Cardiovascular diseases are the most distributed cause of death worldwide. Stenting of arteries as a percutaneous transluminal angioplasty procedure became a promising minimally invasive therapy based on re-opening narrowed arteries by stent insertion. In order to improve and optimize this method, many research groups are focusing on designing new or improving existent stents. Since the beginning of the stent development in 1986, starting with bare-metal stents (BMS), these devices have been continuously enhanced by applying new materials, developing stent coatings based on inorganic and organic compounds including drugs, nanoparticles or biological components such as genes and cells, as well as adapting stent designs with different fabrication technologies. Drug eluting stents (DES) have been developed to overcome the main shortcomings of BMS or coated stents. Coatings are mainly applied to control biocompatibility, degradation rate, protein adsorption, and allow adequate endothelialization in order to ensure better clinical outcome of BMS, reducing restenosis and thrombosis. As coating materials (i) organic polymers: polyurethanes, poly(ε-caprolactone), styrene-b-isobutylene-b-styrene, polyhydroxybutyrates, poly(lactide-co-glycolide), and phosphoryl choline; (ii) biological components: vascular endothelial growth factor (VEGF) and anti-CD34 antibody and (iii) inorganic coatings: noble metals, wide class of oxides, nitrides, silicide and carbide, hydroxyapatite, diamond-like carbon, and others are used. DES were developed to reduce the tissue hyperplasia and in-stent restenosis utilizing antiproliferative substances like paclitaxel, limus (siro-, zotaro-, evero-, bio-, amphi-, tacro-limus), ABT-578, tyrphostin AGL-2043, genes, etc. The innovative solutions aim at overcoming the main limitations of the stent technology, such as in-stent restenosis and stent thrombosis, while maintaining the prime requirements on biocompatibility, biodegradability, and mechanical behavior. This paper provides an overview of the existing stent types, their functionality, materials, and manufacturing conditions demonstrating the still huge potential for the development of promising stent solutions.

A fragment of mortar from the pedestal ruin belonging to the central statue in Forum Vetus, Ulpia Traiana archaeological site, Romania, was investigated. The ruin is well-documented and unrestored, and radiocarbon dating was deemed suitable to determine its moment of construction. Preliminary analyses were used to establish the composition of the material and the sources of carbon-14, selecting the most reliable fraction for radiocarbon dating by the AMS method. Although sampling was carried out according to the recommendations, a younger apparent age was obtained than that expected. This is in fact a concrete-like mortar according to the analyses, and the phenomenon of delayed hardening of mortar in masonry was detected. The difference between the real and apparent ages quantifies this phenomenon. X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, differential scanning calorimetry with thermogravimetric analysis, and gamma spectrometry were used. Pyrogenic calcium carbonate and carbonates from calcium silicate/calcium aluminate hydrates were the only forms present in mini-nodules/lumps. The reactivation of binder calcite or geogenic calcite, the other problems encountered when dating mortars, were not spotted. This case study highlights the limitations of the radiocarbon dating method, and we introduce gamma spectrometry as a technique for additional investigations into direct exposure to the environment or the origins of raw materials.

Alumina ceramics were obtained from three different alumina sources, A1–A3, with various rare-earth dopants (La₂O₃–La, Nd₂O₃–Nd, and Y₂O₃–Y), concentration levels (500 and 1000 ppm) and synthesizing routes (1500 °C, 1815 °C and cold plasma-P). Absorption (A) and density (ρ in text, rho in images) were measured, resulting in a complex, multivariate database. Principal Component Analysis (PCA) was run with the aim of deducing relationships between variables (alumina source, dopant level, thermal processing route, A and ρ), observations, and between variables and observations. A total of 206 Scanning Electron Microscopy (SEM) micrographs were recorded at various scales and the corresponding images were processed to quantify the microstructural features. Two techniques of edge detection were used; Fractal Dimension (FD) was calculated for each micrograph and results were compared. Various scales of the micrographs prevented us from using any other approach, such as simply measuring the grains or obtaining shape parameters. The initial database was extended by including FDs and PCA was run again. We found that plasma processing is positively correlated to A and negatively correlated to both temperature (T) and ρ; La ceramics have an opposite behavior to Y and Nd ceramics. FD successfully explained observations being correlated, mainly, to Y, Nd and, to a lesser extent, to La. FD proved that it is a reliable and simple approach to quantifying microstructural features when comparing highly different, noisy micrographs.

In recent decades, applications related to sensing have grown increasingly, transforming and expanding their fields into innovative research. Lately, researchers have demonstrated that immobilizing metal nanoparticles on glass-based platforms may render innovative perspectives for sensing applications. As a result, the focus of this study was to develop glass-based platforms functionalized with silver nanoparticles, intending them to be utilized in sensing applications. The purpose of using glass-based platforms is due to their availability and eco-friendly features, which will make them suitable for such applications. The study uses a glass-based platform functionalized/modified with organosilanes (such as mercaptoalkyl trialkoxysilane), which can have a high affinity for Ag NPs. By decorating the glass surface with Ag NPs, it becomes active for the adsorption of the mercapto derivatives and further usage in sensing applications (specific drugs with an antitumoral, anti-hypertensive, antiarthritic role, neurotransmitters, etc.) but also for specific classes of pollutants for environmental applications. Therefore, the desired purpose of this study was to develop glass-based platforms decorated with Ag NPs and their further use in the selective adsorption of thioderivatives (cysteine was selected as a model component) even from a mixture of amino acids (cysteine, alanine, and threonine).

The threats leading to the extinction of humanity accelerate the evolution and development of materials that are capable of providing conditions for preserving health and, implicitly, life. In our work, we developed drug delivery systems based on mesoporous silica which can deliver an antibiotic, bacitracin, in a more controlled manner. The synthesis of the FDU-12 was performed through a sol–gel method and alternatively functionalized with -NH₂ groups or with poly(N-acryloylmorpholine) chains. The loading of bacitracin was performed using the vacuum-assisted method we successfully used to load these mesoporous materials preferentially within the pores as proved by the TGA-DSC results. The release was performed in two types of simulated body fluid (SBF) and this process was evaluated with chromatographic method using UV detection. The obtained data were fitted in three mathematical models of kinetic drug release (Weibull model, Korsmeyer–Peppas model, and nonlinear regression). The antimicrobial evaluation demonstrated that bacitracin-loaded FDU-12 formulations exhibited strong activity against both reference and clinical Staphylococcus strains. At sub-inhibitory concentrations, all formulations significantly reduced microbial adherence and biofilm formation, although certain strain-dependent stimulatory effects were observed. Furthermore, exposure to sub-MIC levels modulated the production of soluble virulence factors (hemolysins, lipase, and amylase), in a formulation- and strain-dependent manner, underscoring the ability of surface-functionalized FDU-12 carriers to influence bacterial pathogenicity while enhancing antimicrobial efficacy.