Rapid preparation and antimicrobial activity of polyurea coatings with RE-Doped nano-ZnO

Combatting biofilms in potable water systems: A comprehensive overview to ensuring industrial water safety

Biofilm formation in industrial potable water systems, encompassing applications such as drinking, emergency showers, firefighting and sanitary appliances, presents a multifaceted challenge that has significant implications for both equipment efficiency and human health. These microbial communities, comprised of bacteria, fungi and protozoa, adhere to surfaces and are embedded within an extracellular matrix, primarily of polysaccharide origin. The formation and persistence of these biofilms can lead to reduced system efficiency and potential health risks due to microbial-induced corrosion, contamination and waterborne pathogens. This review delves into the physicochemical and microbial factors promoting biofilm growth in these systems and elucidates contemporary strategies for their control and eradication. By harnessing advanced methodologies, including state-of-the-art filtration, disinfection techniques and predictive monitoring, stakeholders can proactively address biofilm-related challenges. The emphasis of this comprehensive overview is on the interdisciplinary nature of biofilm growth, combining insights from microbiology, engineering and water chemistry to pave the way for an integrative approach to ensuring consistent industrial water quality.

Biofilms Controlling in Industrial Cooling Water Systems: A Mini-Review of Strategies and Best Practices

Biofilm formation and growth is a significant concern for water treatment professionals, as it can lead to the contamination of water systems and pose a threat to public health. Biofilms are complex communities of microorganisms that adhere to surfaces and are embedded in an extracellular matrix of polysaccharides and proteins. They are notoriously difficult to control, as they provide a protective environment for bacteria, viruses, and other harmful organisms to grow and proliferate. This review article highlights some of the factors that favor biofilm growth, as well as various strategies for controlling biofilm in water systems. Adopting the best available technologies, such as wellhead protection programs, proper industrial cooling water system maintenance, and filtration and disinfection, can prevent the formation and growth of biofilms in water systems. A comprehensive and multifaceted approach to biofilm control can reduce the occurrence of biofilms and ensure the delivery of high-quality water to the industrial process.

Electrospun nanofibers for medical face mask with protection capabilities against viruses: State of the art and perspective for industrial scale-up

Face masks have proven to be a useful protection from airborne viruses and bacteria, especially in the recent years pandemic outbreak when they effectively lowered the risk of infection from Coronavirus disease (COVID-19) or Omicron variants, being recognized as one of the main protective measures adopted by the World Health Organization (WHO). The need for improving the filtering efficiency performance to prevent penetration of fine particulate matter (PM), which can be potential bacteria or virus carriers, has led the research into developing new methods and techniques for face mask fabrication. In this perspective, Electrospinning has shown to be the most efficient technique to get either synthetic or natural polymers-based fibers with size down to the nanoscale providing remarkable performance in terms of both particle filtration and breathability. The aim of this Review is to give further insight into the implementation of electrospun nanofibers for the realization of the next generation of face masks, with functionalized membranes via addiction of active material to the polymer solutions that can give optimal features about antibacterial, antiviral, self-sterilization, and electrical energy storage capabilities. Furthermore, the recent advances regarding the use of renewable materials and green solvent strategies to improve the sustainability of electrospun membranes and to fabricate eco-friendly filters are here discussed, especially in view of the large-scale nanofiber production where traditional membrane manufacturing may result in a high environmental and health risk.

In Vitro Antimicrobial and Anticancer Peculiarities of Ytterbium and Cerium Co-Doped Zinc Oxide Nanoparticles

Zinc oxide nanoparticles (ZnO NPs) are a promising platform for their use in biomedical research, especially given their anticancer and antimicrobial activities. This work presents the synthesis of ZnO NPs doped with different amounts of rare-earth ions of ytterbium (Yb) and cerium (Ce) and the assessment of their anticancer and antimicrobial activities. The structural investigations indicated a hexagonal wurtzite structure for all prepared NPs. The particle size was reduced by raising the amount of Ce and Yb in ZnO. The anticancer capabilities of the samples were examined by the cell viability MTT assay. Post 48-h treatment showed a reduction in the cancer cell viability, which was x = 0.00 (68%), x = 0.01 (58.70%), x = 0.03 (80.94%) and x = 0.05 (64.91%), respectively. We found that samples doped with x = 0.01 and x = 0.05 of Yb and Ce showed a better inhibitory effect on HCT-116 cancer cells than unadded ZnO (x = 0.00). The IC₅₀ for HCT-116 cells of Ce and Yb co-doped ZnO nanoparticles was calculated and the IC₅₀ values were x = 0.01 (3.50 µg/mL), x = 0.05 (8.25 µg/mL), x = 0.00 (11.75 µg/mL), and x = 0.03 (21.50 µg/mL). The treatment-doped ZnO NPs caused apoptotic cell death in the HCT-116 cells. The nanoparticles showed inhibitory action on both C. albicans and E. coli. It can be concluded that doping ZnO NPs with Yb and Ce improves their apoptotic effects on cancer and microbial cells.

A Comparative Study on the Self-Healing Characterizations and Formulation Optimization of Polyurea Coating

Self-healing materials, especially self-healing polyurea/polyurethane, to replace traditional coating has been of increasing interest in the past decade. The frequency of regular maintenance work can also be reduced as the coating is capable of forming bonds at ruptured sites. This reduces the cost of maintenance and the risk involved in workers engaging in maintenance work. The extremely short curing time of polyurea coating could potentially outweigh the cost due to its short down time. With a high self-healing efficiency, self-healing polyurea could be the ultimate choice of protective coating. This report aims to find the optimum formulation for fabrication of polyurea with a high self-healing efficiency. This is conducted by changing the composition of the components chosen for formulation of polyurea. The choice of isocyanate and amine is varied to explore its impact on chain mobility and microphase separation, which are important factors affecting self-healing efficiency. A series of characterizations, including ATR-FTIR, DSC, optical microscope and mechanical tester, is used to analyze the factors affecting the self-healing efficiency of fabricated polyurea and to eventually determine the best formulation. The ideal formulation of toluene 2,4 diisocyanate-amine (TDI-P1000) polyurea managed to achieve a self-healing of 42%. Further studies could be done to include multiple healing mechanisms after different area of polyurea to boost its self-healing efficiency after repeated healing.

Mini-Review of Self-Healing Mechanism and Formulation Optimization of Polyurea Coating

Self-healing polymers are categorized as smart materials that are capable of surface protection and prevention of structural failure. Polyurethane/polyurea, as one of the representative coatings, has also attracted attention for industrial applications. Compared with polyurethane, polyurea coating, with a similar formation process, provides higher tensile strength and requires shorter curing time. In this paper, extrinsic and intrinsic mechanisms are reviewed to address the efficiency of the self-healing process. Moreover, formulation optimization and strategic improvement to ensure self-healing within a shorter period of time with acceptable recovery of mechanical strength are also discussed. The choice and ratio of diisocyanates, as well as the choice of chain extender, are believed to have a crucial effect on the acceleration of the self-healing process and enhance self-healing efficiency during the preparation of polyurea coatings.

Structure-Dependent Nontraditional Intrinsic Fluorescence of Aliphatic Hyperbranched Polyureas

The nontraditional intrinsic fluorescence (NTIF) of polymers containing heteroatoms has gained considerable attention due to its promising applications in label-free bioimaging. Aliphatic hyperbranched polyureas (aBPUs), which have recently shown great promise in the field of nanomedicine, bear controllable urea groups distributed on the branch points and thus are potential candidate luminogens. However, their NTIF properties and how their structures influence the NTIF properties have not been illustrated yet. Here, we addressed these issues by synthesizing a series of aBPUs with different degrees of branching (DBs) or different modifications. aBPUs exhibited an obvious NTIF phenomenon and with the increase of DBs, the NTIF enhanced as well. Chemical modifications either at the branching ends or in the interior of aBPUs could affect the NTIF performances, which were highly dependent on the types of modification. Disruption of the intra-/intermolecular hydrogen-bonding interactions decreased the NTIF. In addition, poly(ethylene glycol) (PEG)-modified aBPUs could self-assemble into nanospheres, and the formation of nanoassembly led to 89% enhancement on NTIF compared with the homogeneous solution of aBPUs-PEG in dimethylformamide (DMF). Finally, aBPUs-PEG nanoassembly demonstrated a capability in realizing label-free material imaging in vitro. These results shed light on the rational design of the polymer structures to achieve desired fluorescence with unconventional luminophores.

Studies Regarding the Antibacterial Effect of Plant Extracts Obtained from Epilobium parviflorum Schreb

The present study was carried out to develop an experimental endodontic irrigant solution based on plant extracts obtained from Epilobium parviflorum Schreb. that largely replenish the properties of the usual antiseptics used in dentistry. Background: This study investigated the phytochemical contents of plant extracts obtained from Epilobium parviflorum Schreb. and their potential antibacterial activity. Methods: Identification and quantification of biologically active compounds were made by UV field photo spectrometry, adapting the Folin-Ciocalteu test method. Antibacterial activity was tested on pathological bacterial cultures collected from tooth with endodontic infections using a modified Kirby-Bauer diffuse metric method. Results: Polyphenols and flavonoids were present in all plant extracts; the hydroalcoholic extract had the highest amount of polyphenols—17.44 pyrogallol equivalent (Eq Pir)/mL and flavonoids—3.13 quercetin equivalent (Eq Qr)/mL. Plant extracts had antibacterial activity among the tested bacterial species with the following inhibition diameter: White Staphylococcus (16.5 mm), Streptococcus mitis (25 mm), Streptococcus sanguis (27 mm), Enterococcus faecalis (10 mm). Conclusions: All plant extracts contain polyphenols and flavonoids; the antibacterial activity was in direct ratio with the amount of the bioactive compounds.