Hydrogels as Potential Nano-, Micro- and Macro-Scale Systems for Controlled Drug Delivery

This review is an extensive evaluation and essential analysis of the design and formation of hydrogels (HGs) for drug delivery. We review the fundamental principles of HGs (their chemical structures, physicochemical properties, synthesis routes, different types, etc.) that influence their biological properties and medical and pharmaceutical applications. Strategies for fabricating HGs with different diameters (macro, micro, and nano) are also presented. The size of biocompatible HG materials determines their potential uses in medicine as drug carriers. Additionally, novel drug delivery methods for enhancing treatment are discussed. A critical review is performed based on the latest literature reports

Nanoforest: Polyaniline Nanotubes Modified with Carbon Nano-Onions as a Nanocomposite Material for Easy-to-Miniaturize High-Performance Solid-State Supercapacitors

This article describes a facile low-cost synthesis of polyaniline nanotube (PANINT)⁻carbon nano-onion (CNO) composites for solid-state supercapacitors. Scanning electron microscopic (SEM) analyses indicate a uniform and ordered composition for the conducting polymer nanotubes immobilized on a thin gold film. The obtained nanocomposites exhibit a brush-like architecture with a specific capacitance of 946 F g−1 at a scan rate of 1 mV s−1. In addition, the nanocomposites offer high conductivity and a porous and well-developed surface area. The PANINT⁻CNO nanocomposites were tested as electrodes with high potential and long-term stability for use in easy-to-miniaturize high-performance supercapacitor devices

Evaluation of the Covalent Functionalization of Carbon Nano-Onions with Pyrene Moieties for Supercapacitor Applications

Herein, we report the surface functionalization of carbon nano-onions (CNOs) through an amidation reaction that occurs between the oxidized CNOs and 4-(pyren-4-yl)butanehydrazide. Raman and Fourier transform infrared spectroscopy methods were used to confirm the covalent functionalization. The percentage or number of groups in the outer shell was estimated with thermal gravimetric analysis. Finally, the potential applications of the functionalized CNOs as electrode materials in supercapacitors were evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. Functionalization increased the specific capacitance by approximately 138% in comparison to that of the pristine CNOs, while acid-mediated oxidation reduced the specific capacitance of the nanomaterial by 24%

A Reinvestigation of the Electrochemical Behavior of SC\u3csub\u3e3\u3c/sub\u3eN@C\u3csub\u3e80\u3c/sub\u3e

Electrochemical studies of the Ih isomer of Sc3N@C80 in acetonitrile/toluene solvent mixture were performed. Controlled potential electrolysis was used to increase the solubility of the compounds via reduction and all CV and DPV investigations were performed under the vapor pressure of the prevailing solvents. The reduction and oxidation processes were found to be electrochemically quasi-reversible by cyclic voltammetry techniques, suggestive of a nondegenerate LUMO and accessible LUMO + 1. The electrochemical properties of Sc3N@C80 (Ih) were comparatively discussed with our previous results performed in o-dichlorobenzene and results published by other authors in an acetonitrile/toluene solvent mixture

Microwave-Assisted Synthesis of Modified Glycidyl Methacrylate–Ethyl Methacrylate Oligomers, Their Physico-Chemical and Biological Characteristics

In this study, well-known oligomers containing ethyl methacrylate (EMA) and glycidyl methacrylate (GMA) components for the synthesis of the oligomeric network [P(EMA)-co-(GMA)] were used. In order to change the hydrophobic character of the [P(EMA)-co-(GMA)] to a more hydrophilic one, the oligomeric chain was functionalized with ethanolamine, xylitol (Xyl), and L-ornithine. The oligomeric materials were characterized by nuclear magnetic resonance and Fourier transform infrared spectroscopy, scanning electron microscopy, and differential thermogravimetric analysis. In the final stage, thanks to the large amount of -OH groups, it was possible to obtain a three-dimensional hydrogel (HG) network. The HGs were used as a matrix for the immobilization of methylene blue, which was chosen as a model compound of active substances, the release of which from the matrix was examined using spectrophotometric detection. The cytotoxic test was performed using fluid extracts of the HGs and human skin fibroblasts. The cell culture experiment showed that only [P(EMA)-co-(GMA)] and [P(EMA)-co-(GMA)]-Xyl have the potential to be used in biomedical applications. The studies revealed that the obtained HGs were porous and non-cytotoxic, which gives them the opportunity to possess great potential for use as an oligomeric network for drug reservoirs in in vitro application

Nanostructured Carbon Catalyst for Amide Coupling Reactions under Microwave Heating in the Absence of a Solvent

Carbon nanostructures offer a perfect link between nanoscale materials and organic molecules, making them an ideal platform for molecular catalysts. Herein, an efficient, straightforward, and high-yield synthetic approach is described to synthesize aryl boronic acid containing the pyrene moiety that is noncovalently immobilized by π–π interaction to carbon nano-onions’ surface. The nanostructured carbon material catalyzes the direct amide coupling reaction under microwaved heating in the absence of a solvent. The multilayered structures of carbon nano-onions ensure high thermal stability, and simultaneously, they are excellent microwaved absorbers, which reduce energy consumption. The absorption of microwaved radiation by the nanostructured carbon catalyst effectively influences yield of the catalytic reaction, which is up to 94%. Additionally, the recovery of catalytic material is straightforward, and the mass losses are negligible. Microwave heating in a solvent-free condition simplifies the reaction and reduces the amount of waste, which, in turn, depletes the environmental impact