Search Results (53)

Natural zeolites are highly effective adsorbents that can remove various metal cations which would otherwise contaminate the environment. However, different metal cations (Cu, Zn, and Ag) within their lattice or quaternary long-chain surfactant cations on their surface modify their affinity towards hazardous anions and promote antibacterial activity in natural zeolites. Specifically, natural zeolites in their non-modified form lack intrinsic antibacterial characteristics. NZ is the most widespread natural zeolite. This review presents the antibacterial efficiency of NZ containing transition metals, nano oxides, and organics. This effect is nonspecific and primarily driven by the nutritional makeup of the medium rather than the species of pathogenic bacteria under study. Studies on using NZ-based disinfectants to clean up contaminated water and soil and using modified and purified NZ to protect health are also considered. By eliminating toxic ions and, when modified by these toxic cations, removing pathogens from the environment, natural NZ can serve a dual function, providing it with the distinctive characteristics of a sustainable material. Full article

While conventional sericulture has developed effective disinfection methods, the increasing demand for silk and pupae is driving mechanization, potentially altering or introducing silkworm pathogens. New disinfection strategies are essential for sustainable sericulture production. This study first investigated the bacterial community differences between conventional and mechanized silkworm-rearing environments. Then, under the mechanized environment, we evaluated three commercially available disinfectants with different mechanisms: hypochlorous acid (HClO), nano platinum-polyhexamethylene guanide (Pt-PHMG), and medium-chain fatty acids (MCFA). Our results indicated significant bacterial differences between the two environments, with potential pathogenic bacteria present in both environments. Moreover, the bacterial communities remained relatively stable, while conventional disinfection methods were less effective in mechanized conditions. In contrast, regardless of whether they were applied before or after silkworm rearing, all three disinfectants demonstrated significant efficacy, with the total environmental bacterial load reduced by approximately 0.5 to 1 order of magnitude after application. Among them, Pt-PHMG exhibited the best performance by inhibiting pathogens such as Staphylococcus, Enterococcus, and Bacillus, followed by MCFA and HClO. The results also suggested a need for stronger disinfection strategies after silkworm rearing. These findings not only provide important hygiene practices to ensure mechanized silkworm rearing, but also offer valuable insights for the future development of disinfection strategies in modern sericulture. Full article

Hospital-acquired infections (HAIs) previously focused mainly on multidrug-resistant (MDR) bacteria, with less attention on viruses. The COVID-19 pandemic highlighted the importance of controlling viral infections. Human rhinoviruses (HRVs) are among the viruses responsible for HAIs. HRVs are non-enveloped viruses that infect the upper airways after airborne or direct transmission. Due to their lack of a membrane envelope, HRVs exhibit moderate resistance to commonly applied alcoholic disinfectants. Therefore, there is a significant need to develop alternative disinfection and hand sanitation strategies to control HRV infections in healthcare settings without posing a risk to human health. The antimicrobial activity and safety of rhamnolipids and rhamnolipids nano-micelles (RMN) against MDR-bacteria and several viruses, including SARS-CoV-2, were confirmed recently. Also, we previously demonstrated the superior antimicrobial activity of RMN over rhamnolipids. In the current study, molecular docking demonstrated the weak interactions of rhamnolipids with HRV-1A (minor group) compared to HRV-14 (major group), suggesting a superior antiviral activity of rhamnolipids towards major group rhinoviruses. To biologically validate these data, RMN was prepared and characterized, and then antiviral activity against HRV-16 (major group) and HRV-1B (minor group) infection of HeLa cells was assessed. RMN showed a complete inhibition of HRV-16 infection with recovery of 100% of HeLa cell viability. In contrast, only partial inhibition of HRV-1B infection with approximately 50% protection against infection was observed. Therefore, RMN might be recommended as a disinfectant and/or a hand sanitizer component to control the spread of RVs in hospital care settings or elsewhere to reduce the incidence of respiratory infections. Full article

The continuous discovery of novel effective antibacterial agents using nano-based materials is of high significance. In this study, we utilized Polymerylated divalent-metal-doped ferrite nanoparticles (PMFe₂O₄ NPs) and studied their antibacterial inhibition effects. Different panels of PVP- and PEG-coated metal-doped MFe₂O₄ (M ≅ Co, Ni, and Zn) were prepared via the Ko-precipitation Hydrolytic Basic (KHB) methodology and thoroughly analyzed using TEM, XRD, FTIR, and VSM. The as-synthesized doped ferrites displayed stable quasi-spherical particles (7–15 nm in size), well-ordered crystalline cubic spinel phases, and high-saturation magnetizations reaching up to 68 emu/g. The antibacterial efficacy of the doped ferrites was then assessed against a Gram-negative E. coli bacterial strain. The results demonstrated that both metal doping and polymer functionalization influence the antimicrobial efficacies and performance of the ferrite NPs. The presence of the PVP polymer along with the divalent metal ions, particularly Co and Ni, resulted in the highest antibacterial inhibition and effective inactivation of the bacterial cells. The antibacterial performance was as follows: PVP-CoFe₂O₄ > PVP-NiFe₂O₄ > PVP-ZnFe₂O₄. Lastly, cell viability assays conducted on human breast fibroblast (HBF) cells confirmed the good safety profiles of the doped ferrites. These interesting results demonstrate the distinctive inhibitory features of the biocompatible metal-doped ferrites in enhancing bacterial killing and highlights their promising potential as effective antimicrobial agents, with possible applications in areas such as water disinfection, biomedical devices, and antimicrobial coatings. Full article

Objectives: The synergistic effect of shock wave-enhanced emission photoacoustic streaming (SWEEPS) and antimicrobial photodynamic therapy (aPDT) in mandibular molar root canal disinfection remains underexplored, particularly against dual-species biofilms that better simulate clinical conditions. This study evaluates their combined antimicrobial efficacy against Enterococcus faecalis and Candida albicans biofilms and assesses potential tooth discoloration caused by riboflavin and nano-curcumin. Materials and Methods: The mesiobuccal canals of 57 extracted mandibular molars were inoculated with E. faecalis and C. albicans biofilms. The antimicrobial effects were assessed using riboflavin or nano-curcumin with a 450 nm diode laser (BDL), SWEEPS, or their combinations, compared to 5.25% NaOCl (positive control) and saline (negative control). Biofilm reduction was quantified by colony-forming units (CFUs/mL), and discoloration was evaluated using the ΔE metric in the CIE L*a*b* color space. Results: Both microorganisms showed a significant decrease in colony numbers in all experimental groups compared to the negative control (p < 0.001), except for E. faecalis, where no significant difference was observed between the riboflavin/nano-curcumin groups and the negative control. Combining riboflavin or nano-curcumin with SWEEPS or BDL significantly enhanced antimicrobial efficacy compared to individual treatments (p < 0.001). The combined photodynamic therapy and SWEEPS groups showed the lowest colony counts. The ΔE values were, on average, 1.81 for riboflavin and 1.09 for nano-curcumin. Conclusions: The combination of SWEEPS and aPDT effectively reduces E. faecalis and C. albicans biofilms in molars, supporting its potential as an adjunct in endodontic disinfection. Minimal discoloration further highlights its clinical applicability. Full article

Understanding cellular interaction with nanomaterials represents a subject of great interest for the validation of new diagnostic and therapeutic tools. A full characterization of a designed product includes the evaluation of its impact on specific biological systems, including the study of cell behavior as a response to that particular interaction. Copper and copper-based nanoparticles (CuO NPs) have emerged as valuable building blocks for various biomedical applications such as antibacterial and disinfecting agents for infectious diseases, and the evaluation of the metabolism of food, including the iron required for proteins and enzymes or as drug delivery systems in cancer therapy. In this study, the biological impact of manganese-doped crystalline copper oxide (CuO:Mn) nano-platelets on human normal BJ fibroblasts and human A375 skin melanoma was assessed. The particles were synthesized at room temperature via the hydrothermal method. A complete physicochemical characterization of the materials was performed by employing various techniques including X-ray diffraction, electron microscopy, X-Ray photoelectron spectroscopy, and dynamic light scattering. Morphological investigations revealed a flat structure with nearly straight edges, with sizes spanning in the nanometer range. XRD analysis confirmed the formation of the CuO phase with good crystallinity, while XPS provided insights into the Mn doping. The findings indicate that nano-platelets interact with cells actively by mediating essential molecular processes. The exogenous manganese triggers increased MnSOD production in mitochondria, compensating ROS produced by external stress factors (Cu²⁺ ions), and mimics the endogenous SODs production, which compensates internal ROS production as it normally results from cell biochemistry. The effect is differentiated in normal cells compared to malignant cells and deserves investigation. Full article

Microbial resistance to conventional biocides is closely linked to the more complex problem of antibiotic resistance. Therefore, the development of novel and highly antimicrobial effective disinfectants is encouraged. Due to their broad spectrum of action and low toxicity, Argirium Silver Ultra Nano Clusters (Argirium SUNc^®), a new generation of silver nanoparticles, could be one of them. In this regard, the aim of the present work was to evaluate their biocidal properties in two different formulations against the hygiene indicator microorganisms potentially present in three different Italian food industries and to compare them with the chemical disinfectant most commonly used by operators for routine cleaning. Therefore, a series of microbiological swabs on different foodstuff contact surfaces were performed before and after the application of the solutions at each food company. The data showed that this novel nanomaterial was effective against all the parameters analyzed, being able to inhibit or reduce the growth of the tested microorganisms. Furthermore, in most cases, the two sanitizing solutions tested had a greater inhibitory power than the conventional disinfectant. For this reason, Argirium SUNc^® has great potential to be used in the near future as a new-generation disinfectant, an alternative to conventional disinfectants that promote the spread of antibiotic resistance. Full article

The disinfection of drinking water is essential for eliminating pathogens and preventing waterborne diseases. However, this process generates various disinfection byproducts (DBPs), which toxicological research indicates can have detrimental effects on living organisms. Moreover, the safety of these DBPs has not been sufficiently assessed, underscoring the need for a comprehensive evaluation of their toxic effects and associated health risks. Compared to traditional methods for studying the toxicity of pollutants, emerging electrochemical sensing technologies offer advantages such as simplicity, speed, and sensitivity, presenting an effective means for toxicity research on pollutants. However, challenges remain in this field, including the need to improve electrode sensitivity and reduce electrode costs. In this study, a pencil graphite electrode (PGE) was modified with carboxylated multi-walled carbon nanotubes (MWCNT-COOH) and nano-iron (III) oxide (α-Fe₂O₃) to fabricate a low-cost electrode with excellent electrocatalytic performance for cell-active substances. Subsequently, a novel cellular electrochemical sensor was constructed for the sensitive detection of the toxicity of three drinking water DBPs. The half inhibitory concentration (IC₅₀) values of 2-chlorophenylacetonitrile (2-CPAN), 3-chlorophenylacetonitrile (3-CPAN), and 4-chlorophenylacetonitrile (4-CPAN) for HepG2 cells were 660.69, 831.76, and 812.83 µM, respectively. This study provides technical support and scientific evidence for the toxicity detection and safety assessment of emerging contaminants. Full article

Among nanomaterials, silver nanoparticles (AgNPs) are cost-effective and exhibit unique physicochemical properties that enable them to become the most used agents for the manufacture of various products known as nano-enabled, including those for personal care, drugs, fabrics, sprays, disinfectants, vacuum cleaners, and air conditioners, with a continuous expansion to different sectors. Industrial discharges, the disposal of wastewater treatment effluents, and indirect runoff from the soil are some factors that are increasing the accumulation of AgNPs in aquatic and wetland ecosystems. Herewith, we critically analyze the progress in the research of the uptake and translocation of AgNPs in aquatic and wetland plants and their phytotoxic effect that depends on the concentration, size, distribution, morphological shape, surface characteristics and chemical composition of the nanoparticles, as well as the plant genotypes, among other factors. Due to biological plasticity, the toxicity level of AgNPs may vary among plant species, which may be further affected by the mode of application, time of exposure, and plant conditions (e.g., agronomic management, growth rate, phenological stage, etc.). Therefore, it is possible to identify and select competent plants for phytoremediation purposes, including superior capabilities for phytoextraction, phytofiltration, and phytostabilization. The review also identifies the main gaps that require attention in future research in order to elucidate a more integrative map aimed to reduce the potential threats to the environment and living organisms including humans. Full article

Cellulose in the nano regime, defined as nanocellulose, has been intensively used for water treatment. Nanocellulose can be produced in various forms, including colloidal, water redispersible powders, films, membranes, papers, hydrogels/aerogels, and three-dimensional (3D) objects. They were reported for the removal of water contaminants, e.g., heavy metals, dyes, drugs, pesticides, pharmaceuticals, microbial cells, and other pollutants from water systems. This review summarized the recent technologies for water treatment using nanocellulose-based materials. A scientometric analysis of the topic was also included. Cellulose-based materials enable the removal of water contaminants, and salts offer advanced technologies for water desalination. They are widely used as substrates, adsorbents, and catalysts. They were applied for pollutant removal via several methods such as adsorption, filtration, disinfection, coagulation/flocculation, chemical precipitation, sedimentation, filtration (e.g., ultrafiltration (UF), nanofiltration (NF)), electrofiltration (electrodialysis), ion-exchange, chelation, catalysis, and photocatalysis. Processing cellulose into commercial products enables the wide use of nanocellulose-based materials as adsorbents and catalysts. Full article

A series of quaternary ammonium or phosphonium salts were applied as zeolite growth modifiers in the synthesis of hierarchical ZSM-5 zeolite. The results showed that the use of methyltriphenylphosphonium bromide (MTBBP) could yield nano-sized hierarchical ZSM-5 zeolite with a “rice crust” morphology feature, which demonstrates a better catalytic performance than other disinfect candidates. It was confirmed that the addition of MTBBP did not cause discernable adverse effects on the microstructures or acidities of ZSM-5, but it led to the creation of abundant meso- to marco- pores as a result of aligned tiny particle aggregations. Moreover, the generation of the special morphology was believed to be a result of the coordination and competition between MTBBP and Na⁺ cations. The as-synthesized hierarchical zeolite was loaded with Zn and utilized in the propane aromatization reaction, which displayed a prolonged lifetime (1430 min vs. 290 min compared with conventional ZSM-5) and an enhanced total turnover number that is four folds of the traditional one, owing to the attenuated hydride transfer reaction and slow coking rate. This work provides a new method to alter the morphological properties of zeolites with low-cost disinfectants, which is of great potential for industrial applications. Full article

Adsorptive, catalytic, and antibacterial properties of clinoptilolite-rich tuffs (ZT) are presented here. ZT transformed into Fe-containing ZT (Fe-ZT) removes various organic and inorganic anions from water. Fe-ZT, which contains selenium, is beneficial for growing Pleurotus ostreatus mushrooms. The fungi convert inorganic Se from Fe-ZT into a more useful organically bonded form. ZT and Fe-ZT as supplements retain nitrogen and potassium in sandy, silty loam and silty clay soils. ZT shows an affinity toward toxic metal cations, which are essential for cleaning contaminated water. The adsorption of atenolol, acetylsalicylic, and salicylic acid onto M-ZT (M–Cu²⁺, Mn²⁺, Ni²⁺, or Zn²⁺) from water solutions suggests that both the natures of M and pharmaceuticals have a significant impact on the adsorption mechanism and determine the adsorption capability of the ZT. ZT is an excellent carrier for ultrafine (2–5 nm) nano oxide particles, which have been shown to have catalytic activity in different chemical processes and photodegradation reactions of organic pollutants. ZT can also be transformed into SO₄-SnO₂-ZT, which is catalytically active as a solid acid. M-ZT is an effective carrier of valuable bacteria. Ag-ZT possesses beneficial bactericidal activity in disinfecting water and soil remediation. Full article

The presence of high concentrations of geogenic arsenic (As) in groundwater poses a serious threat to the health of millions of individuals globally. This paper examines the research progress of groundwater with high concentrations of geogenic As through a comprehensive literature review and analysis, covering distribution, health risks, in situ remediation, regulatory technologies, and development trends, to establish a reference for future research. The global distribution of geogenic high-As groundwater is mainly in inland basins and river deltas of countries in South Asia, East Asia, and South America. High-As risk areas can be modeled using hydrogeologic data and field measurements. This modeling approach allows for assessing and measuring potential areas of high-As groundwater. In order to provide safe drinking water promptly and effectively to areas affected by high-As groundwater, in situ rapid detection and remediation techniques have been given significant attention. This paper introduces household- or community-scale As removal technologies, including flocculant–disinfectant, bucket treatment units, use of activated alumina, use of nano zero-valent iron, aquifer iron coating technology, and bioremediation, summarizing the basic mechanisms of arsenic removal for each technology. Guaranteeing the sustainability of site-scale remediation technologies, reasonable aquifer management, and exploring alternative water sources are crucial for combating high-As groundwater contamination. Future studies should aim to elucidate the mechanisms of As’s coexistence with other pollutants in groundwater, effectively treating As-containing wastes or sludge produced during the treatment process and exploring better treatment options. Full article

Quaternary ammonium surfactants, due to their diverse chemical structure and their biological properties, can be used in medicine as DNA carriers, disinfectants, and antimicrobial and antitumor agents. In this study, using melanoma A375, colon adenocarcinoma HT-29 and normal human dermal fibroblast (NHDF) cells, we tested the hypothesis that the quaternary ammonium surfactants 2-dodecanoyloxyethyl)trimethylammonium bromide (DMM-11), 2-dodecanoyloxypropyl)trimethylammonium bromide (DMPM-11) and 2-pentadecanoyloxymethyl)trimethylammonium bromide (DMGM-14) act selectively against cancer cells. The results showed that these compounds led to the initiation of the apoptotic process of programmed cell death, as evidenced by the ratio of the relative expression of Bax protein to Bcl-2. The encapsulation of surfactants in liposomes allowed lower concentrations to be used. Moreover, encapsulation reduced their toxicity towards non-cancerous cells. The anticancer efficiency and apoptotic effect of the liposomal formulations with surfactants (DMM-11, DMPM-11 and DMGM-14) were higher than those of surfactant-free liposomes. Therefore, quaternary ammonium surfactant-loaded liposomes show significant potential as delivery vehicles for the treatment of melanoma and colon cancers. The use of nano-formulations offers the advantage of optimizing quaternary ammonium surfactant delivery for improved anticancer therapy. Full article

Dual-frequency ultrasound (DFUS) coupled with sonocatalysts has emerged to be an advanced tool for antimicrobial applications in medicine but remains scarcely studied for water disinfection. In the present work, we first integrated high-frequency DFUS (120 + 1700 kHz), persulfate (S₂O₈²⁻) and ZnO nano- (50 nm) and microparticles (1 μm) for eradicating Escherichia coli and Enterococcus faecalis in synthetic water. For E. coli, the efficiency of DFUS-based processes can be ranked as follows: DFUS < DFUS/ZnO < DFUS/S₂O₈²⁻ < DFUS/ZnO/S₂O₈²⁻. A similar efficiency of the DFUS/S₂O₈²⁻ and DFUS/ZnO/S₂O₈²⁻ processes was found for more resistant E. faecalis. In the absence of persulfate, the performance of 1 μm ZnO was higher than that observed with 50 nm for inactivating E. coli via the DFUS/ZnO and 1700 kHz/ZnO processes. A synergy of DFUS in terms of 5-log (total) reduction was found in the S₂O₈²⁻/ZnO-based systems, being higher for E. faecalis (synergistic coefficient = 1.8–3.0). The synergistic effect was proposed to be driven by the boosted generation of reactive oxygen species and sonoporation. This study opens prospects for the development of novel DFUS-based piezo-catalytic systems for efficient water disinfection. Full article