Engineered Nanomaterials Research Articles

Engineered nanomaterials (ENMs), particularly nano-titanium dioxide (nano-TiO2), are widely used across industries in Singapore, raising concerns about potential worker exposure. This study aimed to quantify occupational exposures and emissions at workplaces handling nano-TiO2, assessing work practices, usage patterns and workplace controls. Occupational exposure to nano-TiO2 was assessed across 7 workplaces (laboratories, manufacturing, downstream application, and recycling). Methods for characterizing personal exposure included personal gravimetric sampling (NIOSH 0600), elemental analysis (NIOSH 7300), and scanning electron microscopy (SEM), while real-time particle number concentration (PNC) monitoring was done to understand the particle distribution in the workplace environment during the tasks performed. Workplace observations included measurement of dimensions of the work area, existing control measures (engineering, administrative, and personal protective equipment), nature of nano-TiO2 handling practices, forms, quantities, particle size, and state changes of the nano-TiO2 used. Personal exposure samples were collected from 30 workers across workplaces. These include: 7 in laboratory, 10 in manufacturing, 6 in spraying, and 7 in shredding/recycling. Of these, 3 samples, collected during bulk loading and spraying activities, exceeded the NIOSH recommended exposure limit (REL) for ultrafine nano-TiO2 (0.3 mg/m3). Electron microscopy analysis of the samples exceeding the NIOSH REL for ultrafine nano-TiO2 during spraying revealed that the nano-TiO2 particles were predominantly in the size range of 80 to 147 nm. Respirable dust concentration and PNC were positively correlated for higher-risk activities, with peak PNC observed at the workplaces where spraying applications were performed. To our knowledge, this is the first study evaluating nano-TiO2 workplace exposure in Singapore. Exposure levels were generally low, likely due to prevalence of small-scale and research-based applications but varied significantly across workplaces for activities such as spraying, bulk loading and manufacturing. Singapore's current regulatory approach (TR 73) establishes exposure limits but lacks specific guidance on control measures. A more holistic regulatory framework is needed, providing tailored recommendations for diverse workplace exposure scenarios.

Integrating engineered nanomaterials into sustainable plant disease management: Evaluating efficacy, driving factors, and mechanistic understandings.

Advances and challenges in the ecological risk assessment of engineered nanomaterials in aquatic ecosystems: A review.

Engineered nanomaterials (ENMs) exhibit novel properties that offer significant benefits across various industrial sectors and are increasingly present in consumer products worldwide. However, safety assessments have predominantly focused on specific regions, such as the European Union (EU), leaving potential human and environmental risks in other areas insufficiently understood. The absence of a globally harmonized regulatory framework further complicates risk management, due to data variability, uncertainty, and the complexity of ENMs. In response, some countries have developed diverse tools and methodologies to address these regulatory challenges. This article presents an overview of current safety assessment methodologies and reviews international regulatory approaches for ENMs. It also proposes general recommendations for initiating a regulatory framework in Mexico, informed by existing scholarly insights. The aim is to support the development of locally relevant strategies that align with international best practices.

Amyloid-β (Aβ) fibrillation is a spontaneous, thermodynamic process governed by nucleation and elongation. While many studies have explored the ability of engineered nanomaterials (ENMs) to modulate Aβ fibrillation, such as inhibitors, promoters, and dual-modulators, the key physicochemical property of ENMs that determines this behavior remains unclear. In this study, we developed a comprehensive library of ENMs with well-controlled physicochemical properties, including surface charges, morphologies, and hydrophilicity, to systematically investigate their effects on Aβ40 fibrillation. We identified hydrophilicity as the primary determinant of ENM-mediated modulation, rather than surface charge or morphology. Thioflavin T (ThT) kinetics assays indicated that hydrophilic ENMs exhibited bidirectional modulation, both promoting and inhibiting fibrillation depending on concentration. This bidirectional effect results from a competition between accelerated nucleation and decelerated elongation. While hydrophobic ENMs exhibited only unidirectional inhibition from the initial nucleation phase, two-dimensional-NMR (2D-NMR) mechanism studies indicated that this difference resulted from specific interactions with Aβ40 residues. Hydrophilic ENMs targeted hydrophilic residues involved in elongation, including Arginine R5, Glycine G9, G25, G33, G37, and G38, Lysine K28, and Alanine A30, while hydrophobic ENMs bound to hydrophobic residues critical for nucleation, such as I31. These findings provide mechanistic insight into NP-peptide interactions and lay a foundation for the rational design of nanomaterials to modulate amyloid fibrillation.

The proliferating incorporation of engineered nanomaterials (ENMs) in everyday consumer products, such as sunscreen, poses concerns about the dermal exposure effects of these ENMs. Well-characterized ENMs, titanium dioxide and zinc oxide, are utilized as models to understand ENM interactions with skin cells and their influence on wound closure. The ENMs, at relevant exposure doses, have been demonstrated to promote the wound closure process in both in vitro and ex vivo skin explant models. Mechanistic studies reveal that the wound closure process is modulated by intracellular ROS production, with the involvement of autophagy, JNK, and ERK signaling pathways, to promote ENM-induced focal adhesion turnover, microtubule remodeling, and cell migration.

It is essential to adopt a systematic approach for assessing the risk associated with the deposition and dispersion of engineered nanomaterials (ENMs) in the environment. An adequately designed risk management system is crucial to protect human health and life. The comprehensive characterization of the properties of ENMs is a challenging undertaking due to the various shapes, sizes, and types of nanomaterials currently available. The application of machine learning (ML) methods represents a potential solution that can assist in this process. From the environmental perspective, one of the most critical characteristics of ENMs is zeta potential (ζ). Our research findings have led to the development of a predictive model that enables the estimation of ζ for nano-MeOx, utilising experimentally determined pH values and simple descriptors of the nano-structure. We have projected the optimal methodology using an algebraic approach of integrating nano-QSPR (Quantitative Structure-Property Relationship) models to obtain the best possible explanation, avoid losing important information, and produce a robust consensus model for five selected MeOx (Al2O3, CeO2, Fe2O3, MnO2, ZnO). The developed model demonstrates a high predictive ability (QF1-3 > 0.897) and goodness-of-fit (R2 = 0.912). A distinctive attribute of the model we have devised is its capacity to rapidly approximate ζ through the utilization of an environmental variable (pH) in conjunction with readily calculable structural descriptors.

Quercetin-conjugated gold-decorated simonkolleite nanohybrids: Insights into oxidative stress and antibacterial activity.

Abstract Environmental exposure and impact of engineered nanomaterials (ENMs) have the potential to induce various undesirable effects. To mitigate these effects, the safer-by-design (SbD) approach for ENMs synthesis and formulation of nano-enabled products (NEPs) has been proposed. The current study investigated the application of SbD (to reduce the ENMs’ release from the product matrix) in the formulation of skin moisturisers, focusing on reducing ENMs concentrations in the NEPs. Specifically, industrial cosmetic titania (nT-Avo) was incorporated into skin moisturisers at different concentrations [1.5, 5, and 10% (w/v)] to assess the effects of T-Avo reduction on the potential for ENMs environmental exposure. The incorporated needle-like (31.45 × 9.499 nm) nT-Avo particles coated with a silicon (Si) layer were negatively charged and in the rutile phase. The incorporation into skin moisturisers did not affect their physicochemical properties; nT-Avo maintained their morphology (needle-like shape, 28.68–32.53 × 10.50–11.24 nm), negative zeta potential (− 44.04 to − 76.67 mV) and Si coating. The reduction of T-Avo from 10 to 5% reduced nT-Avo release by 30%, indicating the effectiveness of reducing ENMs in the NEPs to reduce their environmental exposure. ENMs concentration reduction from 10 to 5% did not affect the functional efficiency; the moisturiser met the required UV protection standards (SPF = 21). However, reduction from 5 to 1.5% indicated the loss of functional efficiency (SPF 21.01 vs 2.72). The current findings illustrate that it is possible for manufacturers to minimise nanopollution at the product formulation stage whilst retaining envisaged nanofunctionality. The study demonstrated SbD application for commercial products. For products that exhibit a high likelihood to emit ENMs, manufacturers are encouraged to investigate the optimisation of environmental safety-informed design of their products.

The development ofnew approach methodologies (NAMs) to replacecurrent in vivo testing for the safety assessmentof engineered nanomaterials (ENMs) is hindered by the scarcity ofvalidated experimental data for many ENMs. We introduce a frameworkto address this challenge by harnessing the collective expertise ofprofessionals from multiple complementary and related fields (“wisdomof crowds” or WoC). By integrating expert insights, we aimto fill data gaps and generate consensus concern scores for diverseENMs, thereby enhancing the predictive power of nanosafety computationalmodels. Our investigation reveals an alignment between expert opinionand experimental data, providing robust estimations of concern levels.Building upon these findings, we employ predictive machine learningmodels trained on the newly defined concern scores, ENM descriptors,and gene expression profiles, to quantify potential harm across varioustoxicity end points. These models further reveal key genes potentiallyinvolved in underlying toxicity mechanisms. Notably, genes associatedwith metal ion homeostasis, inflammation, and oxidative stress emergeas predictors of ENM toxicity across diverse end points. This studyshowcases the value of integrating expert knowledge and computationalmodeling to support more efficient, mechanism-informed, and scalablesafety assessment of nanomaterials in the rapidly evolving landscapeof nanotechnology.

This research critically examines the synergistic integration of nanotechnology and green nanotechnology as a disruptive framework for addressing dual imperatives of sustainable environmental remediation and next-generation clean energy systems. By exploiting the physicochemical uniqueness of nanomaterials- such as quantum confinement, surface plasmon resonance, enhanced electron mobility, and high surface-to-volume ratios- this study elucidates the multifaceted mechanisms by which engineered nanomaterials (ENMs) facilitate the adsorption, catalysis, degradation, and real-time sensing of diverse pollutants across air, water, and soil matrices. Importantly, these processes are governed by the foundational principles of green chemistry and sustainable engineering, prioritizing biogenic synthesis, non-toxic precursors, low-energy fabrication, and end-of-life biodegradability to mitigate ecological and health risks. The study further explores how nanostructured components- including perovskite nanocrystals, quantum dots, plasmonic nanoparticles, and nanocomposites- redefine the performance boundaries of photovoltaic cells, fuel cells, thermoelectric generators, and electrochemical storage devices. The convergence of nanogenerators (TENGs, PENGs), nano-enabled supercapacitors, and AI-optimized hybrid energy modules is shown to enable continuous, resilient, and decentralized electricity generation, particularly in climate-vulnerable and off-grid regions. A novel AI-augmented architecture incorporating nano-sensors, edge computing, and digital twins is proposed to facilitate predictive diagnostics, adaptive control, and lifecycle optimization of these intelligent energy ecosystems. Moreover, a comprehensive cradle-to-grave life cycle sustainability assessment (LCSA) evaluates carbon intensity, energy return on investment (EROI), nanotoxicological profiles, recyclability, and circularity potential. This ensures that technological advancement aligns with planetary boundaries and long-term ecological integrity. The research underscores the ethical imperative of responsible innovation, advocating for regulatory convergence, precautionary design, and stakeholder-inclusive deployment strategies. By fusing material science, environmental engineering, artificial intelligence, and sustainability science, this study presents a cutting-edge, multidisciplinary roadmap for leveraging nanotechnology and green nanotechnology as accelerators of global ecological restoration and clean energy transition.

Simulating the fate and transport of ZnO nanoparticles in a Tidal River: Coupling a form-specific material flow analysis model to a hydrodynamic fate model.

Engineered nanomaterials (ENMs) are rapidly emerging as transformative agents in fields such as drug delivery, imaging, and environmental remediation, offering unique properties not seen in bulk materials. Despite their promising applications, concerns have been raised about their potential toxicity to human cells. Traditional methods of evaluating nanomaterial toxicity are often slow, expensive, and fail to fully replicate the complex biological processes that occur in the human body. In recent years, artificial intelligence (AI) has emerged as a powerful tool to accelerate toxicity profiling by enabling high-throughput analysis of data and predictive modeling. This research explores the role of AI in the toxicity assessment of ENMs, with a focus on predicting their effects on human cells. By utilizing machine learning algorithms and integrating multi-omics data, AI can provide a more comprehensive and efficient approach to profiling the toxicological risks of ENMs, facilitating the development of safer nanomaterials.

Life cycle assessment and engineered nanomaterials: looking to the past to inform the future - considering nanoscale silver as an example.

A new approach for simultaneous measurement of aerosol respiratory deposition and its chemical composition: Health risk assessment of metal engineered nanomaterials in consumer spray aerosols.

Silver nanoparticle (AgNP), neurotoxicity, and putative adverse outcome pathway (AOP): A review.

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.

Advances in nanotechnology have enabled fabrication of nanomaterials with defined structures that areincreasingly being used for commercial purposes. Unlike chemical toxins, nanomaterials have unique interactions with macromolecules and cells based on their molecular size and interfacial physiochemistry. Adverse human health impacts due to occupational and environmental exposures to engineered nanomaterials (ENMs) are therefore of concern. Although the impact of ENMs on biological systems is still not clearly understood, strong evidence suggests that nanomaterials are present in human fluids and tissues. Effective and feasible hazard assessment of ENMs is urgently needed to guide regulation and policy-making and support the development of benign next generation ENMs. Beyond the physical parameters of the NMs themselves, the surrounding biological system has been shown to influence NM behavior, the nano-cellular interface, and subsequent biological responses.It has recently been established that ENMs, upon entry into a physiological environment, exhibit a tendency of physical adsorption with proteins, peptides, lipids and amino acids to render a "biocorona" that may influence the bioavailability and distribution of ENMs within the host system, at the cellular, tissue and whole organism level. Consequently, research on the health and safety implications of ENMs must include assessments of how the biocorona may impact toxicity and lead to a new 'biological' identity of the ENM.Although ongoing research suggests that almost every organ and organ system may be affected by ENMs, in this review we will focus on the main pathogenetic mechanisms and on key organ and organ systems such as the lung, the skin and the gastro-intestinal tract; we will also highlight several challenges associated with a comprehensive evaluation of their toxicity, including the vast and diverse array of ENM products, dependence on physicochemical characteristics and exposure matrices, and difficulties in quantifying dosimetry and dose-response. Possible attempts to overcome these challenges are also discussed.

Although the debate among the scientific community is still open to identify the parameters which better represent engineered nanomaterials (ENMs) toxicity, numerous methodological approaches to assess workers exposure to airborne ENMs have been proposed. The measurement of exposure to ENMs is a critical step in the analysis of the potential risks for workers and the distinction of engineered nano-objects from the background is highly important to understand the contribution of specific sources. In 2015, OECD reviewed the major published strategies and promoted a harmonized three-tiered approach to measure and assess the airborne exposure to engineered nano-objects in the workplace, with the aim also to balance costs and effectiveness of investigation efforts. In this framework this study proposes the preliminary results of occupational exposure measurements conducted in both industrial and laboratory workplaces in which different types of nanmaterials were used. The results of this study will be useful to validate the proposed exposure measurement strategy.

Nanotechnology has emerged as a transformative approach for improving soil health and agricultural productivity through its applications in soil remediation, fertilization, and carbon sequestration. In soil science, nanotechnology involves the use of engineered nanomaterials (ENMs) such as nanoparticles, nanofibers, nano clays, and carbon-based nanomaterials to address challenges related to soil contamination, nutrient management, and carbon sequestration. Recent advancements in nanotechnology-based soil management, focusing on the role of nanomaterials such as nanoscale zero-valent iron (nZVI), biochar, graphene oxide, nano clays, and metal oxide nanoparticles. Soil remediation using nanomaterials demonstrates high efficiency in removing heavy metals, organic pollutants, and pathogens through adsorption, catalytic degradation, and redox reactions, achieving contaminant removal rates exceeding 90%. Nano fertilizers enhance nutrient use efficiency by 30-40%, promoting crop productivity and minimizing nutrient losses. Carbon sequestration efforts using biochar and graphene oxide have been shown to increase soil organic carbon storage by 15-40% through improved soil aggregation and organic matter stabilization. Despite promising results, challenges related to potential toxicity, long-term stability, scalability, and inconsistent regulatory frameworks persist. Addressing these concerns requires the development of eco-friendly nanomaterials, standardized testing protocols, and comprehensive risk assessments. Integrating nanotechnology with precision agriculture, digital farming, and biotechnology offers opportunities for synergistic effects that enhance soil health and agricultural sustainability. Collaborative efforts involving researchers, policymakers, and industry stakeholders are essential for advancing nanotechnology-based solutions to address global challenges related to soil degradation, food security, and climate change mitigation. Continued research and international cooperation will be important in optimizing the safe and effective use of nanotechnology in soil science.