Three-dimensional (3D) printing technology is emerging as a transformative tool in eco-environmental research. It innovates environmental analysis technologies, augments environmental purification, alleviates environmental health risks, and fosters ecological sustainability. Nevertheless, most current applications of 3D printing in the eco-environmental domain remain largely confined to laboratory testing stages, with limited translation to large-scale and real-world deployment. In this viewpoint, we review recent progress and critical challenges within this field, while providing strategic perspectives for its future trajectory. We highlight the imperative to integrate cutting-edge 3D printing techniques into eco-environmental research, advance sustainable printing materials, and develop integrated multifunctional devices for environmental monitoring and remediation. Furthermore, we introduce a pioneering conceptual framework: self-sustaining composite artificial biosystems. Here we envision it as a bionic tree, a 3D-printed biohybrid construct that integrates an open microfluidic scaffold with engineered living materials to autonomously maintain biological activity through self-driven internal mass transport. While emulating key morphological and physiological features of natural plants, the bionic tree transcends its natural analogue by enabling synthetic biology-guided environmental remediation, CO2 sequestration, and energy production. We provide an in-depth analysis of the rationale behind this concept, assess its technical feasibility, and present a developmental roadmap for this emerging research direction. Our insights are poised to amplify the contribution of 3D printing to the eco-environmental sector, thereby facilitating environmental pollution control and sustainable development.

Bioessential elements are essential for maintaining reproductive function, yet their homeostasis may be perturbed during aging. The dynamic regulation of these elements during aging remains insufficiently characterized. Here, a multielement single-cell inductively coupled plasma mass spectrometry (SC-ICP-MS) method was established for the quantification of seven bioessential elements, including iron (Fe), copper (Cu), calcium (Ca), zinc (Zn), magnesium (Mg), phosphorus (P) and manganese (Mn). This method was optimized using an integrated strategy to balance sensitivity, transport efficiency, and signal-to-noise ratio, and subsequently applied to quantify elemental contents in sperm collected from mice at different ages. Distinct age-dependent patterns were observed at the single-sperm level. Fe, Cu, and Ca exhibited early life maxima, whereas Zn, Mg, and P reached peak levels in midlife; Mn remained consistently low across all age groups. Interestingly, elemental heterogeneity followed a conserved inverted U-shaped trajectory, reaching a maximum at week 40. Correlation network analysis revealed a significant association between Fe and Mn at the content level, whereas elevated P content and increased heterogeneity were associated with reduced sperm concentration and impaired morphology. Functionally, Zn content was positively correlated with sperm motility, whereas elevated P content and increased heterogeneity were associated with reduced sperm concentration and impaired morphology. Ca, P, Mn, and Fe were more susceptible to dysregulation linked to compromised sperm function, whereas Mg, Zn, and Cu were associated with beneficial outcomes. These findings provide single-cell insights into age-dependent elemental homeostasis and its functional implications for male reproductive aging.

Titanium alloys have emerged as the primary material for orthopedic implants, particularly with the advent of 3D-printing technology that has revolutionized the fabrication of complex, biomimetic porous structures. However, the potential release of wear particles poses a critical safety concern, and due to the relatively short clinical history of these novel implants, in vivo data evaluating their safety profile is still limited. Herein, this study established a single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS) method to quantify low-concentration Ti-containing nanoparticles (Ti-NPs) and total Ti in peri-implant tissues, blood, and major organs of rabbits at 1, 2, 3, and 4 months following implantation. A split-body design was utilized to compare HA-coated and uncoated 3D-printed Ti-6Al-4V implants. The results showed that Ti-containing nanoparticles (Ti-NPs) were detected across all peri-implant tissues, blood, and major organs, with the majority being nanosized (< 100 nm). In the peri-implant tissues, the Ti-NPs exhibited smaller sizes and lower concentrations in the HA-coated group compared to the uncoated group, demonstrating the protective barrier effect of the coating. Furthermore, the release profile showed that ionic titanium was the dominant species (Ti-NPs < 10%), with a distinct systemic distribution pattern. Specifically, by the fourth month, total Ti concentrations in organs decreased sharply due to excretion, whereas Ti-NPs conversely accumulated, with the spleen identified as the primary reservoir. Overall, this work provides important evidence and offers useful guidance for the safety evaluation of 3D-printed implants.

Microbial mercury methylation is the key step responsible for the high toxicity and bioaccumulation potential of mercury. Since metabolic pathways serve as a bridge between mercury methylation and microbial activity, studying mercury methylation from the perspective of metabolic pathways will offer valuable insights into its underlying mechanism and integration into microbial metabolism. This review aims to summarize current understanding of the metabolic pathways that supply methyl groups for mercury methylation and to elucidate the relationships between them. The acetyl-coenzyme A pathway is extensively studied and well recognized for its role in methyl group transfer. The Wolfe cycle, representing the methanogenesis pathway in methanogenic archaea, has recently been identified as a distinct source of methyl groups contributing to mercury methylation. In addition, at the chemical level, S-adenosyl-L-methionine from the methionine biosynthesis pathway has been shown to donate a methyl group to mercury via the HgcAB complex, although this process has not yet been validated in vivo. Finally, the dimethylsulfoniopropionate degradation pathway is proposed as a speculative and potential route for mercury methylation. By integrating these pathways, we provide a comprehensive overview of their interconnections, demonstrating that microbial mercury methylation is embedded within the broader framework of one-carbon metabolism. The close association between methylation and one-carbon flux suggests that mercury methylation may function as an interspecies competition strategy that enhances microbial survival in mercury-rich environments. This pathway-centered perspective advances our understanding of the biochemical basis of microbial mercury methylation and may inform future research into its environmental controls and microbial ecology.

Metal-containing particles are the main component of the positive electrode in lithium-ion batteries (LIBs). However, the occurrence and behavior of these particles in wastewater remain inadequately understood. In this study, single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS) was employed to systematically track metal-containing particles in wastewater from a ternary precursor (TP) production facility and a full-scale wastewater treatment plant (WWTP). Multiple metal particles, including Ni-, Co-, Mn-, Al-, Cu-, and Zn-containing particles, were detected with size ranges of approximately 20-120 nm, 15-200 nm, 10-800 nm, 15-730 nm, 20-120 nm, and 25-925 nm, respectively. The above sentence in abstract should be revised as: Multiple metal particles, including nickel (Ni)-, cobalt (Co)-, manganese (Mn)-, aluminum (Al)-, copper (Cu)-, and zinc (Zn)-containing particles, were detected with size ranges of approximately 20-120 nm, 15-200 nm, 10-800 nm, 15-730 nm, 20-120 nm, and 25-925 nm, respectively. Characterization using transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy (TEM-EDS) revealed that these particles consisted of multiple metals and were partly in an agglomerated state. Further analysis demonstrated that the metal-containing particles showed metal-specificity in their dynamic transfer and transformation. Whereas Ni-, Co-, and Al-containing particles exhibited significant size variations, Mn-, Cu-, and Zn-containing particles showed little change. The particle number concentration decreased for Mn, Al, and Zn, increased for Co and Cu, while it remained stable for Ni. This study provides critical insights for improving treatment and management strategies of metal-containing particles in wastewater.

RATIONALE:As quadrupole and ion trap mass analyzers are miniaturized toward millimeter scales, fabrication quality increasingly constrains analytical performance. Micrometer-scale deviations in electrode geometry, surface finish, and assembly alignment can introduce higher order multipole fields, thereby degrading resolution, sensitivity, and ion transmission. Conventional precision machining and sequential assembly therefore face increasing difficulty in simultaneously achieving field fidelity, geometric complexity, and scalable integration. METHODS:This narrative review compares conventional subtractive manufacturing with four advanced routes: microelectromechanical systems (MEMS), low-temperature co-fired ceramics (LTCC), additive manufacturing (AM), and printed-circuit-board (PCB)-based architectures. A process-problem-performance framework is used to link each process to the error modes it mitigates or introduces and to the analytical performance affected. RESULTS:MEMS provides high planar registration but remains limited in forming true 3D electrode surfaces. LTCC reduces assembly burden and supports multilayer integration but is constrained by shrinkage and feature resolution. AM offers monolithic 3D freedom, although electrode-grade performance requires surface engineering, metallization, and control of dielectric and vacuum-related effects. PCB-based architectures enable rapid prototyping and field synthesis but usually lack field-critical geometric precision. Across these routes, no single technology simultaneously maximizes fabrication precision, geometric freedom, and scalable integration. CONCLUSIONS:Hybrid manufacturing strategies that allocate field-critical, structural, interconnect, packaging, and calibration functions to complementary processes represent the most practical route toward reproducible next-generation quadrupole and ion trap mass analyzers. Future progress will depend on standardized comparisons of fabrication tolerance, surface quality, RF compatibility, material stability, and demonstrated analytical performance.

Fe-reducing bacteria (FRB) play a pivotal role in regulating the biogeochemical cycling of mercury (Hg) and its associated ecological risks, while a systematic understanding of the molecular targets affected by Hg stress in these bacteria remain limited. In this study, we employed gel electrophoresis coupled with inductively coupled plasma mass spectrometry (GE-ICP-MS) to investigate the protein interaction responses to Hg stress in the model FRB Geobacter sulfurreducens PCA. This approach allowed us to identify Hg-binding proteins and characterize their functional implications. For the first time, we successfully resolved metalloproteins in this strain using GE-ICP-MS and identified 13 specific Hg-binding proteins, revealing critical molecular targets beyond previously known pathways. Functional analysis indicated that Hg binding to key enzymes in central carbon metabolism (gapA, eno, and gltA) and the ATP synthase subunit (atpD) induced a cellular energy deficit. Concurrently, Hg impaired protein folding (groES and degP) and synthesis machinery (tuf1 and rplI), thereby disrupting the production and function of essential proteins. These processes initiate a self-limiting cascade that ultimately suppresses the Hg methylation by disrupting its essential prerequisites, which provides a mechanistic explanation for the observed fluctuation of methylation ability. These findings demonstrate the utility of GE-ICP-MS in microbial metallomics, offering​ new molecular insights into the mechanisms of microbial Hg adaptation.

Immune modulation is crucial for male reproduction and fertility. Metals and metalloids (metals) have been extensively studied for their immunomodulatory effects. Whether metal exposure affects semen quality through immune modulation is unclear. In the present study, we explored the associations between exogenous metals within immune cells, immune cell proportions, and semen quality among 84 healthy men who repeatedly provided 266 semen samples over 90 days. We employed mass cytometry (CyTOF) technology to identify immune cells in semen and measured exogenous metals in these cells at the single-cell resolution. After adjusting for potential confounders, most detected metals in immune cells were inversely associated with the proportion of immune cells in semen samples (all p < 0.05), indicating the adverse effects of exogenous metals on immune cells. The proportion of immune cells showed N-shaped, nonlinear associations with sperm concentration, total count, progressive motility, and total motility. Mediation analyses showed that the percentage of indirect effects of exogenous metals on sperm quality parameters via immune cells ranged from 15.11% to 54.29%. Overall, our findings unravel the indirect effects of exogenous metal exposure on male reproductive health via immune cells, contributing valuable insights into the complex interplay between environmental factors, immune cells, and human semen quality.

Lead (Pb) is known as a neurotoxicant, posing a global public health threat. Although Pb exposure is reported to be associated with brain functional impairment, there remain gaps to directly clarify their links and how the environmental lead entry into brain is rarely known. This study explored the entry pathway of atmospheric Pb to brain and lung through comprehensive profiling of Pb characteristics (distribution, nanoparticle characterization and isotope ratio) in the biological and atmospheric samples collected from a typical pollution area. The Pb distribution showed the targeted accumulation of Pb in brain and its descending trend with distances in both tissues and atmosphere indicated the direct transportation of Pb to lung due to point emission of atmospheric Pb. Then the identical characteristics of Pb-containing nanoparticles (PbNPs) in the lung (two sizes: 35 ± 6 nm and 52 ± 24 nm) and atmospheric (37 ± 6 nm and 53 ± 24 nm inside the smelter) samples, which was identified to be the mixture of PbSO4 and Pb5[PO4]3Cl particles, suggested the origination of exogenous PbNPs in lung from atmosphere through direct respiration. Finally, the highly correlation of Pb isotope ratios in brain and lung, liver and kidney, and the significant difference between the two groups (p < 0.0001) indicated Pb in brain and lung was most likely directly inhaled after exposure to particulate pollution in atmosphere, but not from the liver through circulatory system. This is the first time to apply Pb isotopic characteristics in biological organs for investigating the Pb circulations and possible entry route to brain, which would provide direct evidence and a crucial link to understand the brain diseases caused by atmospheric Pb.

Inductively coupled plasma mass spectrometry (ICP-MS) has demonstrated significant capabilities in the analysis of single events, such as single cells and particles. Researchers have been actively pursuing innovations in ICP-MS sample introduction systems to enhance their transport efficiency, as this is critical for ensuring the accuracy of single-event analysis. However, the majority of prior studies have relied heavily on empirical approaches, with limited attention given to the individual characteristics of particles from a theoretical perspective and a lack of efficient manufacturing tools for optimizing related components. Herein, we developed a high-efficiency sample introduction system for single-event ICP-MS analysis by integrating the computational simulation-aided design, precise 3D printing manufacturing, and rapid experimental testing process. For the first time, we simulated the transport trajectories of individual particles passing through the spray chamber, providing theoretical guidance for the design and optimization process. The statistical analysis of particle trajectories revealed that under the absorption boundary condition, particles between 20 and 100 nm achieved transport efficiencies exceeding 18.8%. In comparison, particles larger than 100 nm exhibited 0% transport efficiency due to increased deposition within the spray chamber. The spray chamber was fabricated in-house using a range of 3D printing technologies and materials, streamlining the process and reducing the cost for both manufacturing and validation. Further optimization of the operating parameters, including an increase in temperature, resulted in a notable transport efficiency of 61.1%. The workflow introduced in this study has the potential to transform the research and development of critical mass spectrometry components moving forward.

Metal-containing nanoparticles (MNPs) ubiquitously exist in the environment and organisms, playing distinct roles in the fate and toxicity of metals. However, the extraction and analysis of the MNPs in biological samples is still a great challenge and the interferences of other metal species and complex matrices remains unclear. In this work, we established a method for efficient extraction and accurate analysis of MNPs in biological samples to eliminate the interference caused by metal ions and biological matrices based on the alkali extraction and single particle mode inductively coupled plasma mass spectrometry (SP-ICP-MS). Obvious interference signals of lead-containing nanoparticles (PbNPs) were found in various biological matrices (liver, brain, bile, intestine, stomach), causing false positive results or overestimation of PbNPs. Then, a novel strategy using EDTA and ultrasonic during the TMAH extraction process were proposed to successfully eliminate the interferences due to the strong and competitively binding of EDTA to Pb ions, which was identified as ionic signals in SP-ICP-MS and resulted in the elimination of interferences. Finally, this method was successfully applied for the extraction, characterization and quantification of PbNPs in different biological tissues collected near a power plant, revealing the occurrence of PbNPs in stomach, intestine and liver tissues and indicating their oral exposure and potential translocation. This method could be universally applied for the efficient extraction and accurate analysis of MNPs in biological samples and thus provided a reliable and powerful tool for the investigation of the occurrence, fate and toxicity of MNPs in environmental and organisms.

High blood lead (Pb) levels have long been a significant environmental issue affecting the health and development of adolescents. However, the main reasons behind this phenomenon, especially the absorption and transportation processes of Pb in the intestine, have not been elucidated, which is the major barrier to reducing blood Pb levels in the human body, especially in adolescents. In this study, we explored the intestinal absorption process of Pb in rats of different ages at environmentally relevant concentrations. The results indicated that albumin serves as a crucial mediating role in the process of gradually decreasing Pb levels with age (aging). Next, experiments with induced senescence and the addition of albumin confirmed that binding to albumin facilitates the absorption and transportation of Pb. Furthermore, a low-protein diet can reduce Pb levels by approximately 50%, possibly due to a decrease in the synthesis of albumin resulting from reduced raw materials. Collectively, these findings reveal the potential reasons for high Pb levels in adolescents, elucidate the influence of albumin on Pb absorption and transportation, and provide an alternative pathway for regulating intestinal Pb absorption in adolescents at ambient concentrations.

BACKGROUND:Mercury (Hg), a global pollutant, poses health risks to humans and mammals even at low exposure levels. However, current analytical methods face challenges in quantifying cellular Hg at ultralow concentrations. In this study, we developed a sensitive single-cell inductively coupled plasma-mass spectrometry (SC-ICP-MS) method by utilize a temperature-controlled introduction system to trace Hg in individual mammalian cells. RESULTS:Sensitivity was significantly enhanced through a personalized tuning process, which increased the instrument sensitivity of Hg ions (Hg2+) by 28.8 %. Through optimization of detection conditions, we achieved an improved transport efficiency (TE) of 27.3 % for single-cell detection in THP-1 cells. By implementing the comprehensively optimized method, we attained an exceptionally low single-cell-level Hg mass detection limit (LODm) of 0.01 fg per cell, coupled with a cell density detection limit (LODd) of 8.1 × 102 cells mL-1, resulting in a Hg concentration detection limit (LODc) of 0.008 ng L-1. This validated method demonstrated robust applicability across multiple mammalian cell types, revealing that Hg content (m) at the single-cell level exhibited exponential growth with increasing exposure concentration, while the heterogeneity of Hg displayed an initial rise before reaching a plateau or decreasing. SIGNIFICANCE:This study establishes a highly sensitive and reproducible method for monitoring single-cell Hg content and heterogeneity at environmentally low exposure levels. The technical advances provide a robust methodological foundation for assessing element-specific toxicity across different mammalian cell types, supporting the health risk evaluation in low-dose scenarios.

The fate of metals within biological systems is determined by their associated binding partners, specifically protein ligands. However, the mechanisms by which these protein targets regulate the transport of metal pollutants remain unclear. Here, protein-binding patterns were identified as drivers of the transport of mercuric compounds (methylmercury and inorganic mercury) in the bloodstream. We systematically investigated the transport of mercury (Hg) in rats following oral administration and analyzed the time-resolved patterns of Hg-binding proteins in the blood. Our findings demonstrated that Hg was differentially distributed between plasma and red blood cells (RBCs) over time, suggesting distinct transport pathways mediated by specific protein interactions. Methylmercury (MeHg) preferentially bound to hemoglobin and carbonic anhydrase in RBCs, together accounting for more than 97% of protein-bound MeHg. This selective binding retained MeHg within the RBCs and significantly prolonged its circulation time. In contrast, inorganic mercury (HgCl2) displayed a broader and more diverse protein-binding pattern. In RBCs, it bound primarily to hemoglobin and galectin-5, whereas in plasma, albumin and glutathione peroxidase 3 (Gpx3) were identified as its major binding partners. These protein-binding patterns drive the differential biological fates of mercury. The higher ratio of MeHg to proteins in RBCs resulted in a longer vascular circulation lifetime of MeHg in blood, leading to the prolonged transfer of MeHg from the blood to the brain. Conversely, the higher plasma protein binding of HgCl2 facilitated its partitioning from the blood into tissues such as the kidney and liver, where it could be rapidly cleared and excreted. In summary, Hg-binding proteins play a crucial role in regulating their retention in the blood and their subsequent transfer to tissues.

This paper reviews the most efficient and direct solution to existing assembly techniques in three-dimensional (3D) printing and classifies them into macroscopic, microscopic, and mesoscopic categories. This paper discusses the challenges and possible methods for simultaneously achieving multi-material, multi-precision, and large-volume products. 3D printing with high-speed production and cost-effectiveness offers new manufacturing possibilities. Printing materials with different properties can be used to produce a variety of products with reduced weight and improved performance; however, 3D printing faces limitations in simultaneously creating multi-material parts, printing components with varying precision, and accommodating diverse product sizes. Strategies have been developed to overcome the limitations of 3D printing, focusing on hardware improvements and the exploration of 4D printing. However, its widespread implementation awaits ongoing experimentation and investment. This review illustrates how assembly involves precise part connections for robust structures in various manufacturing processes to satisfy specific application requirements. Traditional assembly is characterized by low technical requirements and minimal specialized tools or staff. Considering 3D printing characteristics and application size distribution, this study discusses three assembly methods: macro-assembled, micro-assembled, and meso-assembled structures. Secondary light curing enables modular manufacturing for large-scale and microfluidic systems, and step-by-step printing involves multiple stages to improve the surface activity and adsorption of stable chemical bonds between different materials. Over the past several decades, 3D printing has made significant advancements and found applications in various fields, including construction, machinery, and medical treatment. This paper illustrates assembly technologies that can satisfy these multi-material, multi-precision requirements.

Single-cell inductively coupled plasma mass spectrometry (SC-ICP-MS) is an emerging technique to investigate metal heterogeneity in individual cells. However, due to the absence of consistent calibration and suitable stabilization strategy for cells, accurate quantification of cellular heterogeneity and the content of metals remains a challenge. Herein, an accurate quantification method for the content and heterogeneous distribution of metals among individual microalgae cells was developed based on SC-ICP-MS using dual-calibration strategies and robust pretreatment methods. Gold nanoparticles (AuNPs) were used as calibration for measuring metal contents in single cells, but it would lead to a 13.6-63.1% underestimation of cell numbers due to inaccurate detection of cells' transport efficiency. To avoid this inaccuracy, we proposed an additional calibration strategy to measure cellular transport efficiency and cell numbers using endogenous Mg, enabling a more accurate assessment of cell heterogeneity. Then, an effective pretreatment method was optimized through fixation of cells with glutaraldehyde for 1 h to maintain the cellular stability and obtain accurate results, with satisfactory recoveries for cell number (98.4%) and Mg contents (91.7%), even after long-time storage. After optimization, the proposed method showed high sensitivity and repeatability in both cellular metal contents (Mg, Hg, Cd, and Co) and cell number, with detection limits (LODs) to be 0.14-0.53 fg/cell and 5.5 × 103 cells/mL, respectively. Finally, the proposed method was successfully used for detecting various metals and their heterogeneity in Synechocystis sp. PCC 6803 cells provided an accurate and robust tool for investigating the uptake and heterogeneous distribution of metals in microalgae.