universidad Nacional. Escuela de Química. Laboratorio de Polímeros; Costa RicaFil: Sibaja Ballestero, María. Universidad Nacional. Escuela de Química. Laboratorio de Polímeros; Costa RicaFil: Martín Martinez, José Miguel. Universidad de Alicante. Departamento de Química Inorgánica. Laboratorio de Adhesión y Adhesivos; EspañaFil: Vazquez, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentin

Electrospun nanofibers: A nanotechnological approach for drug delivery and dissolution optimization in poorly water-soluble drugs

Electrospinning is a novel and sophisticated technique for the production of nanofibers with high surface area, extreme porous structure, small pore size, and surface morphologies that make them suitable for biomedical and bioengineering applications, which can provide solutions to current drug delivery issues of poorly water-soluble drugs. Electrospun nanofibers can be obtained through different methods asides from the conventional one, such as coaxial, multi-jet, side by side, emulsion, and melt electrospinning. In general, the application of an electric potential to a polymer solution causes a charged liquid jet that moves downfield to an oppositely charged collector, where the nanofibers are deposited. Plenty of polymers that differ in their origin, degradation character and water affinity are used during the process. Physicochemical properties of the drug, polymer(s), and solvent systems need to be addressed to guarantee successful manufacturing. Therefore, this review summarizes the recent progress in electrospun nanofibers for their use as a nanotechnological tool for dissolution optimization and drug delivery systems for poorly water-soluble drugs.</p

Effect of Silver Nanoparticles on White-Rot Wood Decay and Some Physical Properties of Three Tropical Wood Species

Wood is one of the most widely used materials and is used in many applications. However, decay resistance of wood is limited in tropical conditions. Nanotechnology applications have potential for improving materials. In this study, a solution with a concentration of 50 ppm silver nanoparticles was incorporated by pressure into three commercial species (Acacia mangium, Cedrela odorata, and Vochysia guatemalensis) of Costa Rica. The white-rot fungus (Trametes versicolor) was tested, and some physical properties were also measured. According to the results, synthetized silver nanoparticles (10-25 nm) presented little agglomeration and were adequately distributed. The retention achieved was 25-102 silver mg/kg-1 of wood, varying among species and with presence of sapwood and heartwood. Mass loss was less than 5% in wood treated with silver nanoparticles; thus, the wood was classified as highly resistant or class A. Meanwhile, untreated wood presented losses greater than 20% with white-rot fungi. Also, water absorption capacity decreased for wood treated with silver nanoparticles in the three species tested, and dimensional stability increased for Cedrela odorata and Vochysia guatemalensis treated with silver nanoparticles

PROPUESTA DE INCORPORACIÓN DE LA NANOTECNOLOGÍA EN LA EDUCACIÓN FORMAL MEDIA EN COSTA RICA

El programa actual de educación media y diversificada en Costa Rica se está modificando a un sistema donde se desarrolle la observación, experimentación, investigación e indagación; tratando de mejorar y actualizar sus contenidos y métodos.Se propone un nuevo enfoque del currículum escolar basado en la revisión de las ciencias básicas en la escuela media; y la física, la biología y la química en la educación diversificada. Donde se podrían incorporar experimentos simples de nanotecnología o nanobiotecnología y una breve guía de investigación para la feria científica.La propuesta presentada es para promover la nanotecnología como herramienta para fomentar el interés científico y las vocaciones científicas.Costa Rica’s current middle school curriculum is being migrated or is being modified to a system where students develop skills in observation, experimentation, research and inquiry, aiming to improve and update contents and methods.We propose here a new approach to the curriculum based on the review of basic sciences in middle school and physics, biology and chemistry in diversified education. Where, simple nanotechnology or nanobiotechnology experiments and a short research guide for the scientific fair could be incorporated.The proposal is to use nanotechnology as an educational tool to foster scientific interest and scientific vocations