Search Results (266)

Background: Biomedical device-associated infections pose major challenges in surgical care, particularly in hernia repair where polypropylene (PP) meshes and sutures are prone to bacterial colonization and biofilm formation. The limitations of antibiotic resistance and toxicity warrants the need of developing innovative antibacterial strategies. Methods: We developed a composite coating of hydroxypropyl methylcellulose (HPMC) and zinc oxide nanorods (ZnO NP) synthesized via thermal decomposition. This coating was applied to PP meshes and sutures to enhance anti-adhesive properties. The study evaluated surface hydrophilicity through water contact angles, estimation of Zn²⁺ ions using inductively coupled plasma–mass spectrometry (ICP-MS), and long-term efficacy over six months. Safety was assessed via systemic toxicity studies in murine models. Results: The ZnO NPs exhibited potent antibacterial efficacy, achieving up to 99.999% killing against Klebsiella pneumoniae. When applied as an HPMC-ZnO coating, PP meshes and sutures demonstrated enhanced hydrophilicity, reducing water contact angles by ~41° and facilitating prevention of bacterial adhesion. The coated meshes inhibited bacterial attachment by 83% (Escherichia coli), 60% (Pseudomonas aeruginosa), 99.6% (K. pneumoniae), and 99% (Staphylococcus aureus). Similarly, coated sutures reduced adhesion by 67–96% across these strains. Long-term storage studies showed retained antibiofilm efficacy for up to six months. In vivo assessments indicated negligible systemic toxicity of ZnO NPs in murine models. Conclusions: Collectively, these findings highlight HPMC-ZnO NPs coatings as a safe, durable, and effective strategy to functionalize PP-based meshes and sutures, reducing the risk of surgical site infections and demonstrating the potential for broader biomedical applications. Full article

Background: Surface contamination in healthcare environments plays a key role in the persistence and transmission of microorganisms. Long-lasting antimicrobial coatings based on copper–polymer complexes offer a promising passive strategy to minimize environmental contamination and healthcare-associated infections. Methods: This study evaluated a copper-alloy polymeric tape through physicochemical, in vitro, and hospital-based assessments. Structural analyses (XRD, Raman, SEM, EDX) were used to characterize the material, while antimicrobial efficacy was determined against Gram-positive and Gram-negative bacteria following ISO 22196:2011. A randomized 19-week clinical study was conducted in the Emergency and Urgent Unit of the University Hospital of Brasília to quantify microbial loads on high-touch surfaces covered with the copper-alloy tape or a non-antimicrobial control. Results: Structural characterization techniques validated the integrity and heterogeneous distribution of copper within the polymeric matrix. All tested bacterial strains exhibited complete growth inhibition on the copper-alloy tape, with final counts consistently below the detection threshold (<1.00 log10 CFU/mL). Human keratinocytes analyzed by SEM showed preserved morphology. In hospital conditions, treated surfaces maintained significantly lower microbial loads than controls over 19 weeks. The number of yeast-positive samples was small compared to the total number of samples collected during the study, but Candida parapsilosis was the most frequently identified species. Conclusions: These findings support its use as a sustainable intervention to reduce environmental contamination and infection risks in healthcare settings. Full article

Accurate detection of microbial contamination is essential in the assessment of toxicological and immunological responses to various materials, as low-level contaminants can lead to confounding results. Traditional endotoxin testing relies on the Limulus Amebocyte Lysate (LAL) assay, which depends on horseshoe crab blood and raises both ecological and ethical concerns. Sustainable alternatives such as recombinant Factor C (rFC) provide a promising solution, yet validation for the detection of endotoxin in nanomaterials remains incomplete. In this study, we have used rFC alongside Toll-like receptor (TLR) reporter assays to detect both endotoxin and broader microbial contaminants in 31 nanomaterials from diverse classes. Special attention was given to assay interference by nanomaterials to ensure reliable detection. The rFC assay demonstrated a sensitive detection limit of 0.005 EU/mL, equivalent to the LAL assay, and showed that more than 50% of tested nanomaterials contained low-level endotoxin contamination. Additionally, several nanomaterials activated the TLR2 reporter, indicative of microbial contaminants beyond endotoxin. These results suggest that rFC can serve as a sustainable and reliable replacement for LAL in nanomaterial endotoxin testing but also emphasize the limitations of relying solely on endotoxin-specific assays. We recommend that future nanotoxicological evaluations integrate rFC with complementary methods, such as TLR-based approaches, and include thorough interference controls to ensure robust and comprehensive microbial contamination assessment. Full article

Polyethylene terephthalate-derived fluorescent carbon quantum dots (PET-CQDs) are promising nanomaterials for sensing and biomedical uses, yet their biological interactions after metal doping require careful evaluation. Here, we report an in silico assessment of pristine and dual-site (via graphitic [G] and carbonyl [O]) metal-doped PET-CQDs (Ca, Mg, Fe, Zn) using molecular docking against eight human proteins: HSA (distribution), CYP3A4 (metabolism), hemoglobin (systemic biocompatibility), transferrin (uptake), GST (detoxification), ERα (endocrine regulation), IL-6 (inflammation), and caspase-3 (cytotoxic signaling) together with ADMET profiling and DFT–docking correlation analysis. Docking affinities were compared with controls and ranged from −7.8 to −10.4 kcal·mol⁻¹ across systems, with binding stabilized by π–π stacking, hydrogen bonding and metal–ligand coordination involving residues such as arginine, tyrosine and serine. Importantly, top-performing CQD variants differed by target: PET-CQDs, MgG_PET-CQDs and FeG_PET-CQDs were best for GST; ERα interacted favorably with all doped variants; IL-6 bound best to CaO_PET-CQDs and FeO_PET-CQDs (≈−7.1 kcal·mol⁻¹); HSA favored CaG_PET-CQDs (−10.0 kcal·mol⁻¹) and FeO_PET-CQDs (−9.9 kcal·mol⁻¹); CYP3A4 bound most strongly to pristine PET-CQDs; hemoglobin favored MgG_PET-CQDs (−9.6 kcal·mol⁻¹) and FeO_PET-CQDs (−9.3 kcal·mol⁻¹); transferrin favored FeG_PET-CQDs; caspase-3 showed favored binding overall (pristine −6.8 kcal·mol⁻¹; doped −7.4 to −7.6 kcal·mol⁻¹). ADMET predictions indicated high GI absorption, improved aqueous solubility for some dopants (~18.6 mg·mL⁻¹ for Ca-O/Mg-O), low skin permeability and no mutagenic/carcinogenic flags. Regression analysis showed frontier orbital descriptors (HOMO/LUMO) partially explain selective affinities for ERα and IL-6. These results support a target-guided selection of PET-CQDs for biomedical applications, and they call for experimental validation of selected dopant–target pairs. Full article

The widespread application of nanoparticles (NPs) in fields ranging from consumer products to industrial processes has led to increased concerns about their potential toxic effects on human health and the environment. While traditional toxicological studies often evaluate the effects of individual NPs, real-world exposure scenarios typically involve mixtures of NPs, where interactions between particles can significantly alter their toxicological profiles. This study provides an overview of overcoming this gap by possible utilization of high-throughput screening (HTS) for evaluation of the combined effects of NP mixtures under various exposure conditions. This review discusses HTS of metal oxide NPs, which have cytotoxic, genotoxic, and oxidative stress-inducing effects. Using HTS, this review describes multiple studies with multiple mixture ratios and exposure durations using human lung epithelial cells and zebrafish embryo systems. The review also describes a range of interactions, from synergistic effects, where the combined toxicity might be the sum of individual toxicities. Oxidative stress and metal ion release were key drivers of toxicity, particularly in metal oxide-dominant NP mixtures. This theoretical study highlights the importance of integrating HTS into nanotoxicology research to provide a more comprehensive understanding of the toxic behavior of NPs. Full article

Although numerous experimental studies have demonstrated the carcinogenic potential of multi-walled carbon nanotubes (MWCNTs) in lungs, the underlying molecular mechanisms—especially gene expression changes associated with different tumor types—remain poorly characterized. To elucidate the molecular signatures associated with MWCNT-induced carcinogenesis, we performed microarray-based gene expression profiling of rat lung tumors induced by MWCNT-7, including both adenocarcinoma (ADC) and malignant mesothelioma (MM), as well as ADCs induced by two types of double-walled CNTs (DWCNTs) differing in fiber length (1.5 µm and 7 µm). Hierarchical clustering revealed that the MWCNT-7-induced MM exhibited a gene expression profile distinct from the ADCs. The ADCs induced by the DWCNTs and the ADC induced by MWCNT-7 shared several pathways that were distinct from those of the MWCNT-7 induced MM. The distinct pathways upregulated in the ADCs versus the MM support the conclusion that MWCNT-induced ADCs arise through distinct biological mechanisms compared to MWCNT-induced MMs and identified tumor-type-specific biomarker candidates: complement factor I (CFI) and secreted phosphoprotein 1 (SPP1) for ADCs, and fibronectin 1 (FN1) for MM. In addition, the gene expression profiles of the ADCs induced by the three fiber types indicate that both types of thin flexible DWCNTs used in the present study promoted a number of carcinogenic pathways in the rat lung that were also promoted by MWCNT-7, which is a class 2B carcinogen. These results support the conclusion that DWCNTs are carcinogenic in the rat lung and highlight the importance of further assessments of the potential lung carcinogenicity of inhaled thin flexible CNTs. Full article

Graphene-based materials have been the subject of extensive scientific investigations owing to their distinctive properties and versatile functionalities. However, their applications are hindered due to limited material performance, difficulties in recycling, and high costs during manufacturing. Considering this, studies have developed graphene or its derivatives by combining it with other components, while some of these composites revealed significantly improved performance with lesser consumption of raw materials; the underlying mechanisms remain inadequately elucidated. Therefore, the aspiration for novel applications of graphene-based materials could be significantly improved with the full utilization of the synergistic effects of these materials. In this review, we intend to discuss the synergistic activities and their inherent mechanisms between graphene or its derivatives and metals, metal oxides, polymers, and bioactive compounds, among others. The effectiveness of synergisms in enhancing the performance of graphene-based composites is corroborated by studies in a variety of application areas such as antimicrobial materials, cancer therapy, sensors, electronic devices, catalysts, and more. The content presented will be useful to guide the future development of graphene-based materials that are highly efficient and environmentally friendly. Full article

Quantum dots (QDs) possess unique optical and electronic properties, enabling wide applications in biomedicine and optoelectronics, but their nanoscale size and surface chemistry could pose potential toxicity risks. This study established a systematic, multi-endpoint framework for QD toxicity assessment. Physicochemical properties of various QDs and their multiple toxicity endpoints, including cell death, inflammation, and oxidative stress, were collected to build machine learning models (RF, XGBoost, KNN, SVM). The predictive toxic effects were then validated based on the brain organoid. Shapley Additive exPlanations (SHAP) analysis revealed that exposure dose and particle size were key cross-model drivers, while zeta potential and optical properties differentially affected specific toxicity endpoints. Integration of GEO-derived differentially expressed genes with protein–protein interaction networks and molecular docking showed that the proteasome inhibitor Carfilzomib is an efficient interventive drug because of its strongest binding to core targets. In this study, the framework of prediction, validation and intervention effectively evaluated multi-endpoint QD toxicity and provided a systematic approach for safety assessments and strategy developments of nanomaterials. Full article

This brief review examines the application of various computational approaches to investigate the physicochemical and interfacial properties of nanocomposite systems. Density functional theory (DFT), a quantum-mechanical technique, examines the fundamental properties of nanomaterials. Molecular docking studies have also been explored to show how different biological macromolecules can interact and bind with the nanoparticles (NPs’) surface, along with the molecular dynamics (MDs) simulations, which further strengthen the docking findings. Furthermore, nanotoxicology, a comparatively less explored field, has also been introduced, providing an insight into the interactions between nanomaterials and the environment and biological systems, including the harmful consequences. Full article

Nanomaterials (NMs) possess unique physicochemical features that set them apart from bulk counterparts. Their adjustable properties provide remarkable flexibility, giving rise to a wide array of variants. However, these attributes can also trigger complex biological interactions, particularly the generation of reactive oxygen species (ROS), which are central to nanomaterial-induced cytotoxicity. The ambivalent nature of ROS, essential for physiological signaling yet harmful when dysregulated, can lead to substantial health consequences. The scarcity of reliable toxicity and safety data, together with the inadequacies of conventional testing methods, highlights the urgent need for more effective strategies to assess nanomaterial-related hazards and risks. Given the intricate interplay between NMs and biological systems, computational approaches, particularly machine learning (ML), have emerged as powerful tools to model ROS dynamics, predict cytotoxic outcomes, and optimize nanomaterial design. This review highlights recent advances in applying ML to predict both the generation and neutralization of ROS by diverse NMs and to identify the critical determinants underlying ROS-mediated toxicity. These insights provide new opportunities for predictive nanotoxicology and the development of safer, application-tailored NMs. Full article

Background: Engineered nanoparticles (NPs)—titanium dioxide, silver, zinc oxide and silica—are widely used in cosmetics for UV protection, antimicrobial activity and texturising effects. Chronic consumer-level exposure may impair skin-barrier integrity, disturb microbiome composition and dysregulate immune signalling via the gut–skin axis. Current regulatory frameworks typically omit chronic- or microbiome-focused safety assessments, leaving potential gaps. Objectives: This study aimed to evaluate the long-term effects of cosmetic-relevant NPs (titanium dioxide, silver, zinc oxide, silica) on skin and gut microbiota, epithelial-barrier integrity and immune signalling—including telocyte- and exosome-mediated pathways—and to identify regulatory shortcomings, particularly the absence of microbiome endpoints, validated chronic models and consideration of vulnerable populations. Methods: Following PRISMA 2020, PubMed, Scopus and Web of Science were searched for English-language in vivo animal or human studies (December 2014–April 2025) meeting chronic-exposure criteria (≥90 days in rodents or >10% of lifespan in other species; for humans, prolonged, repetitive application over months to years consistent with cosmetic use). Although not registered in PROSPERO, the review adhered to a pre-specified protocol. Two independent reviewers screened studies; risk of bias was assessed using a modified SYRCLE tool (animal) or adapted NIH guidance (zebrafish). Owing to heterogeneity, findings were synthesised narratively. Results: Of 600 records, 450 unique articles were screened, 50 full texts were assessed and 12 studies were included. Oral exposure predominated and was associated with dysbiosis, barrier impairment, immune modulation and metabolic effects. Dermal models showed outcomes from minimal change to pronounced immune activation, contingent on host susceptibility. Comparative human–animal findings are summarised; telocyte and exosome pathways were largely unexplored. Regulatory reviews (EU SCCS, US FDA and selected Asian frameworks) revealed no requirements for chronic microbiome endpoints. Limitations: Evidence is limited by the small number of eligible studies, heterogeneity in NP characteristics and exposure routes, predominance of animal models and a scarcity of longitudinal human data. Conclusions: Cosmetic nanoparticles may disrupt the microbiome, compromise barrier integrity and trigger immune dysregulation—risks amplified in vulnerable users. Existing regulations lack requirements for chronic exposure, microbiome endpoints and testing in vulnerable groups, and neglect mechanistic pathways involving telocytes and exosomes. Long-term, real-world exposure studies integrating gut–skin microbiome and immune outcomes, and harmonised global nanomaterial-safety standards, are needed to ensure safer cosmetic innovation. Full article

In a changing world where temperature is expected to increase, emerging nanopollutants could affect the biota in complex ways. With zinc oxide nanoparticles (ZnONP) being one of the most applied nanomaterials, we exposed the freshwater invasive bivalve Limnoperna fortunei to 0 (control), 25, and 250 µg/L of ZnONP at 27 or 31 °C for 96 h. In parallel, a 24 h bioassay was performed to calculate filtration rate. After 96 h, in soft tissue of the bivalves, tissue-damage-related enzyme activities (aspartate aminotransferase and alkaline phosphatase) were inhibited at both concentrations and temperatures. Oxidative stress was observed through increased superoxide dismutase activity after both ZnONP concentrations at 27 °C and decreased catalase activity after 250 µg/L at 31 °C, while glutathione-S-transferase activity showed opposing significant tendencies depending on temperature. After 6 h, the filtration rate differed significantly between control groups, as it was higher at 31 °C. However, in case of 31 °C, bivalves exposed to ZnONP drastically decreased their filtration rate compared to control. Our study highlights nanotoxicological implications of ZnONP; as even at environmentally relevant concentrations (such as the lowest applied in this study), they exert deleterious effects on freshwater organisms, which could be worsened in a climate-change scenario. Full article

We previously carried out an in vivo 2-year study to assess the potential toxicity/carcinogenicity of double-walled carbon nanotubes (DWCNTs) in a rat lung. We found that administration of DWCNTs by intratracheal–intrapulmonary spraying (TIPS) at a dose of 0.5 mg/rat induced the development of lung tumors in 7 of 24 treated rats while 1 of 21 untreated rats and 1 of 25 vehicle treated rats developed lung tumors. In the current study, we administered DWCNTs of different lengths, 1.5 µm, 7 µm, and 15 µm, to rats by TIPS to investigate the possible effect of the length of this thin, flexible CNT on toxicity/carcinogenicity in rat lungs. Rats were administered DWCNTs with lengths of 1.5 µm (D1.5), 7 µm (D7), and 15 µm (D15) by TIPS once every other day over the course of two weeks for a total of eight administrations. The total dose administered was approximately 22 × 10¹² fibers per rat, corresponding to 0.0504 mg for D1.5, 0.232 mg for D7, and 0.504 mg for D15. Another group of rats was administered 0.5 mg MWCNT-7, a known carcinogen. Animals were killed at weeks 6 and 104 (4 and 102 weeks after the final TIPS administration). The mean survival time of the rats in the untreated, vehicle, D1.5, D7, and D15 groups was 99 to 104 weeks. One rat in the D1.5 group and one rat in the D15 group died before week 75. The remaining rats in the untreated, vehicle, D1.5, D7, and D15 groups were included in the final assessment of lung toxicity/carcinogenicity. In contrast, 11 rats in the MWCNT-7 group died before week 75 due to the development of malignant mesothelioma. Due to the much shorter survival time of the rats treated with MWCNT-7, accurate assessment of lung proliferative lesions in this group was not possible. At week 6, an increase in alveolar macrophages and granulation tissue foci in the alveoli was observed in all DWCNT administered groups. The alveolar epithelial cell PCNA index was also significantly increased in the D7 and D15 groups. Increases in alveolar macrophages, granulation tissue foci, and the alveolar epithelial cell PCNA index were observed in all DWCNT-treated groups at the final sacrifice. The incidences of lung tumors were 0/13, 0/12, 4/12, 3/8, and 2/10 in the untreated, vehicle, D1.5, D7, and D15 groups, respectively. In agreement with our previous study, the DWCNTs tested in the present study were carcinogenic in the rat lung. In addition, we present evidence that DWCNT fiber length may possibly have an effect on DWCNT-induced carcinogenicity in rat lungs. Full article

Cationic polyamine-based carbon dots (CDs) are increasingly being explored for biomedical applications. These ultrasmall (<10 nm) fluorescent nanoparticles, synthesized from organic precursors and functionalized with polyamines, possess a strong positive surface charge that enables efficient complexation and delivery of nucleic acids, making them promising candidates for gene therapy. However, the mechanisms by which the immune system, particularly macrophages, recognizes and responds to these nanomaterials remain poorly understood. In this study, we investigated the role of surface receptors in the uptake and biological effects of cationic polyamine-based CDs in macrophages. Our data showed that Fc receptors and the Toll-like receptor 4 (TLR4) were minimally involved in CD internalization and associated cellular responses in contrast to scavenger receptors (SRs). Indeed, SR inhibition reduced CD-induced cell viability loss, LDH release, and secretion of the pro-inflammatory cytokine IL-1β. Among SRs, SR-A1 was identified as a key receptor mediating CD recognition and toxicity, likely through activation of the MERTK signaling pathway. Importantly, these mechanisms occurred in the absence of serum, indicating that protein corona formation is not required for CD interaction with macrophage surface receptors. Overall, our findings highlight the prominent role of SRs, particularly SR-A1, as receptors recognizing cationic polyamine-based CDs on the surface of macrophages, and provide new insights into the cellular mechanisms underlying the immunotoxicity of these carbon-based nanomaterials. Full article

Nanoplastics (NPs), an emerging class of environmental pollutants, are increasingly recognized for their potential to interfere with critical cellular processes. Autophagy, a conserved degradative pathway essential for maintaining cellular homeostasis and adaptation to stress, has recently become a focal point of nanotoxicology research. This review synthesizes current evidence on the interactions between NPs and autophagic pathways across diverse biological systems. Findings indicate that NPs can trigger autophagy as an early cellular response; however, prolonged exposure may lead to autophagic dysfunction, contributing to impaired cell viability and disrupted signaling. Particular attention is given to the physiochemical properties of NPs such as size, surface charge, and polymer type, which influence cellular uptake and intracellular trafficking. We also highlight key mechanistic pathways, including oxidative stress and mTOR modulation. Notably, most available studies focus almost exclusively on polystyrene (PS)-based NPs, with limited data on other types of polymers, and several reports lack comprehensive assessment of autophagic flux or downstream effects. In conclusion, a better understanding of NP–autophagy crosstalk—particularly beyond PS—is crucial to evaluate the real toxic potential of NPs and guide future research in human health and nanotechnology. Full article