Development of an Insulin Nano-Delivery System through Buccal Administration

Aim: To develop a new nano-delivery system for insulin buccal administration. Background: Biodegradable polymeric nanoparticles (PNPs) had viewed countless breakthroughs in drug delivery systems. The main objective of PNPs application in delivering and carrying different promising drugs is to make sure that the drugs being delivered to their action sites. As a result maximizing the desired effect and overcoming their limitations and drawbacks. Objectives: The main goals of this study were to produce an insulin consumable nano-delivery system for buccal administration and enhance the mucoadhesive effect in sustaining insulin release. Methods: Water in oil in water (W-O-W) microemulsion solvent evaporation technique was used for the preparation of nanoparticles consisting from positively charged poly (D, L-lactide-co-glycolide) coated with chitosan and loaded with insulin. Later, a consumable buccal film was prepared by the spin coating method and loaded with the previously prepared nanoparticles. Results: The newly prepared nanoparticle was assessed in terms of size, charge and surface morphology using a Scanning Electron Microscope (SEM), zeta potential, Atomic Force Microscope (AFM), and Fourier Transform Infra-red (FTIR) spectroscopy. An in-vitro investigation of the insulin release, from nanoparticles and buccal film, demonstrated controlled as well as sustained delivery over 6 hrs. The cumulative insulin release decreased to about (28.9%) with buccal film in comparing with the nanoparticle (50 %). Conclusion: The buccal film added another barrier for insulin release. Therefore, the release was sustained.

Fundamental Investigations on the High-Temperature Corrosion of Spinel-Forming Alumina Castables by Steel Slags

This study investigated the effect of the CaO/SiO2 mass ratio of steel slag on the corrosion behavior of spinel-forming alumina-based castables with a content of MgO (3–7 wt.%). Equiweight mixtures of castables and slags were calculated by FactSage, observed by HMTA, fired at 1350 °C, and investigated by XRD. From these results, we conclude that the presence of SiO2-rich phases accelerates the growth of the liquid phase in a narrow temperature range for the tested samples, which accelerates the degradation of castables. The static corrosion test was conducted by means of the coating method at 1450 °C. The corrosion index (IC) in the regions of castables affected by slags was calculated. Phases and phase distributions were evaluated by SEM-EDS. From these results, we conclude that for the slag with the lowest mass ratio of CaO/SiO2 (1.1), the reaction zone occurs only below the slag-refractory interface, which indicates the aggressive character of this slag.

Tin Whisker Growth Suppression Using NiO Sublayers Fabricated by Dip Coating

Whiskers are small crystalline growths, which can grow from certain metals or alloys. Reaching up to several millimeters long, whiskers have the potential to cause device failures due to short circuits and contamination by debris. Tin (Sn) is one such metal that is particularly prone to whisker development. Until the 2006 RoHS Initiative, lead (Pb) was added to tin in small amounts (up to 2%) to greatly reduce the growth of whiskers. Since then, however, industry has switched to lead-free tin solders and coatings, and the issue of whisker growth on tin has attracted new interest. A reactive-sputtering-deposited nickel oxide sublayer was shown recently to strongly suppress the growth of whiskers from an overlaying tin layer. This paper reports on using nickel oxide films, obtained by a sol–gel dip coating method, as whisker suppressing sublayers. The proposed method is simple, low-cost, and can easily be scaled up for manufacturing purposes. The properties of the sol–gel deposited nickel oxide film were examined using SEM, EDS, and Raman spectroscopy. Samples containing the nickel oxide sublayer were observed through SEM periodically over several months to examine the surfaces for whisker development, and the results show that such layers can be very effective in suppressing whisker growth.

Сравнительное исследование электрохромных свойств слоев полианилин-поликислота, нанесенных методами спрей-распыления и полива с добавлением углеродных нанотрубок

The influence of coating method (spray-coating or drop-casting onto horizontal substrate) on the electrochromic characteristics of the layers of water-soluble polyaniline-polyacid complex was investigated. It was shown that in case of addition of single-wall nanotubes the polyaniline-polyacid layers prepared by scalable spray-coating technology demonstrate high coloration speed an electrochromic efficiency.

Immobilised rGO/TiO2 Nanocomposite for Multi-Cycle Removal of Methylene Blue Dye from an Aqueous Medium

This work presents the immobilisation of titanium dioxide (TiO2) nanoparticles (NPs) and reduced graphene oxide (rGO)-TiO2 nanocomposite on glass sheets for photocatalytic degradation of methylene blue (MB) under different radiation sources such as ultraviolet and simulated solar radiation. The TiO2 NPs and rGO-TiO2 nanocomposite were synthesised through a simple hydrothermal method of titanium isopropoxide precursor followed by calcination treatment. Deposition of prepared photocatalysts was performed by spin-coating method. Additionally, ethylene glycol was mixed with the prepared TiO2 NPs and rGO-TiO2 nanocomposite to enhance film adhesion on the glass surface. The photocatalytic activity under ultraviolet and simulated solar irradiation was examined. Further, the influence of different water matrices (milli-Q, river, lake, and seawater) and reactive species (h+, •OH, and e−) on the photocatalytic efficiency of the immobilised rGO/TiO2 nanocomposite was careful assessed. MB dye photocatalytic degradation was found to increase with increasing irradiation time for both irradiation sources. The immobilisation of prepared photocatalysts is very convenient for environment applications, due to easy separation and reusability, and the investigated rGO/TiO2-coated glass sheets demonstrated high efficiency in removing MB dye from an aqueous medium during five consecutive cycles.