Search Results (1,704)

Copper-based nanoparticles (as Cu₂O) are a key component in marine antifouling paints and, as coatings degrade, release nanoparticles that can affect a wide range of non-target organisms. This study investigates the impact of Cu₂O nanoparticles on the early development of urchins Arbacia lixula, Paracentrotus lividus and Sphaerechinus granularis, and benchmarks their toxicity against similarly sized Cu and CuO nanoparticles and ionic copper. Concentration-dependent toxicity was noted for all forms of copper at concentrations in the 1 to 5000 µg L⁻¹ range. EC₅₀ values after Cu₂O exposure indicated that A. lixula (99 µg L⁻¹) was generally more sensitive than the other two species, with EC₅₀ values of 371 µg L⁻¹ and 606 µg L⁻¹ noted for S. granularis and P. lividus, respectively. The same trend across species was noted for both Cu and CuO, although these nanoparticles generally showed higher EC₅₀ values, indicating lower toxicity compared to Cu₂O. LC₅₀ values qualitatively parallel the corresponding EC₅₀ values, with Cu₂O consistently the most toxic, while Cu was less harmful, and CuO did not reach LC₅₀ at any concentration. Again, greatest lethality was noted in A. lixula. While copper ion release from Cu was much greater than from CuO and Cu₂O, the latter showed similar or greater toxicity to developing embryos compared to Cu. This indicates that copper ions are not the sole driver of toxicity of Cu₂O, but there may also be a contribution derived from Cu₂O redox activity within cells or at membranes that negatively impact oxidative stress defence mechanisms and metabolic pathways. Full article

Background: To enhance the bioavailability and neuroprotective efficacy of biatractylolide against Alzheimer’s disease by developing a novel Tween-80-modified pullulan–chenodeoxycholic acid nanoparticle as a delivery vehicle. Methods: Chenodeoxycholic acid (CDCA) was chemically conjugated to pullulan to yield hydrophobically modified pullulan (PUC), onto which polysorbate 80 (Tween-80) was subsequently adsorbed. The PUC polymers with CDCA substitution levels were analyzed by ¹H NMR spectroscopy. Nanoparticles were fabricated via the dialysis method and characterized by transmission electron microscopy and dynamic light scattering for morphology, size, and surface charge. In vitro neuroprotection was assessed by exposing SH-SY5Y and PC12 cells to 20 µM Aβ_25-35 to induce cytotoxicity, followed by pretreatment with biatractylolide-loaded PUC (BD-PUC) nanoparticle solutions at various biatractylolide concentrations. The in vivo brain-targeting capability of both empty PUC and BD-PUC particles was evaluated using a live imaging system. Results: The ¹H NMR analysis confirmed three distinct CDCA substitution degrees (8.97%, 10.66%, 13.92%). Transmission electron microscopy revealed uniformly dispersed, spherical nanoparticles. Dynamic light scattering measurements showed a hydrodynamic diameter of ~200 nm and a negative zeta potential. Exposure to 20 µM Aβ_25-35 significantly reduced SH-SY5Y and PC12 cell viability; pretreatment with BD-PUC nanoparticles markedly enhanced cell survival rates and preserved cellular morphology compared to cells treated with free biatractylolide. Notably, the cytoprotective effect of BD-PUC exceeded that of the free drug. In vivo imaging demonstrated that both empty PUC and Tween-80-adsorbed BD-PUC nanoparticles effectively accumulated in the brain. Conclusions: The protective effect of BD-PUC on SH-SY5Y and PC12 cells induced by Aβ_25-35 was higher than free biatractylolide solution, and the BD-PUC nanosolution modified with Tween-80 showed a brain-targeting effect. Full article

Microplastics (MPs), emerging contaminants of significant global concern, have a substantially increased environmental impact due to their biological persistence and accumulation in the body. Exposure to MPs has been associated with oxidative stress, systemic inflammation, and cellular dysfunction, notably affecting critical tissues such as the stomach, colon, and brain. This review explores the correlation between MPs and cancer risk along the gastric–colon–brain axis, identifying the signaling pathways altered by MP exposure. Furthermore, it highlights the role of functional nutrition and bioactive flavonoids—including chlorogenic acid, coumaric acid, and naringin—as well as the use of highly bioavailable combined polyphenol nanoparticles as potential detoxifying agents. Functional nutrients are effective in enhancing cellular resilience against reactive oxygen species (ROS) production and MP-induced toxicity, offering protective effects at the gastric, intestinal, and brain barriers. Activation of the Nrf2 pathway by bioactive compounds promotes the expression of detoxifying enzymes, suggesting a promising nutritional strategy to mitigate MP-related damage. This review underscores how functional nutrition may represent a viable therapeutic approach to reduce the harmful effects of MP exposure. The integration of advanced technologies—such as microfluidic systems, organ-on-a-chip platforms, and machine learning—and the identification of key molecular targets lay the foundation for developing preventive and personalized medicine strategies aimed at lowering the risk of environmentally induced carcinogenesis. Full article

Background/Objectives: The limited permeability of the blood–brain barrier (BBB) to biotherapeutics is a major challenge in the treatment of brain tumors. The nose-to-brain (N2B) delivery approach, which bypasses the BBB, offers a promising alternative way to treat these tumors. The aim of this work was to develop PLGA nanoparticles for N2B delivery of biodrugs using trastuzumab (TZB) as a paradigm. Methods: An in vitro model was used to evaluate the ability of PLGA nanoparticles to enhance passage through the nasal epithelium. We also compared the passage of loaded TZB versus unencapsulated TZB across an in vitro BBB model simulating systemic administration of TZB. TZB-loaded PLGA nanoparticles (NP-TZBs) were prepared using a double emulsion method followed by solvent evaporation and characterized for various properties, including particle size, polydispersity index, zeta potential, morphology, encapsulation efficiency, and drug loading capacity and release kinetics. TZB functionality was assessed after release from NP or passage through an in vitro barrier model. The permeability of TZB and NP-TZBs through in vitro models of nasal epithelium and BBB was investigated. Results: NP-TZBs exhibited an average size of about 200 nm with a polydispersity index of less than 20%, neutral charge, and a loading efficiency of 67%. Transmission electron microscopy revealed spherical nanoparticles with a smooth surface. Importantly, the TZB released from the nanoparticles retained all of its physicochemical properties and functionality. We observed that the NP-TZB formulation results in at least a nine-fold increase in TZB permeability across the nasal epithelium 24 h post-exposure, depending on the exposure conditions, but shows no significant improvement across the BBB model. The TZB released in the basal compartment is fully functional and able to recognize HER2 expressed on the surface of breast tumor BT474 cells. Conclusions: Using compounds already validated for clinical use, we were able to develop a formulation that allowed efficient passage of TZB across an in vitro nasal epithelial model. In contrast, no passage was observed across the BBB, supporting the notion of the superiority of the nose–brain route over systemic injection for in vivo delivery of TZB to the central nervous system. Full article

Herein, a facile strategy was proposed to enhance the gas sensing performance of SnO₂ for H₂ by regulating its crystalline phase composition. Sn-based metal–organic framework (Sn-MOF) precursors with different morphologies were synthesized by introducing the surfactant cetyltrimethylammonium bromide (CTAB). Upon calcination, these precursors yielded either mixed-phase (orthorhombic and tetragonal, SnO₂-C) or single-phase (pure tetragonal, SnO₂-NC) SnO₂ nanoparticles. Structural characterization and gas sensing tests revealed that SnO₂-C exhibited a high response of 7.73 to 100 ppm H₂ at 280 °C, more than twice that of SnO₂-NC (3.75). Moreover, SnO₂-C demonstrated a faster response/recovery time (10/56 s), high selectivity, a ppb-level detection limit (~79 ppb), and excellent long-term stability. Notably, although the addition of CTAB reduced the specific surface area of SnO₂, the resulting lower surface area minimized oxygen exposure during calcination, facilitating the formation of a mixed-phase heterostructure. In addition, the calcination atmosphere of SnO₂-C (flowing air or Ar) was adjusted to further investigate the role of the crystal phase in gas sensing performance. The results clearly demonstrated that mixed-phase SnO₂ exhibited superior sensing performance, achieving a higher sensitivity and a faster response to H₂. These findings underscored the critical role of crystal phase engineering in the design of high-performance gas sensing materials. Full article

Background: Healthcare-associated infections (HAIs) significantly increase morbidity, mortality, and healthcare costs. Among HAIs, catheter-associated infections are particularly prevalent due to the susceptibility of catheters to microbial contamination and biofilm formation, especially with prolonged use. Biofilms act as infection reservoirs, complicating treatment and often requiring catheter removal, thus extending hospital stays and increasing costs. Recent technological advances in catheter design have focused on integrating antifouling and antimicrobial coatings to mitigate or prevent biofilm formation. Methods: We developed COPESIL^®, a novel silicone rubber embedded with PEGylated copper nanoparticles designed to reduce microbial contamination on catheter surfaces. We conducted in vitro assays to evaluate the antimicrobial and antibiofilm efficacy of COPESIL^® against pathogens commonly implicated in catheter-associated urinary tract infections. Additionally, the safety profile of the material was assessed through cytotoxicity evaluations using HepG2 cells. Results: COPESIL^® demonstrated substantial antimicrobial activity, reducing contamination with Escherichia coli and Klebsiella pneumoniae by >99.9% and between 93.2% and 99.8%, respectively. Biofilm formation was reduced by 5.2- to 7.9-fold for E. coli and 2.7- to 2.8-fold for K. pneumoniae compared to controls. Cytotoxicity assays suggest the material is non-toxic, with cell viability remaining above 95% after 24 h of exposure. Conclusions: The integration of PEGylated copper nanoparticles into a silicone matrix in COPESIL^® represents a promising strategy to enhance the antimicrobial properties of catheters. Future studies should rigorously evaluate the long-term antimicrobial efficacy and clinical safety of COPESIL^®-coated catheters, with a focus on their impact on patient outcomes and infection rates in clinical settings. Full article

Epoxy polymers modified with nanoparticles are increasingly employed due to their enhanced performance in aggressive environments, characterized by mechanical stress, radiation exposure, and extreme temperatures. The mechanical failure of these polymers is attributed to the fracturing of atomic and molecular bonds, that subsequently excites electrons having the capability to be emitted from the nanolayer of the material. The present study demonstrates that the relationship between mechanical loading and electron emission over time serves as an indicator of surface loading and durability. By utilizing the Kinetic Nature of Solid Material Strength (KSMS) theory alongside near-threshold electron emission measurements, the article presents the behavior of epoxy polymers modified with SiO₂ nanoparticles under tensile loading. The results indicate that as mechanical load is applied, photoelectron emission (PE) pulses emerge. Notably, the pulse spectrum highest frequency (fmax) correlates with the time of atomic fluctuations (τ), defined by τ = 1/fmax. Furthermore, ultraviolet (UV) irradiation of the nanoparticles prior to mixing with the polymer is shown to influence the parameter of KSMS responsible for local stress concentration. This suggests that PE is connected with the homogeneity of the composite too. The achieved results demonstrate that PE contactless measurements can be used to detect mechanical destruction of the epoxy polymer composite surface nanolayer, as well as to assess its durability and corresponding activation energy. The results presented in the article may contribute to the development of more reliable epoxy polymer composites and durability measurements of their mechanically loaded surface layer or nanofilms. Full article

A straightforward and economical engraving diode laser with a 455 $\pm$$5$ nm visible wavelength was employed for the first time in a pulsed laser fragmentation in liquid (PLFL) technique coupled simultaneously with a chemical reduction method to synthesize silver nanoparticles (AgNPs) in an Origanum majorana extract liquid, as a natural reduction agent. The chemical reduction correlated with the PLFL method to control the NP size by examining the effect of irradiation times. The AgNPs were characterized by X-Ray diffraction (XRD), UV–vis spectrophotometry, dynamic light scattering (DLS), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy. The lattice diffraction Bragg’s planes (111), (200), (220), (311), and (222) were found by XRD. The AgNPs had a surface plasmon resonance (SPR) peak at around 432–409 nm. The position of this SPR peak moves toward shorter wavelengths, by around 23 nm, with increased laser irradiation. When exposure times were increased, a drop in Ag NP size was revealed, from 22 nm when only a chemical reduction approach was used to 12 nm when the PLFL technique was associated. The DLS and TEM confirmed the UV–vis results. Such consideration suggests that combining the chemical reduction and PLFL methods could enable the tuning of the Ag NP size to be tailored for specific applications. This work could open the field for synthesizing NPs and controlling their size using an easy and handy engraving laser. Full article

Several scientific studies have reported the opposing effects of silver nanoparticles (AgNPs) on angiogenesis, ranging from proangiogenic to anti-angiogenic. The widespread use of AgNPs in biomedical applications and the variability of their effects depending on concentration and exposure conditions highlight the need for further research into their impact on vascularization and endothelial cell behavior. This study aimed to investigate the potential influence of AgNPs on human umbilical vein endothelial cells (HUVECs) using a model incorporating a thin layer of an extracellular matrix (ECM). To this end, cytotoxicity was assessed, and endogenous nitric oxide and superoxide levels were measured. Additionally, the effects of AgNPs on HUVEC confluence and migration were evaluated. The expression levels of 43 proteins involved in angiogenesis were also analyzed. The results revealed that ECM enriched with AgNPs at a concentration of 0.5 mg/L enhanced cell coverage, promoted migration, and supported monolayer formation without inducing cytotoxicity. Full article

The advancement of optical materials has garnered significant interest from the global scientific community in the pursuit of efficient photocatalysts for the purification of water using light. This challenge, which cannot be addressed using traditional methods, is tackled in the present study utilizing unconventional approaches. This study presents the fabrication of an effective photocatalyst using an unconventional approach that employs explosive reactions. This method successfully produces 3D nanostructures composed of carbon nanotubes (CNTs), carbon nanofibers (CNFs), and silica–alumina nanoparticles at temperatures below 270 °C. Gold-supported silica–alumina–CNT–CNF nanostructures were synthesized and characterized using XRD, TEM, SEM, and EDX, in addition to mapping images. To study and determine the photoactivity of these produced nanostructures, two well-known photocatalysts—titanium dioxide and zinc oxide—were synthesized at the nanoscale for comparison. The results showed that the presence of CNTs and CNFs significantly reduced the band gap energy from 5.5 eV to 1.65 eV and 3.65 eV, respectively, after modifying the silica–alumina structure. In addition, complete degradation of green dye was achieved after 35 min of light exposure using the modified silica–alumina structure. Additionally, the surface properties of the modified silica–alumina had a positive role in accelerating the photocatalytic decomposition of the green dye NGB. A kinetic study confirmed that the modified silica–alumina functions as a promising additive for optical applications, accelerating the photocatalytic degradation of NGB to a rate three times faster than that of the prepared titanium dioxide and six times that of the prepared zinc oxide. Full article

The escalating challenge of antibacterial resistance has driven the widespread use of silver nanoparticles (AgNPs) due to their potent antimicrobial properties. AgNPs can be synthesised through diverse methods, spanning conventional chemical and physical routes to the increasingly favoured biosynthesis approach. While offering environmental advantages, the ecological impact of biogenically synthesized AgNPs, especially on aquatic ecosystems, requires thorough evaluation. The renal system, critical for maintaining physiological homeostasis via nephron-mediated waste removal, fluid regulation, and electrolyte balance, is highly vulnerable to toxicant-induced damage, which can negatively affect organismal fitness. This study aimed to assess the nephrotoxic effects of AgNPs, synthesized using entirely “green” methods, on zebrafish after 96-h exposures to three distinct concentrations alongside a control group. Acridine orange fluorescence microscopy revealed dose-dependent histopathological alterations in renal tissues. Specifically, at 0.031 μg/L and 0.250 μg/L, significant changes were observed, including glomerular shrinkage, proliferation of hematopoietic tissue, dissociation and dilation of renal tubules, and melanomacrophage aggregation. At 5.000 μg/L, prolonged exposure beyond 48 h indicated a potential for renal tissue cell renewal, suggesting a possible compensatory response. These results demonstrate the sensitivity of zebrafish kidneys to AgNPs and emphasize the imperative for comprehensive in vivo toxicity testing, irrespective of synthesis method, to accurately evaluate the potential for adverse ecological impacts and ensure the preservation of aquatic ecosystem integrity. Full article

One of the most urgent threats to public health worldwide is the ongoing rise of multidrug-resistant (MDR) bacterial strains. Among the most critical pathogens are MDR-Klebsiella pneumoniae strains. The lack of new antibiotics has led to an increased need for non-antibiotic antimicrobial therapies. Photodynamic therapy (PDT) has become increasingly significant in treating MDR bacteria. PDT uses photosensitizer compounds (PS) that generate reactive oxygen species (ROS) when activated by light. These ROS produce localized oxidative stress, damaging the bacterial envelope. A downside of PDT is the limited bioavailability of PSs in vivo, which can be enhanced by conjugating them with carriers like nanoparticles (NPs). Zinc nanoparticles possess antibacterial properties, decreasing the adherence and viability of microorganisms on surfaces. The additive or synergistic effect of the combined NP-PS could improve phototherapeutic action. Therefore, this study evaluated the effectiveness of the copper(I)-based PS CuC1 compound in combination with Zinc Oxide NP, ZnONP, to inhibit the growth of both MDR and sensitive K. pneumoniae strains. The reduction in bacterial viability after exposure to a PS/NP mixture activated by 61.2 J/cm² of blue light photodynamic treatment was assessed. The optimal PS/NP ratio was determined at 2 µg/mL of CuC1 combined with 64 µg/mL of ZnONP as the minimum effective concentration (MEC). The bacterial gene response aligned with a mechanism of photooxidative stress induced by the treatment, which damages the bacterial cell envelope. Additionally, we found that the PS/NP mixture is not harmful to mammalian cells, such as Hep-G2 and HEK-293. In conclusion, the CuC1/ZnONP combination could effectively aid in enhancing the antimicrobial treatment of infections caused by MDR bacteria. Full article

Background/Objectives: Engineered nanomaterials, particularly silver nanoparticles (AgNPs), have emerged as promising tools in oncology due to their ability to enhance tumor targeting and minimize off-target effects. This study investigates the cytotoxic effects of two different types of AgNPs—citrate-coated (AgNPs-cit) and EG₆OH-coated (AgNPs-EG₆OH)—on colorectal cancer (CRC) cell lines and healthy colonocytes, aiming to assess their potential as selective therapeutic agents. Methods: AgNPs-cit and AgNPs-EG₆OH were synthesized and characterized for size and surface properties. LoVo (microsatellite instability-high) and HT-29 (microsatellite stable) CRC cell lines, along with primary colonocyte cultures from healthy mucosal tissues, were exposed to these nanoparticles. Cytotoxicity was assessed through MTT assays, while morphological changes were observed using fluorescence microscopy. Internalization of the nanoparticles was evaluated by confocal microscopy. Results: AgNPs-cit exhibited significant cytotoxicity in LoVo cells, reducing viability and inducing morphological changes indicative of programmed cell death, especially after 48 h of exposure. In contrast, AgNPs-EG₆OH showed minimal effects on LoVo cells and no significant toxicity on HT-29 cells or primary colonocytes. Confocal microscopy confirmed nanoparticle internalization, with surface functionalization influencing the distribution patterns within cells. Conclusions: This study demonstrates that surface functionalization significantly influences the cytotoxicity of AgNPs, with citrate-coated nanoparticles showing selective effects on microsatellite instability-high CRC cells. These findings underscore the potential of surface-modified nanoparticles for targeted cancer therapy and highlight the importance of tailoring nanoparticle design to optimize therapeutic efficacy while minimizing off-target effects. Full article

This study reports the synthesis of aluminum-doped ZnO nanoparticles (Al-ZnO NPs) via a top-down mechanochemical solid-state reaction (SSR) approach using high-energy ball milling (HEBM) as a rapid, controllable, and efficient method. Al-ZnO samples were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and UV-Vis diffuse reflectance spectroscopy. Significantly, the band gap decreased by 0.215 eV when transitioning from pure ZnO to 9 wt.% Al-doped ZnO (Al-ZnO9). TEM analysis showed that after 4 h of milling at 1000 rpm, the particle size was reduced to 59 nm, exhibiting a spherical morphology crucial for enhanced bioactivity. The antimicrobial properties of the Al-ZnO NPs were evaluated using the well diffusion method against various pathogenic microorganisms, with a particular focus on Staph. aureus ATCC 29213 and Staph. epidermidis ATCC 12228, given their clinical significance as common pathogens in infections related to medical implants and prosthetics. Al-ZnO9 demonstrated superior antibacterial performance, producing inhibition zones of 13 mm and 15 mm against Staph. aureus and Staph. epidermidis, respectively. Moreover, exposure to visible light further amplified the antimicrobial activity. This research underscores the potential for the scalable production of Al-ZnO NPs, presenting a promising solution for addressing infections linked to implanted medical devices. Full article

Perfluoroalkyl substances (PFAS), also known as “forever chemicals”, are a class of highly stable chemical compounds that slowly contaminate waterbodies and soil. The widespread presence of PFAS is associated with adverse human health effects and is a major environmental concern. The conventional, highly sensitive methods used for PFAS detection are LC-MS/MS and solid phase extraction, but they are very complex and expensive. Therefore, there is an urgent need for sensitive, low-cost, and fast methods for the detection and removal of PFAS compounds from water and soil resources. The advancement of nanotechnology has significantly impacted advanced disease diagnosis and treatment in the last few decades. Currently, these engineered nanomaterials (ENMs) have been exploited for the development of advanced nano-enabled techniques for the detection and removal of environmental pollutants. Nano-enabled techniques also offer improved performance over conventional methods. In this review, the details of the detection and removal of PFAS, as well as their optimization and limitations, and future perspectives are discussed. We focused on the implementation of nanomaterials such as nanoparticles, nanotubes, nanorods, and nano*filtration membranes for efficient PFAS detection and removal. We also included the recent literature and global guidelines for PFAS use and the effect of PFAS exposure on human health. Full article