PHYSICO-CHEMICAL PROPERTIES OF A NANOCOMPOSITE HYDROGEL COATING ON A TEXTILE CARRIER FOR THE WOUND TREATMENT

Нанотехнологии с использованием биополимеров находят широкое применение в биомедицинских приложениях. В данной работе разработаны нанокомпозитные гидрогели на основе природных (хитозан, карбоксиметилцеллюлоза) и синтетических (поливиниловый спирт) полимеров с наночастицами серебра для нанесения на текстильный носитель. В качестве сшивающих реагентов при создании гидрогелей использовали диальдегид карбоксиметилцеллюлозы и борную кислоту. Были определены физико-химические свойства (сорбционная способность при одностороннем контакте с модельной средой, степень набухания, паропроницаемость, капиллярность) гидрогелевых покрытий на текстильном носителе, и кинетика выхода лекарственных веществ (лидокаин, диоксидин), включенных в состав гидрогелей. Показано, что материалы с двухслойным покрытием характеризуются более высокими сорбционными свойствами по отношению к физиологическому раствору и более длительным выходом лекарственных средств, чем материалы с однослойным покрытием. Выход лекарственных веществ из двухслойных покрытий происходит в два этапа с максимальным высвобождением в течение двух суток. Полученные текстильные материалы с пленочным нанокомпозитным гидрогелевым покрытием могут найти применение в качестве перевязочных средств при лечении ран. Nanotechnologies using biopolymers are widely used in biomedical applications. In this work, nanocomposite hydrogels based on natural (chitosan, carboxymethylcellulose) and synthetic (polyvinyl alcohol) polymers with silver nanoparticles for application to a textile carrier have been developed. Carboxymethylcellulose dialdehyde and boric acid were used as crosslinking reagents in the creation of hydrogels. Physicochemical properties (sorption capacity in unilateral contact with the model medium, degree of swelling, vapor permeability, capillarity) of hydrogel coatings on a textile carrier, and the kinetics of the drugs release (lidocaine, dioxidine) included in the hydrogels were determined. It is shown that materials with a two-layer coating are characterized by higher sorption properties relative to saline and a longer release of drugs than materials with a single-layer coating. The release of drugs from the two-layer coatings occurs in two stages with a maximum release within two days. The obtained textile materials with a film nanocomposite hydrogel coating can be used as dressings in the treatment of wounds.

Anti-Reflection Coatings on 3D-Printed Components

The use of anti-reflection coatings on 3D-printed components to reduce both Fresnel reflections and scattering is explored. Two similar photo-initiated acrylic commercial material structures, known as Standard Clear (SC: T~60% @ λ = 800 nm) and VeroClear (VC: T~90% @ λ = 800 nm), used specifically for optical components, are examined. The refractive indices for slab samples~(5 × 5 × 0.7) cm are measured at λ = 650 nm and averaged over the slab area: n(SC)~(1.49 ± 0.04) and n(VC)~(1.42 ± 0.03). Within experimental error, novel Shore D mapping is used to show hardness distribution across the surface flats, with VC slightly harder than SC, where VC = 85.9 ± 0.3 and SC = 84.4 ± 1.3, indicating uniform hardness. A TiO2/MgF2 anti-reflection twin-layer coating is deposited onto one side of an unpolished SC slab and binds well, passing standard peeling and humidity tests. Shore hardness increases to SCCOATED = 87.5 ± 1.5. It is found to reduce the measured Fresnel reflection and surface scatter by~65% without requiring major polishing, paving the way for lower-cost high-quality optics. The demonstration of successful anti-reflection coatings will benefit all 3D-printed component finishes, permitting viable film deposition more broadly.

Analysis of the use of paint coatings to protect the hull from corrosion

The most common and reliable method of protecting a ship’s hull from corrosion is paint coatings. Paint coatings can be used to paint products of any size. In case of complete or partial destruction, the paintwork can be easily restored by tinting or completely repainting the surface. Paints and varnishes are easily combined with other methods of corrosion protection. The use of paint coatings is more economical in comparison with other types of corrosion protection. Therefore, it is currently the most common method of protecting ship hulls. In order to determine the quality, the experimental studies of various paints and varnishes were carried out. Experimental prototypes were made. The effect of low temperatures and the effect of an impending water flow on paint and coatings were considered. The main conclusions were drawn from the results of the experiments. For long-term protection from the external environment, it is necessary that the coating film should maintain high adhesion to the surface maintain continuous, have minimal water absorption, devoid of pores and be solid. Samples with a two-layer and three-layer coating of Jotun paint have the best adhesion. Satisfactory results were also obtained on samples with a three-layer coating of XC-436 enamel and with a two-layer coating of stone red.

Effect of Silver Nanoparticles on Fluorescence Intensity of Fluoreseina Dye Mixed in One Solution

Metal enhanced fluorescence (MEF) is an unequaled phenomenon of metal nanoparticle surface plasmons, when light interacts with the metal nanostructures (silver nanoparticles) which result electromagnetic fields to promote the sensitivity of fluorescence. This work endeavor to study the influence of silver nanoparticles on fluorescence intensity of Fluoreseina dye by employment mixture solution with different mixing ratio. Silver nanoparticles had been manufactured by the chemical reduction method so that Ag NP layer coating had been done by hot rotation liquid method. The optical properties of the prepared samples (mixture solution of Fluoreseina dye solutions and colloidal solution with 5 minutes prepared of Ag NPs) tested by using UV-VIS absorption and Fluorescence spectrophotometer. by using AFM, SEM testes, the structure of silver nanoparticles had been estimated. the result of this work showed that adding Ag NPs colloidal to Fluoreseina dye solution help get a significant increase in the fluorescence intensity of this dye. this study results show that its significant to recent related studies in MEF.

Research of the influence of bias voltage on the structure and residual stress in Ta/W coatings applied on a copper substrate by inverted magnetron

This paper presents the results of studying the effect of the bias voltage on a copper tube substrate on the texture and residual stresses in 4-layer Ta/W/Ta/W coatings deposited with an inverted magnetron. It is shown that, in contrast to monolayer coatings of Ta and W, in which residual stresses exceeding 2 GPa are formed on the substrate at high voltages on the substrate, stress relaxations occur in the 4-layer coating in alternating layers differing in LTEC values and in the outer W-layer of stress practically absent.

Colonic Delivery of Celastrol-Loaded Layer-by-Layer Liposomes with Pectin/Trimethylated Chitosan Coating to Enhance Its Anti-Ulcerative Colitis Effects

Herein, a flexible oral colon-targeting delivery system, mediated by electrostatic layer-by-layer alternate deposition with pectin-trimethyl chitosan (TMC) onto liposomes-loading celastrol (Cel/PT-LbL Lipo), was fabricated to enhance anti-UC efficacy. Along with layer-by-layer coating, Cel/Lipo exhibited surface charge reversal, a slight increase in particle size, and a sustained drug release profile in a simulative gastrointestinal tract medium. Based on its bilayer coating of polysaccharides, Cel/PT-LbL Lipo alleviated cytotoxicity of celastrol in colon epithelial NCM460 cells. Due to the strong mucoadhesion of TMC with mucin, PT-LbL Lipo benefited colon localization and prolonged retention ability of its payloads. Ultimately, Cel/PT-LbL Lipo significantly mitigated colitis symptoms and accelerated colitis repair in DSS-treated mice by regulating the levels of pro-inflammatory factors related to the TLR4/MyD88/NF-κB signaling pathway. Collectively, this study demonstrates that the pectin/trimethylated chitosan coating may allow for Cel/PT-LbL Lipo to function as a more beneficial therapeutic strategy for UC treatment.