Search

Background: This study aimed to determine, at the phenotypic and molecular levels, resistance and virulence markers in Candida spp. isolated from community-acquired infections in Bucharest outpatients during 2021, and to demonstrate the efficiency of alternative solutions against them based on silver nanoparticles (AgNPs). Methods: A total of 62 Candida spp. strains were isolated from dermatomycoses and identified using chromogenic culture media and MALDI-TOF MS, and then investigated for their antimicrobial resistance and virulence markers (VMs), as well as for metabolic enzymes using enzymatic tests for the expression of soluble virulence factors, their biofilm formation and adherence capacity on HeLa cells, and PCR assays for the detection of virulence markers and the antimicrobial activity of alternative solutions based on AgNPs. Results: Of the total of 62 strains, 45.16% were Candida parapsilosis; 29.03% Candida albicans; 9.67% Candida guilliermondii; 3.22% Candida lusitaniae, Candia pararugosa, and Candida tropicalis; and 1.66% Candida kefyr, Candida famata, Candida haemulonii, and Candida metapsilosis. Aesculin hydrolysis, caseinase, and amylase production were detected in the analyzed strains. The strains exhibited different indices of adherence to HeLa cells and were positive in decreasing frequency order for the LIP1, HWP1, and ALS1,3 genes (C. tropicalis/C. albicans). An inhibitory effect on microbial growth, adherence capacity, and on the production of virulence factors was obtained using AgNPs. Conclusions: The obtained results in C. albicans and Candida non-albicans circulating in Bucharest outpatients were characterized by moderate-to-high potential to produce VMs, necessitating epidemiological surveillance measures to minimize the chances of severe invasive infections. [ABSTRACT FROM AUTHOR]

This review covers recent compositions of bioactive glass, with a specific emphasis on both inorganic and organic materials commonly utilized as matrices for injectable materials. The major objective is to highlight the predominant bioactive glass formulations and their clinical applications in the biomedical field. Previous studies have highlighted the growing interest among researchers in bioactive glasses, acknowledging their potential to yield promising outcomes in this field. As a result of this increased interest, investigations into bioactive glass have prompted the creation of composite materials and, notably, the development of injectable composites as a minimally invasive method for administering the material within the human body. Injectable materials have emerged as a promising avenue to mitigate various challenges. They offer several advantages, including minimizing invasive surgical procedures, reducing patient discomfort, lowering the risk of postoperative infection and decreasing treatment expenses. Additionally, injectable materials facilitate uniform distribution, allowing for the filling of defects of any shape. [ABSTRACT FROM AUTHOR]

Food safety and quality are major concerns in the food industry. Despite numerous studies, polyethylene remains one of the most used materials for packaging due to industry reluctance to invest in new technologies and equipment. Therefore, modifications to the current materials are easier to implement than adopting whole new solutions. Antibacterial activity can be induced in low-density polyethylene films only by adding antimicrobial agents. ZnO nanoparticles are well known for their strong antimicrobial activity, coupled with low toxicity and UV shielding capability. These characteristics recommend ZnO for the food industry. By incorporating such safe and dependable antimicrobial agents in the polyethylene matrix, we have obtained composite films able to inhibit microorganisms' growth that can be used as packaging materials. Here we report the obtaining of highly homogenous composite films with up to 5% ZnO by a melt mixing process at 150 °C for 10 min. The composite films present good transparency in the visible domain, permitting consumers to visualize the food, but have good UV barrier properties. The composite films exhibit good antimicrobial and antibiofilm activity from the lowest ZnO composition (1%), against both Gram-positive and Gram-negative bacterial strains. The homogenous dispersion of ZnO nanoparticles into the polyethylene matrix was assessed by Fourier transform infrared microscopy and scanning electron microscopy. The optimal mechanical barrier properties were obtained for composition with 3% ZnO. The thermal analysis indicates that the addition of ZnO nanoparticles has increased thermal stability by more than 100 °C. The UV-Vis spectra indicate a low transmittance in the UV domain, lower than 5%, making the films suitable for blocking photo-oxidation processes. The obtained films proved to be efficient packaging films, successfully preserving plum (Rome) tomatoes for up to 14 days. [ABSTRACT FROM AUTHOR]

Progress in composite materials has led to their use in applications where improved mechanical and resistance characteristics are required. Most composites are obtained in such a way that they present specific mechanical properties and/or have the role of both a thermal conductor and insulator; these properties are important, specific, specialized, and useful. The advantages of these materials compared to the classic ones are as follows: low weight, high resistance to wear and corrosion, and mechanical characteristics consistent with the subsequent use of the product. The slightly high costs of these materials are justified by their precision, the quality of the products obtained, and the fact that their use leads to increased reliability, maintenance, and, in the cases of the automotive and aeronautical industries, reduced energy consumption. This paper aims to bring to readers' attention the latest research related to glass fibre-reinforced composite materials in transport-related applications, such as automotive and aeronautic applications, including the manufacturing of unmanned aerial vehicles (UAVs). Considering the long period of use, the recycling and reuse of composite materials used in aeronautical transport is a must considering the environmental aspects and the need of achieving a circular economy. In recent years, considerable efforts have been made to find new alternatives to improve the performance and durability of materials in the aeronautical transport sector. [ABSTRACT FROM AUTHOR]

This study investigated the solubility of poly(lactic acid) (PLA) in various solvents (to achieve an 8 % (w/v) polymer solution) and its impact on the morphology of electrospun PLA nanofibers. Several solvents, such as dichloromethane (DCM), chloroform (CHL), tetrahydrofuran (THF), acetone (AC), acetonitrile (ACTNR), dimethylformamide (DMF), dimethylacetamide (DMAc), ethylene glycol (ETGLY), distilled water (WATER), methanol (MEOH), formic acid (FA), and n‐hexane (NHX) were used in their pure and binary forms at several ratios (4 : 1, 2 : 1, 1 : 1, 1 : 2, 1 : 3, and 1 : 4). The study aims to explore the correlation between PLA solubility and its electrospinnability using solvents mapped from the Teas graph across different parameter zones and chemical groups. Hansen solubility parameters, including dispersion cohesion fractional solubility parameter (fd), the polar cohesion fractional solubility parameter (fp) was employed to identify the most effective solvents for PLA dissolution. Teas graph analysis highlighted a correlation between PLA solubility and solvent proximity to Hansen solubility parameters. Additionally, the solubility time varied between 1 hour and 24 hours. Polar solvents such as DCM, CHL, THF, ACTNR, and FA were able to dissolve 8 % (w/v) of PLA at different times, but only very high and effective dissolution of PLA was achieved in pure DCM and CHL whereas FA dissolved PLA in 24 hours, which resulted in the slowest solubility rate. Several structures of nanofibers, such as smooth, heterogenous, porous, fibrous, and beaded, were observed and discussed accordingly in terms of solvent type and ratio. The average nanofiber diameter ranged between 0.18 μm and 3.81 μm. Moreover, physical tests, including surface tension, density, viscosity, and conductivity, were conducted on solvent systems and CHL displayed higher viscosity, while ACTNR had the lowest viscosity and highest conductivity among pure solvents. According to the results of our study, it is possible to design further studies with the aim of deciding which solvents or binary forms should be applied to dissolve PLA within a certain time. The desired structure can be easily arranged to be used as a filter, biomimicking tissue environment, drug delivery system, or extra. [ABSTRACT FROM AUTHOR]

Development of efficient controlled local release of drugs that prevent systemic side effects is a challenge for anti-osteoporotic treatments. Research for new bone-regeneration materials is of high importance. Strontium (Sr) is known as an anti-resorptive and anabolic agent useful in treating osteoporosis. In this study, we compared two different types of synthesis used for obtaining nano hydroxyapatite (HA) and Sr-containing nano hydroxyapatite (SrHA) for bone tissue engineering. Synthesis of HA and SrHA was performed using co-precipitation and hydrothermal methods. Regardless of the synthesis route for the SrHA, the intended content of Sr was 1, 5, 10, 20, and 30 molar %. The chemical, morphological, and biocompatibility properties of HA and SrHA were investigated. Based on our results, it was shown that HA and SrHA exhibited low cytotoxicity and demonstrated toxic behavior only at higher Sr concentrations. [ABSTRACT FROM AUTHOR]

The aim of this study is to decorate a glass surface with silver nanoparticles (AgNPs) and further prove its efficiency in the removal of some thio-derivatives—potential pollutants from water. Therefore, grafting the surface of glass-based platforms with AgNPs will strongly influence their interaction with other substances or molecules. The most commonly used molecules for glass-based platform functionalization/modification are organosilanes. In this case, the main interest is in thioalkyl organosilanes because, after silanization, the thio (-SH) functional groups that have a high affinity for AgNPs can intermediate their binding on the surface. By decorating the glass platforms with AgNPs, these surfaces become active for the adsorption of dyes from wastewater. Certainly, in this case, the dyes must bear -SH groups to ensure a high affinity for these surfaces. Therefore, the desired purpose of this study was to develop glass-based platforms decorated with AgNPs able to bind model molecules—dyes from aqueous media (dithizone—DIT and thioindigo—TIO), with these platforms being potentially used for environmental applications. [ABSTRACT FROM AUTHOR]

The biodeterioration of the natural surface on monuments, historical buildings, and even public claddings brings to the attention of researchers and historians the issues of conservation and protection. Natural stones undergo changes in their appearance, being subjected to deterioration due to climatic variations and the destructive action of biological systems interfering with and living on them, leading to ongoing challenges in the protection of the exposed surfaces. Nanotechnology, through silver nanoparticles with strong antimicrobial effects, can provide solutions for protecting natural surfaces using specific coupling agents tailored to each substrate. In this work, surfaces of two common types of natural stone, frequently encountered in landscaping and finishing works, were modified using siloxane coupling agents with thiol groups. Through these agents, silver nanoparticles (AgNPs) were fixed, exhibiting distinct characteristics, and subjected to antimicrobial analysis. This study presents a comparative analysis of the efficiency of coupling agents that can be applied to a natural surface with porous structures, when combined with laboratory-obtained silver nanoparticles, in reducing the formation of microbial biofilms, which are a main trigger for stone biodeterioration. [ABSTRACT FROM AUTHOR]