Search Results (2,133)

Water purification and treatment methods are becoming increasingly complex due to the use of new additives, solvents, pesticides, dyes, and other emerging pollutants in industry, agriculture, and households. Consequently, the search for new water treatment techniques and materials that can help reduce this environmental impact has become a major focus in the field of green chemistry. In this work, the photocatalytic degradation capacity of composites containing TiO₂ nanoparticles (TNPs) for the removal of organic pollutants in water was studied. The TNPs were immobilized in bio-based hydrogel microparticles, which were prepared using microfluidic techniques. The composition of the dispersed phase was optimized with a lab-on-a-chip device, resulting in composite microparticles with a narrow size distribution. UV–visible spectroscopy results indicated that increasing the concentration of TNPs in the hydrogel microparticles enhanced the photodegradation performance of the new composite. Remarkably, it was able to efficiently degrade nearly 90% of reference dyes after four adsorption–desorption cycles. Full article

Dynamic phase transition of natural gas hydrates confined within complex pore–throat structures is a key factor impacting the safe and efficient development of hydrate-bearing deposits. In this work, hydrate-bearing samples with varying saturation were first reconstructed with the proposed ice-seeding method using actual marine soil in hydrate-bearing sediments from the South China Sea. Dynamic evolution characteristics of hydrate formation in evolving porous media under different temperature and pressure conditions were analyzed in detail. Combined with high-resolution CT scanning, image processing, pore network extraction, and statistical analysis, the typical microscopic pore–throat structures of hydrate-bearing sediments were revealed, and the presence of nanopores was identified. Furthermore, highly controllable heterogeneous pore–throat structures were constructed for microfluidic chips by integrating stochastic modeling, equivalent modeling, and machine learning approaches. On this basis, a novel microfluidic testing method was developed for investigating the dynamic formation, dissociation, and phase transition characteristics of natural gas hydrates in complex pore structures by controlling the temperature. This study provides reliable data support and theoretical guidance for the productivity prediction of marine hydrate-bearing deposits. Full article

Biomimetic anisotropy is defined as intentionally engineered, nature-inspired directional differences in structure, chemistry, roughness, stiffness, or pore architecture. These directional differences lower transport resistance in one direction relative to the opposite direction, which results in rectified transport. In this review, anisotropy design is synthesized across surfaces, porous materials, and soft systems, with transport considered for droplets, low-surface-tension liquids, particles, and soft objects. Biological inspirations are summarized first, and the design lessons that can be transferred to engineered platforms are then extracted. Key anisotropic architectures are classified next, including ratchets and sawtooth textures, bristle- or setae-like fibrillar arrays, grooves and wedges, asymmetric pores and membranes, chemically patterned surfaces, and hierarchical micro–nano combinations. Practical fabrication methods and material choices are reviewed thereafter, spanning micro- and nanofabrication, additive manufacturing, coatings and surface modification, and responsive soft matter. The field is then organized mechanistically around how anisotropy generates directionality through contact-line pinning asymmetry, curvature-driven capillary pressure bias, compliance and elastocapillary coupling, and active rectification under oscillatory forcing. Finally, these mechanisms are connected to application needs in pump-free microfluidics and sampling, long-distance open transport, environmental water management, and fouling-prone self-cleaning systems. Throughout the review, design-to-function links are emphasized, and open challenges are highlighted, including durability under real fluids and contaminants as well as scalable manufacturing and integration. Full article

Extracellular vesicles (EVs) have emerged as promising tools for cancer diagnosis and therapy owing to their excellent biocompatibility, low immunogenicity, and ability to transport diverse bioactive molecules. This review summarizes recent advances in EVs research, focusing on isolation and detection technologies, their diagnostic and therapeutic applications in oncology, and the key challenges limiting clinical translation. Conventional EVs isolation methods, including ultracentrifugation, density-gradient centrifugation, and polymer-based precipitation, are discussed alongside emerging strategies such as immunoaffinity enrichment, microfluidic separation, lipid-mediated isolation, and thermophoretic enrichment, with comparative evaluation of their yield, purity, cost, and scalability. In cancer diagnosis, EV-associated biomolecules, such as miRNAs, mRNAs, proteins, and lncRNAs, show strong potential as liquid biopsy biomarkers for noninvasive early detection and dynamic disease monitoring. In therapeutic contexts, EVs serve as versatile carriers for gene molecules, chemotherapeutic agents, and small-molecule drugs, and can enhance immunotherapy and RNA-based treatments. Importantly, EVs released from metabolically active tissues, particularly skeletal muscle, contribute to systemic immune regulation and metabolic homeostasis, and their biogenesis and molecular cargo can be influenced by physical activity and exercise-related nutritional status. These insights highlight the need to integrate microengineering technologies, biomolecular profiling, standardized manufacturing systems, and lifestyle-related factors such as exercise and nutrition to accelerate the clinical translation of EV-based strategies in precision oncology and regenerative medicine. Full article

Microbially Induced Carbonate Precipitation (MICP) is a biochemical process that promotes the precipitation of calcium carbonate, mainly in the mineral form of calcite, using urease-producing bacteria. This method has numerous applications, particularly in the field of geotechnical engineering when it is adopted for soil improvement or for the consolidation of porous or cracked construction materials such as stone and concrete. One microfluidic platform made of polymethylmethacrylate (PMMA) was designed with multiple channels, and the minerals precipitated were visualized using an optical microscope. The precipitated mineral observed in all channels analyzed formed spherical mineral structures with a core and multiple external rings. The same spherical mineral structures were observed in the biocement layer precipitated on plates of the same material as that of the microfluidic platform and on limestone, following the same treatment protocol. SEM images of pieces of these layers, complemented with EDS and mineral analysis by XRD, have confirmed the existence of multiple layers of minerals with spherical structures, mainly vaterite, precipitated around a nucleation point. Overlapping minerals in both the confined microfluidic channels and the unconstrained plates indicate that overlap results from repeated injections rather than physical confinement. From the tests with the microfluidic devices, these studies revealed that crystallization depends on different factors, namely the size of the channels and the number of Sporosarcina pasteurii cells. The number of injections appeared to affect the number of rings precipitated around the inner core. Substrate effects on spatial distribution or adhesion may still exist but were not detectable in this study and require further investigation. The observation of similar mineralogical structures in both the microfluidic devices and the plates, particularly the limestone, demonstrates that microfluidic systems are effective tools for small-scale visualization of geological processes. Full article

Clove (Syzygium aromaticum (L.) Merr. & L.M. Perry) essential oil (EO)-based nanoemulsions may have a promising future in eco-friendly herbicide development. Clove EO was found to have a high eugenol content of 87.27%. Organic-solvent-free nanoemulsions using clove EO as a bioactive ingredient were fabricated using ultrasonication and microfluidization emulsification methods. Fourier-transform infrared spectroscopy confirmed that both emulsification methods did not affect the EO components. The droplet size of optimized nanoemulsions was determined using dynamic light scattering. The smallest size of 66.9 nm was obtained by microfluidization at 20,000 psi and eight passes. Additionally, the smallest droplet size for a sonicated nanoemulsion was 103.9 nm, obtained by ultrasonication at 20% for 6 min. Transmission electron microscopy confirmed the droplet sizes of both optimized nanoemulsions. In a storage test, both optimized nanoemulsions were stored at 4 °C for at least four weeks. Finally, both nanoemulsions were evaluated on pre-emergence herbicidal activities against Echinochloa crus-galli. The results showed that both nanoemulsions inhibited E. crus-galli germination and seedling growth, and additionally, inhibited seed imbibition and α-amylase activity. Micro-morphological and ultrastructural analysis was observed using a scanning electron microscope and an energy dispersive X-ray spectrometer (SEM-EDS). SEM-EDS micrographs of the treated seeds showed that the seed structure was damaged, especially the endosperm, leading to the inhibition of seed germination. Full article

Lipid nanoparticles (LNPs) have been widely utilized as carriers for nucleic acid drug delivery; however, their inherent heterogeneity impedes the accurate characterization of physicochemical and biological properties. Conventional analytical methods are inherently limited in resolving such heterogeneity. This study employed sucrose density gradient centrifugation (S-DGC) to separate LNP subpopulations of varying densities. It investigated the effects of lipid formulation parameters—including nitrogen-to-phosphorus (N/P) ratio, lipid composition, polyethylene glycol (PEG) concentration—and microfluidic preparation conditions (flow rate) on LNP heterogeneity and biological functionality. Formulation stability was assessed via freeze–thaw testing. The results demonstrated that S-DGC could effectively separate LNP subpopulations with divergent densities and physicochemical characteristics. Changes in the N/P ratio and lipid composition significantly modulate subphase distribution and properties. When cholesterol (Chol) and distearoylphosphatidylcholine (DSPC) are absent from the formulation, LNPs aggregate in the low-density layer (0–10% sucrose density layer). The concentration of PEGylated lipids serves as a critical regulatory factor. When the concentration increased from 0.5% to 2.5%, the LNP particle size decreased from approximately 202 nm to 118.7 nm. Furthermore, the S-DGC profile indicates that LNP transitions from an aggregated low-density distribution to a uniformly dense subpopulation concentrated within the 0–20% sucrose layer, where transfection efficiency is optimal. In freeze–thaw stability assessment, unprotected LNP exhibited a drastic decline in encapsulation efficiency to 5.3% after three freeze–thaw cycles at −80 °C. The S-DGC diagram revealed aggregation in the 20–30% high-density region. However, adding 5% sucrose maintained encapsulation efficiency above 96%. This study confirms that the S-DGC analytical platform serves as a potent tool for resolving LNP heterogeneity and correlating formulation structure with function. Based on these findings, this study contends that during the early prescription development of LNP-based nucleic acid therapeutics, formulation screening should not be confined to meeting overall particle size and encapsulation rate targets. Instead, S-DGC can be employed to proactively identify and minimize ineffective subpopulations (such as particles distributed in extremely high or low density zones), thereby enhancing product quality uniformity and predictability from the outset of R&D. Full article

Tumor Mutational Burden (TMB) is a critical biomarker used to determine patient eligibility for immunotherapy with immune checkpoint inhibitors. However, its gold-standard assessment via whole exome sequencing is limited by high costs, technical complexity, and lengthy processing times. To address these challenges, we investigated whether Ultra-High-Frequency (UHF) electromagnetic wave sensing could serve as an alternative method for evaluating TMB. We analyzed the dielectrophoresis crossover frequency spectrum and corresponding electromagnetic signature (EMS) of cancer cells using a lab-on-a-chip biosensor that integrates microfluidics with dielectrophoresis-based electro-manipulation. Across seven solid tumor cell lines exhibiting diverse TMB levels, EMS exhibited an upward shift correlated with higher TMB, suggesting a relationship between mutational load and electromagnetic behavior. To further explore this connection, we artificially increased the somatic variant burden by exposing cells to the mutagen N-ethyl-N-nitrosourea (ENU). EMS measurements reliably detected the induced increase in variant load in ENU-treated cells. Overall, these findings demonstrate that EMS can detect both intrinsic TMB differences and experimentally induced increases in mutational burden, enabling refined categorization of cancer cells. Although further validation is required, this work lays the foundation for developing complementary, rapid, and accessible tools to support cancer cell stratification and guide immunotherapy decision-making. Full article

Three-dimensional (3D) cultured cells can mimic the in vivo tumor microenvironment more accurately than conventional monolayer cultures. Therefore, they are essential in cancer research and drug discovery. However, high-sensitivity fluorescence imaging of 3D spheroids remains challenging owing to their limited contact with the observation surface and the low penetration depth of total internal reflection fluorescence microscopy (TIRFM). In this study, we developed a microfluidic device equipped with a water-driven balloon actuator that enables the hydrostatic compression of 3D-cultured spheroids. This system gently presses spheroids against a glass surface, significantly enhancing the contact area and improving TIRFM and epifluorescence imaging quality, with more evident improvement observed in TIRFM. Our results show that hydrostatic compression markedly enhances optical accessibility in spheroids while preserving cell viability and structural integrity. The method is designed to complement volumetric imaging techniques, including confocal and light-sheet microscopy, by enabling high-contrast visualization of cell–surface molecular dynamics. Although the current system focuses on surface accessibility, future studies will incorporate rotational mechanisms and automated pressure control to facilitate multi-angle, high-throughput imaging. This platform offers a promising strategy for the dynamic observation of cell–surface interactions in living 3D systems. Full article

Microfluidics-based preparation methods for cell-laden hydrogel microspheres are well-suited for large-scale comparative analysis of single or few cells. However, in existing studies, the preparation of cell-laden hydrogel microspheres and the cell culture process are typically separated, requiring the fabricated microspheres to be eluted and transferred from the preparation device to cell culture dishes or plates for cultivation. This transfer process can easily compromise sterility, while conventional cell culture methods consume more reagents and cause microsphere stacking, hindering single-cell observation and analysis. To address these issues, this paper presents an integrated microfluidic chip that sequentially enables droplet generation with cell encapsulation, gel droplet solidification, hydrogel microsphere trapping, and microsphere-based cell culture and analysis, facilitating the cultivation and observation of single or small numbers of cells. Integrating cell-laden microsphere preparation and 3D cell culture within a sealed chip structure reduces contamination risks associated with cell transfer, enables automation of multiple cell analysis workflows, and minimizes reagent and sample consumption. Using polydimethylsiloxane (PDMS) with good gas permeability and processability as the chip material, biocompatible fluorinated oil was selected as the oil phase for microsphere preparation. A mild sodium alginate-calcium ion gelation system was employed, where calcium ions were released under acidic conditions after droplet generation to trigger solidification, yielding uniform hydrogel microspheres. Under optimized conditions, the single-cell encapsulation efficiency for test samples of human myeloid leukemia cells (K562) was 33.8% ± 1.8%, with a size uniformity coefficient of variation (CV) reaching 3.85%. Cells encapsulated within hydrogel microspheres were cultured in 286 on-chip independent cell culture chambers, achieving >95% viability after 24 h. Full article

Water contamination from diverse chemical pollutants has become a major environmental concern, demanding innovative and efficient remediation strategies. In this study, a Mg/Fe-layered double hydroxide (LDH) silica-magnetite hybrid composite was synthesized using a laser-cut microfluidic device to achieve controlled mixing and uniform particle formation. The obtained hybrid composite was further characterized by XRD, SEM, FT-IR, RAMAN, and DLS, confirming a structurally integrated LDH-silica-Fe₃O₄ hybrid, stabilized by ionic interactions, hydrogen bonds, and Si-O-Mg interactions. Moreover, biological assays confirmed that the developed material does not exhibit significant cytotoxicity and is potentially safe for environmental applications. Further, the adsorption performance was determined by treating surface water samples containing a mixture of pesticides with the composite material. After magnetic separation, the samples were analyzed by FT-ICR HR-MS, which enabled the detection and discrimination of ions with very close m/z values. The obtained results demonstrate a significant water decontamination capacity for multiple pesticides and facile water removal via magnetic separation, suggesting that these materials and the fast FT-ICR screening method are prospective, practical solutions for environmental protection of water bodies. Full article

This paper investigates a novel optical method that uses a high-responsivity a-Si:H photodiode for label-free detection of luminescence from HeLa cervical cancer cells excited by a blue LED. We examine the energy distribution of the energy-gap density of states (DOS) from the photodiode’s long-time transient current, which shows exponential decay kinetics in the HeLa cell reaction. We analysed the transient response of a-Si:H p-i-n photodiode upon the illumination of the analyte with a pulsed blue LED light to better understand the HeLa cells activity and the fundamental defect kinetics processes in the a-Si:H material. Results suggest that the characteristic very low-level, time-varying light response of HeLa cells is due to chemiluminescence within cells, resulting from the reaction between nitric oxide (NO) and hydrogen peroxide (H₂O₂). Given the low signal intensity and noise, we applied a Savitzky–Golay (SG) filter to post-process the data. By reducing noise without attenuating chemiluminescent peaks, the Savitzky–Golay filter enabled accurate, reproducible quantification of the photocurrent response, reflecting the kinetics of cellular reactions. Further studies and more precise measurement instruments are needed for this real-time, label-free, non-destructive method, which applies SG-filtered signal processing to microfluidic optical biosensors. Full article

In this research, an innovative scheme to generate heterogeneous acoustofluidic distributions in various pseudo-Sierpiński-carpet-shaped chambers with different filling fractions and cross-sectional configurations has been proposed and calculated for topographical manipulation of large-scale micro-particles. All of the structural components positioned in the pseudo-fractal chambers are symmetrically distributed in space, and all ultrasonic radiation surfaces hold the unified settings of input frequency point, oscillation amplitude, and initial phase distribution along their respective normal directions. A large number of fascinating acoustofluidic patterns can be generated in the originally-static pseudo-Sierpiński-carpet-shaped chambers at different recursion levels without complicated vibration parameter modulation. The simulation results of acoustofluidic distributions and particle motion trajectories under different radiation surface arrangements further demonstrate the manipulation performance of these specially designed devices, and indicate that controllable spatial partitioning and intensity modulation of the acoustofluidic field can be achieved by adjusting the hierarchical order, cross-sectional configuration and combination mode of the radiation surfaces. Unlike the existing device construction method of miniaturized microfluidic systems, the artificial introduction of fractal elements like Sierpiński carpet/triangle, Koch snowflake, Mandelbrot set, Pythagoras tree, etc., can provide extraordinary perspectives and expand the application range of the acoustofluidic effect, which also makes ultrasonic micro/nano-scale manipulation technology more abundant and diversified. This exploratory research indicates the potential possibility of applying fractal structures as alternative component parts to purposefully customize acoustofluidic distributions for the further research of patterned manipulation of bio-organisms and navigation of micro-robot swarms in brand new ways that cannot be achieved through traditional methods. Full article

Dynamic monitoring of hemostatic equilibrium is indispensable for clinical safety in high-risk scenarios, while current clinical methods are limited by sample volume, detection speed, and physiological relevance. These shortcomings underscore the demand for novel sensing platforms. Optical biosensors, leveraging label-free detection, rapid response, and multi-level characterization, could serve as a transformative solution for decentralized and point-of-care monitoring. This review systematically summarizes advances in optical coagulation testing, encompassing light transmission aggregometry, laser speckle rheology, optical coherence tomography/elastography, optic–acoustic coupled methods, and fluorescence biosensing. These technologies complementarily capture structural and mechanical and some molecular and cellular dynamics of coagulation, bridging gaps in traditional assays. Despite promising preclinical and clinical correlations, translation barriers persist in lack of standardization of metrics, interference mitigation, and multi-center validation in diverse patient cohorts. Future development of optical biosensing platforms for coagulation testing should focus on modular integration, AI-aided interference correction, and microfluidic miniaturization to realize actionable, real-time coagulation assessment. Optical biosensors hold unparalleled potential to transform hemostatic monitoring from static endpoint testing to dynamic, interpretable evaluation, guiding personalized clinical decisions. Full article

Background: Prostate cancer is a leading malignancy among males, and conventional chemotherapy is often limited by insufficient tumor selectivity and systemic toxicity. Prostate-specific membrane antigen (PSMA), which is highly expressed on prostate cancer cells, represents a promising target for precision drug delivery. In this study, we developed a folate-modified, PSMA-targeting nanoliposome loaded with docetaxel (DFL) to enhance tumor specificity and therapeutic efficacy. Methods: DFL was prepared using a thin-film hydration–sonication method and characterized through physicochemical analyses. Cellular uptake and cytotoxicity were evaluated in PSMA-high LNCaP cells, with PSMA knockdown used to assess target-dependent internalization. Antitumor efficacy was examined with a microfluidic system and LNCaP xenograft nude mice, and safety was evaluated by measuring hepatic and renal biomarkers and performing histopathological analysis of major organs. Results: DFL demonstrated favorable physicochemical properties and significantly enhanced cellular uptake and cytotoxicity in LNCaP cells relative to control formulations. PSMA knockdown markedly attenuated cellular sensitivity to DFL, confirming PSMA-dependent internalization. A 3D microfluidic perfusion platform further corroborated robust and selective DFL uptake under dynamic flow conditions, thereby strengthening the translational relevance of the targeting effect beyond static cultures. In vivo, DFL substantially inhibited tumor progression in LNCaP xenograft models, reducing both tumor volume and weight by more than 50%. TUNEL assays showed increased apoptosis, and immunohistochemistry revealed reduced Ki-67 expression with concomitant upregulation of Caspase-3. No significant alterations in hepatic or renal biomarkers were observed, and histopathological evaluation demonstrated no treatment-associated lesions in major organs. Conclusions: A folate-modified, PSMA-targeting docetaxel nanoliposome was successfully developed, demonstrating enhanced tumor-specific drug delivery and improved antitumor activity with favorable biocompatibility in preclinical models. DFL represents a promising nanomedicine strategy for the precision chemotherapy of prostate cancer. Full article