Micro

Microfluidics provides precise control of microscale fluid transport and has become central to biomedical, pharmaceutical, and industrial technologies. However, conventional fabrication methods such as photolithography and soft lithography require cleanroom facilities, use costly materials, and offer limited capability for constructing complex or multi-material architectures. This review highlights emerging manufacturing strategies, focusing on polymer-based micro-milling as an accessible and cost-effective alternative for microfluidic device production. Advances in micro-milling now enable the fabrication of microchannels and functional features with improved dimensional accuracy and surface quality, while additive manufacturing offers complementary rapid prototyping and design flexibility. Micro-milling is particularly promising for rapid prototyping of polymeric biosensor chips designed for point-of-care diagnostics. The technique supports diverse materials and eliminates reliance on cleanroom processing. Critical parameters, including tool geometry, spindle speed, and feeding rate, strongly influence fidelity and surface roughness, which directly affect biosensor sensitivity. Despite its advantages, challenges such as tool wear, burr formation, and limits on minimum feature size continue to hinder reproducibility. Recent progress in toolpath optimization, hybrid additive–subtractive methods, and real-time process monitoring shows the potential to overcome these barriers. Overall, micro-milling offers a scalable and economical route for fabricating accessible microfluidic and biosensing platforms, with future work needed to standardize processes and improve integration with surface functionalization methods. Full article

The rapid and selective discrimination of microplastics (MPs) is a critical analytical challenge, particularly as current carbon quantum dot (CQD)-based sensors often rely on single-wavelength “turn-on/off” or staining mechanisms that lack polymer-specific resolution. This work addresses these limitations by presenting a mechanism-driven fluorescence sensing platform using ultra-fine polyamide-derived carbon quantum dots (PACQDs; ~1.4 nm) to identify three prevalent MPs: polyamide (PA), polypropylene (PP), and polyethylene terephthalate (PET). Excitation–emission matrix (EEM) spectroscopy reveals polymer-specific photophysical responses: PAMPs and PPMPs induce fluorescence enhancement of 11.66% and 11.43%, respectively, whereas PETMPs cause net quenching (−4.61%) alongside a distinct, red-shifted emission band. Despite a common scatter-dominated peak at 290/308 nm, quantitative discrimination is achieved via integrated intensity and red/blue emission ratios (0.0137 for PAMPs, 0.0098 for PPMPs, and 0.0072 for PETMPs). Multivariate analysis reinforces this discrimination. Parallel factor analysis (PARAFAC) resolves the EEM data into three fluorescent components representing the intrinsic CQDs core and two interaction-induced surface states with a rank 3 model reducing the relative reconstruction error from 0.1625 to 0.1285. Principal component analysis (PCA) yields clear separation of the polymer classes, with the first two principal components capturing ~88% of the total spectral variance. ATR–FTIR spectroscopy provides direct molecular evidence for the underlying mechanisms: amide–amide coupling and interfacial rigidification for PAMPs; hydrophobic interaction without spectral shifts for PPMPs; and a synergistic interaction involving hydrogen bonding and π–π stacking for PETMPs. In particular, these polymer-specific fluorescence fingerprints are largely preserved in tap water, despite elevated background intensity and partial contrast attenuation, demonstrating the resilience of the EEM–chemometric approach under realistic matrix conditions. Collectively, the strong agreement between fluorescence metrics, multivariate signatures, and interfacial chemistry establishes a robust structure–property framework and positions PACQDs as a rapid, label-free, and matrix-tolerant platform for reliable microplastic discrimination in environmental analysis. Full article

Wire explosion (WE) inherently generates particle ensembles spanning the nano- to microscale, posing challenges for conventional characterization methods in terms of capturing the full particle population. To address this issue, spectrophotometric analysis combined with algorithmic spectrum reconstruction based on Mie theory and constrained distribution models were employed to characterize copper WE products formed in aqueous surroundings within the 4–12 kV discharge voltage range. Three independent fitting strategies, specifically a semimanual fitting, an evolutionary algorithm, and a grid search, were applied to retrieve the size distributions and relative shares of copper and copper oxide particles as a function of discharge voltage. Based on experimental and theoretical findings, lognormal and normal distributions across the 10–300 nm diameter range were assumed as constraints for oxide and metallic fractions, respectively. The reconstructed metallic copper population exhibited mean diameters ranging from 123 to 181 nm, while oxidized fractions followed lognormal distributions centred near 10 nm mode diameters. Voltage-dependent trends revealed an optimal discharge regime between 6 kV and 8 kV, where the exploded fraction reached approximately 63% and the metallic mass share exceeded 80%. These results confirmed that spectrophotometry represents an essential tool for the quantitative characterization of such complex, wide-range systems. Full article

The functionalization of molecules on C₆₀ is a promising engineering approach, as non-covalently governed fullerene surfaces facilitate reversible host–guest recognition, tunable electronic communication, and conformationally adaptive molecular adsorption. In this work, spin-resolved simulations using density functional theory (DFT) were conducted to examine the interaction between a newly identified arylalkanone isolated from the medicinal species Myristica ceylanica and the nanocarbon framework of C₆₀ fullerene, including doped configurations incorporating group III elements (B, Al, Ga, In and Tl). The results indicate that the arylalkanone binds to pristine C₆₀ through an exothermic, energetically favourable binding process, supporting thermodynamically viable molecular uptake. Among the doped models, B substitution exhibits the greatest overall thermodynamic preference; however, Al doping produces the most pronounced enhancement in binding energy, identifying the Al-doped configuration as the most effective surface-uptake architecture in relative terms. Across all complexes, a small amount of charge transfer is noted, signifying weak yet persistent electronic coupling between the ligand and the carbon carrier. Additionally, all doped fullerenes demonstrate induced magnetic behaviour, a property of increasing relevance in spintronics research, suggesting that these complexes may hold future value in spin-dependent electronic and molecular-recognition-guided nanoscale biomedical engineering. Full article

Nanomaterials have emerged as a pivotal driving force in the field of biomedicine due to their unique physicochemical properties. This article systematically reviews the design, synthesis, and characterization of novel nanomaterials, with a focus on their application advances in three key areas: targeted drug delivery, tissue engineering and regenerative medicine, and disease diagnosis and sensing. In drug delivery, nanocarriers enable precise drug targeting and controlled release through surface functionalization and stimuli-responsive design. In tissue engineering, nanocomposite scaffolds mimic the structure and function of the natural extracellular matrix, providing an ideal microenvironment for tissue repair. In disease diagnosis, nanomaterials significantly enhance the sensitivity and specificity of biosensors, promoting the development of real-time, non-invasive, and ultra-early detection technologies. The article further summarizes current challenges in the clinical translation of nanomedicine and envisions its future trends toward intelligence, personalization, and the integration of diagnosis and therapy. Full article

Malignant gliomas, including glioblastoma multiforme (GBM) and grade 4 astrocytoma, are the most common types of brain tumors in adults. Standard treatment for gliomas includes adjuvant chemotherapy, typically based on temozolomide, combined with radiotherapy. However, its effectiveness is severely hindered by the limited ability of drugs to cross the blood–brain barrier and by the hyperactivation of the canonical Wnt signaling pathway, which drives tumor cell survival. Therefore, innovative drug combinations and novel delivery strategies are crucial for overcoming these barriers. Polymeric micelles represent a promising approach for enhancing drug delivery to brain tumors. This study aimed to obtain micelles containing cannabidiol (CBD), celecoxib (CELE), and temozolomide (TMZ), as well as their combinations, and to verify their anti-glioma properties. The study involved optimizing the micelle composition, incorporating active ingredients, and assessing the temporal stability of the resulting nanocarriers under varying temperature conditions. The GBM cell line U-138 MG and astrocytoma cell line U-87 MG were used to evaluate the biologic effects of the tested micelles. Cytotoxicity was assessed using the MTT assay, and flow cytometry was used to analyze the effect of the micelles on apoptosis. Western blot analysis was employed to assess the impact of the tested nanoformulations on the Wnt/β-catenin signaling pathway. The optimized micelles demonstrated strong cytotoxic and proapoptotic effects, accompanied by attenuation of the Wnt/β-catenin pathway. These preliminary findings support the therapeutic potential of polymeric micelles for treating malignant gliomas; however, further in vitro and in vivo studies are required to confirm their clinical applicability. Full article

The production of quantum dots (QDs) has increased due to their wide variety of commercial products and applications. QDs can be dangerous in the environment because their small size can encourage their incorporation into living systems. In this project, ZnS and ZnSSe were synthesized under microwave irradiation, generating a water-stable nanomaterial. The bandgap energies calculated using the UV-Vis spectra were 3.81 and 3.86 eV for ZnS and ZnSSe QDs, respectively, indicating that the selenium worked as a dopant agent. The photoluminescence analysis shows narrow emission peaks, confirming a low size distribution, and the selenium doping generated a blue shift. The crystal size of both nanomaterials was around 7 nm. The cellular toxicity of these nanomaterials was evaluated using Chinese Hamster Ovary (CHO) Cells (a standard mammalian cell model). The results suggest that ZnS and ZnSSe QDs slightly affect the viability of CHO Cells, but Zn²⁺ decreases the viability at concentrations higher than 20 mg/L. The content of zinc inside cells (by ICP-OES) suggested that QDs can enter cells more easily than Zn²⁺. Therefore, the decrease in cell viability caused by Zn²⁺ outside the cells is likely due to its effect on cell membrane integrity, suggesting that these nanomaterials are less toxic than bulk materials. Full article

Fe-oxyhydroxides can incorporate toxic metals during the formation of mineral phases in soils and sediments, thereby potentially altering the environmental reactivity of metals and impacting the microbial communities. In this study, isothermal microcalorimetry has been used to monitor the metabolic activity of Pseudomonas putida KT2440 exposed to pure ferrihydrite and to Pb-, Cd-, and As-bearing ferrihydrites under oxygen-limited conditions. Calorimetric measurements of the integral heat released during the exponential growth were combined with the analysis of dissolved iron and heavy metals, as well as the glucose uptake, to understand how heavy metal incorporation modifies mineral reactivity and microbial heat output. Pure ferrihydrite decreased the integral heat by about 45%, primarily due to glucose and phosphate depletion, Fe(III) leaching, and mineral–cell aggregation. Heavy metal dopants were found to modulate nutrient availability, surface charge, and Fe solubilization, which, in turn, influenced the integral heat. Pb-Fh generated the highest ferrihydrite dissolution and metabolic heat, with a maximum effect at intermediate substitution levels. As-Fh induced moderate Fe release and metabolic activity, consistent with the enhanced phosphate sorption and lowered surface charge. Cd-bearing Fh showed minimal reactivity and yielded the lowest heat output. Microcalorimetry was proven useful for unraveling microbe–mineral interactions in complex contaminated environments. Full article

Regenerative medicine is increasingly leveraging the synergies between bioinspired conductive biomaterials and 3D/4D bioprinting to replicate the native electroactive and hierarchical microenvironments essential for functional tissue restoration. However, a critical gap remains in the intelligent integration of these technologies to achieve dynamic, responsive tissue regeneration. This review introduces a “bioinspired material–printing–function” triad framework to systematically synthesize recent advances in: (1) tunable conductive materials (polymers, carbon-based systems, metals, MXenes) designed to mimic the electrophysiological properties of native tissues; (2) advanced 3D/4D printing technologies (vat photopolymerization, extrusion, inkjet, and emerging modalities) enabling the fabrication of biomimetic architectures; and (3) functional applications in neural, cardiac, and musculoskeletal tissue engineering. We highlight how bioinspired conductive scaffolds enhance electrophysiological behaviors—emulating natural processes such as promoting axon regeneration cardiomyocyte synchronization, and osteogenic mineralization. Crucially, we identify multi-material 4D bioprinting as a transformative bioinspired approach to overcome conductivity–degradation trade-offs and enable shape-adaptive, smart scaffolds that dynamically respond to physiological cues, mirroring the adaptive nature of living tissues. This work provides the first roadmap toward intelligent electroactive regeneration, shifting the paradigm from static implants to dynamic, biomimetic bioelectronic microenvironments. Future translation will require leveraging AI-driven bioinspired design and organ-on-a-chip validation to address challenges in vascularization, biosafety, and clinical scalability. Full article

Dental caries is a major global health issue associated with biofilm formation by Streptococcus mutans (S. mutans). Conventional antimicrobials often fail to eliminate biofilms due to their structural resistance, highlighting the need for new strategies. This study investigated the antibacterial and antibiofilm effects of protamine peptides (PPs), which are cell-penetrating antimicrobial peptides derived from salmon protamine, alone and in combination with antimicrobial agents. Antimicrobial susceptibility was evaluated using alamarBlue^® and colony count assays, while biofilm formation was analyzed using crystal violet staining, confocal microscopy, and extracellular polysaccharide (EPS) quantification. PP exhibited moderate antibacterial activity but strongly suppressed EPS accumulation and biofilm development, leading to a flattened biofilm structure. Cotreatment with ε-poly-L-lysine (PL) significantly enhanced antibacterial and antibiofilm effects compared with either agent alone, whereas this effect was not observed with other cationic polymers. Fluorescence imaging revealed that PL promoted the intracellular localization of PP without increasing membrane damage, indicating a cooperative mechanism by which PL enhances membrane permeability and PP targets intracellular sites. These findings demonstrate that combining a cell-penetrating peptide with a membrane-active agent is a novel approach to overcome bacterial tolerance. The PP–PL combination effectively suppressed S. mutans growth and biofilm formation through dual action on membranes and EPS metabolism, offering a promising basis for the development of peptide-based preventive agents and biofilm-resistant dental materials. Full article

A facile and single-step synthesis of poly(L-Cysteine) (p(L-Cys)) particles through microemulsion polymerization using tetrakis(hydroxymethyl) phosphonium chloride (THPC) as crosslinker is accomplished for the first time. The L-Cys:THPC ratio in p(L-Cys) particles was calculated as 80:20% (by weight) with elemental analyses, and the generation of p(L-Cys) particles was confirmed. SEM imaging revealed a popcorn-like morphology of the p(L-Cys) particles with a 1–20 µm particle size range. The isoelectric point of p(L-Cys) particles was determined at pH 1.15 via zeta potential measurements. The hydrolytic degradation of p(L-Cys) particles was determined as about 85% within 3 h (by weight). The p(L-Cys) particles displayed excellent blood compatibility with a hemolysis % ratio of <2.3% and a blood clotting index of 95% at 1 mg/mL concentration. Moreover, cell compatibility tests up to 50 mg/mL against L929 fibroblast cells exhibited about 90% cell viability for p(L-Cys) particles versus 58% for L-Cys molecule. The antimicrobial efficacy of the L-Cys molecules was notably enhanced in p(L-Cys) particles, exhibiting a 5-fold reduction in minimal bactericidal concentration (MBC) values against E. coli (Gram-negative, ATCC 8739) and a 2-fold reduction against S. aureus (Gram-positive, ATCC 6538). Additionally, the antioxidant capacity of p(L-Cys) particles was retained somewhat, measured as 0.14 ± 0.01 µM versus 2.25 ± 0.03 µM Trolox equivalent/g for L-Cys. Therefore, p(L-Cys) particles are versatile and offer a unique avenue for immense biomedical use. Full article

Integrating antibacterial fabrics into wearable technology represents a transformative advancement in healthcare, fashion, and personal hygiene. Antibacterial fabrics, designed to inhibit microbial growth, are gaining prominence due to their potential to reduce infections, enhance durability, and maintain cleanliness in wearable devices. These fabrics offer effective antimicrobial properties while retaining comfort and functionality by incorporating nanotechnology and advanced materials, such as silver nanoparticles, zinc oxide, titanium dioxide, and graphene. The production techniques for antibacterial textiles range from chemical and physical surface modifications to biological treatments, each tailored to achieve long-lasting antibacterial performance while preserving fabric comfort and breathability. Advanced methods such as nanoparticle embedding, sol–gel coating, electrospinning, and green synthesis approaches have shown significant promise in enhancing antibacterial efficacy and material compatibility. Wearable technology, including fitness trackers, smart clothing, and medical monitoring devices, relies on prolonged skin contact, making the prevention of bacterial colonization essential for user safety and product longevity. Antibacterial fabrics address these concerns by reducing odor, preventing skin irritation, and minimizing the risk of infection, especially in medical applications such as wound dressings and patient monitoring systems. Despite their potential, integrating antibacterial fabrics into wearable technology presents several challenges. This review provides a comprehensive overview of the key antibacterial agents, the production strategies used to fabricate antibacterial textiles, and their emerging applications in wearable technologies. It also highlights the need for interdisciplinary research to overcome current limitations and promote the development of sustainable, safe, and functional antibacterial fabrics for next-generation wearable. Full article

This paper investigates the properties of zirconium oxide thin films deposited on Ti6Al4V and Si substrates via oblique angle deposition, using varying out-of-plane θ (15 to 85°) and in-plane Φ (0 and 180°) substrate orientations. ZrO₂ films have garnered significant interest due to their antibacterial properties and mechanical performance. The aim is to engineer surfaces capable of inhibiting bacterial growth while maintaining excellent mechanical integrity. The methodology combines experimental deposition by DC magnetron sputtering with multi-scale simulations using SRIM and SIMTRA. Structural analyses were conducted via X-ray diffraction, while microstructure and surface morphology were examined using scanning electron microscopy and atomic force microscopy. Nanoindentation tests were performed to assess hardness and elastic modulus. Results revealed that increasing the incidence angle α from 7 to 74° significantly affected surface morphology, microstructure, film thickness, and columnar tilt. The hardness and Young’s modulus of the films exceeded those of Ti6Al4V, for incidence angle α between 7 and 50°, but decreased with the increasing incidence angle α. Furthermore, the films exhibited strong antibacterial activity against Gram-positive pathogens (Staphylococcus aureus), particularly at the highest incidence angle α, with inhibition rates exceeding 90%. Full article

The growing need for self-powered Internet of Things networks has raised interest in converting abundant waste into reliable energy harvesters despite long-standing material and technology challenges. As demand for environmentally friendly self-powered IoT devices continues to rise, attention toward green waste as an eco-friendly energy source has strengthened. However, its direct utilisation in high-performance energy harvesters remains a significant challenge. Driven by the growing need for renewable sources, the triboelectric nanogenerator has emerged as an innovative technology for converting mechanical energy into electricity. In this work, the design, fabrication, and characterisation of a rotating triboelectric energy harvester as a prototype device employing date seed waste as the tribopositive layer are presented. The date seeds particles, measuring 1.2 to 2 mm, were pulverised using a grinder, mixed with epoxy resin, and subsequently applied to the grating-disc structure. The coated surface was machined on a lathe to provide a smooth surface facing. The performance of the prototype was evaluated through a series of experiments to examine the effects of rotational speed, the number of grating-disc structures, the epoxy mixing process, and the prototype’s influence on the primary system, as well as to determine the optimal power output. An increase in rotational speed (RPM) enhanced power generation. Furthermore, increasing the number of gratings and pre-mixing of epoxy with the biomaterial resulted in enhanced output power. Additionally, with 10 gratings, operating at 1500 rpm, and a 24 h pre-mixing method, the harvester achieved maximum voltage and power outputs of 129 volts and 1183 μW at 7 MΩ. Full article

Contemporary knee prostheses rely predominantly on a metal–polyethylene bearing couple, which—despite substantial advances in material engineering—continues to generate polymeric wear particles over time. While the local biological effects of polyethylene debris, such as inflammation and osteolysis, are well-characterised, their potential systemic implications remain insufficiently explored. In this review, we synthesise multidisciplinary evidence to evaluate the generation, biological behaviour, and systemic dissemination of polyethylene-derived nano- and microplastics (NMPs) released from knee prostheses. We also contextualise prosthetic wear within the broader toxicological framework of NMP exposure, highlighting translocation pathways, interactions with immune and metabolic systems, and potential multi-organ effects reported in recent experimental and clinical studies. Current findings suggest that prosthetic wear may represent an under-recognised internal source of NMP exposure, with possible implications for long-term patient health. A clearer understanding of the systemic behaviour of prosthetic-derived NMPs is essential to guide future biomonitoring studies, improve prosthetic materials, and support the development of safer, more biocompatible implant designs. Full article

We demonstrate that pulsed laser annealing induces plasmonic gold nanoparticles in ZnO thin films, monitored in real-time via pulse-by-pulse spectroscopy. Initially embedded gold nanoparticles (smaller than 5 nm) in sputtered ZnO films were annealed using 532 nm pulses from a Q-switched Nd:YAG laser while monitoring transmission spectra in situ. A plasmonic resonance dip emerged after ~100 pulses in the 530–550 nm region, progressively deepening with continued exposure. Remarkably, different incident energies converged to a thermodynamically stable optical state centered near 555 nm, indicating robust nanoparticle configurations. After several hundred laser shots, the process stabilized, producing larger nanoparticles (40–200 nm diameter) with significant surface protrusion. SEM analysis confirmed substantial gold nanoparticle growth. Theoretical modeling supports these observations, correlating spectral evolution with particle size and embedding depth. The protruding gold nanoparticles can be functionalized to detect specific biomolecules, offering significant advantages for biosensing applications. This approach offers superior spatial selectivity and real-time process monitoring compared to conventional thermal annealing, with potential for optimizing uniform nanoparticle distributions with pronounced plasmonic resonances for biosensing applications. Full article

The process of wound healing is intricate and regulated by a network of cellular, molecular, and biochemical pathways. Acute wounds progress via distinct phases of hemostasis, inflammation, proliferation, and remodeling. Chronic wounds frequently cease to heal and exhibit resistance to conventional therapies. These types of injuries are frequently attributed to diabetes, infection, or senescence. Existing therapies are constrained due to their ineffectiveness against bacteria, inability to promote regeneration, and inadequate control over medication release. Nanotechnology presents novel methods to overcome these challenges by providing multifunctional platforms that enable biological repair and medicinal delivery. Nanoparticles, which combat germs and modulate the immune system, in addition to being intelligent carriers that react to pH, oxidative stress, or enzymatic activity, provide targeted and adaptive wound therapy. Nanocomposite hydrogels are particularly advantageous as biointeractive dressings due to their ability to maintain wound moisture while facilitating regulated drug delivery. Recent advancements indicate their potential to aid in tissue regeneration, enhance therapy precision, and address issues related to safety and translation. Nanotechnology-based approaches, especially smart hydrogels, give significant promise to transform the future of wound care due to their flexibility, adaptability, and efficiency. Full article

This paper presents a theoretical and experimental investigation of the amplitude–frequency response of a triple-microcantilever system designed for real-time ultra-low mass detection. The present study focuses on the unfunctionalized configuration to clarify the intrinsic electromechanical behavior of this system. Starting with analytical expressions, output voltage amplitude–frequency responses are derived for a Wheatstone-bridge-based readout circuit and used to analyze the relationship between the resonant frequencies and mechanical amplitude–frequency responses of the three microcantilevers and the resulting electrical response. The extrema and zero-crossing points of the output voltage do not trivially coincide with the individual resonance peaks or their intersection points; this offers more freedom for defining strong detection criteria. A specialized experimental setup has been developed and used to measure the frequency response of a fabricated triple-microcantilever prototype; good agreement with the theoretical predictions has been found within the operating range. Initial humidification tests confirm the high sensitivity of the microsystem against small added masses, corresponding to an estimated detection limit on the order of 10⁻¹⁶ kg for the unfunctionalized device. In this way, the present work confirms the validity of the proposed triple-microcantilever configuration for ultra-low mass sensing and outlines its potential for future application in pathogen detection upon surface functionalization. Full article

Zinc oxide (ZnO) nanoparticles are widely used in cosmetics, coatings, and industrial formulations due to their UV-absorbing and antimicrobial properties; however, their increasing release into aquatic systems has raised concerns about potential ecological risks. This study evaluates the acute toxicity of pure and silver-doped ZnO (Ag-ZnO) nanoparticles using Artemia salina as a marine model organism. Nanoparticles were synthesized via a reflux-assisted method and characterized by UV–Vis spectroscopy, HRTEM, ED, FTIR, and EDX analyses, confirming a crystalline wurtzite structure, particle sizes of 10–30 nm, and successful incorporation of 5% Ag. Silver doping produced a slight blue shift in the absorption edge and minor lattice distortions, indicating modifications in the electronic structure. Toxicity assays revealed clear concentration- and time-dependent decreases in nauplii survival. Dose–response modeling showed LC₅₀ values of 358 ppm (24 h) and 64 ppm (48 h) for pure ZnO, whereas Ag-ZnO exhibited LC₅₀ values of 607 ppm (24 h) and 28 ppm (48 h). These results indicate that Ag doping does not enhance short-term toxicity but markedly increases toxicity after prolonged exposure. Overall, the findings highlight the need to consider both nanomaterial composition and exposure duration in ecotoxicological assessments and provide relevant data for evaluating the environmental impact of doped nanomaterials in marine systems. Full article