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Polydimethylsiloxane (PDMS), a fundamental material in the fabrication of microfluidic devices, suffers from nonspecific adsorption of biological samples due to its hydrophobic nature. Herein, by employing a radiation-induced grafting strategy to introduce hydrophilic functional groups onto the PDMS surface, a significant improvement in hydrophilicity is achieved, leading to a notable reduction in the contact angle by up to ∼90° and improvement of antifouling performance against biological samples. Effects between monomer concentration, grafting efficiency, and mechanical integrity are balanced to optimize the grafting process, achieving promised hydrophilicity enhancement while the mechanical properties are not degraded. The content of carboxyl groups exposed on the surface of grafted PDMS was computationally analyzed using MD simulations, which revealed the key role of carboxyl groups in the wettability of the PDMS surface. Our study extensively showcases the effective grafting of acrylic acid onto PDMS, which is characterized by diverse grafting rates. Remarkably, the hydrophilic modification is stable over time compared to conventional plasma treatment, offering a more reliable and enduring strategy, and making it a valuable enhancement for PDMS chips with extensive applications. [ABSTRACT FROM AUTHOR]

A nonlinear model, based on the area difference elasticity theory, has been developed to predict the sequence of stomatocyte–discocyte–echinocyte transformation in red blood cells. This model coarsely grains the cell membrane into a triangular network, accounting for the shear deformation of membrane skeleton, the area dilation, volume variation, bending deformation, and area difference deformation of lipid bilayer. It exhibits linear behavior under small deformations and transits to nonlinear behavior under large deformations, mirroring the biomechanical response of the cell that is susceptible to small deformations but significantly resists large deformations. The model parameters are calibrated by determining the biconcave equilibrium shape from an ellipsoidal stress-free configuration. After calibration, the model is utilized to predict the stomatocyte–discocyte–echinocyte transformation and is compared with the previously published experimental observations and the numerical results. It has been shown that the equilibrium shapes of a red blood cell are achieved in a self-equilibrium of spring lengths, as well as the balance between the triangle areas and surface area, and the interplay among dihedral curvature and area differences. The nonlinear model is believed to be capable of predicting the deformation behavior of red blood cells in diverse shape-transforming scenarios, such as in microvascular circulation and microfluidic devices. [ABSTRACT FROM AUTHOR]

Simple and stable generation of monodispersed droplets with volume from picolitre to nanoliter is one of the key factors in high-throughput quantitative microreactors for chemical and biomedical applications. In this work, an efficient method that could realize simple manipulating microflow with a broad operation window for preparing monodispersed droplets with controllable diameter is developed. The microfluidic device is constructed by inserting a capillary with an oblique angle (α) into the continuous phase, named a floating capillary-based open microfluidic device (FCOMD). The transition of droplet-generating mode between dripping and jetting can be achieved by changing capillary number and α. A computational model based on the volume-of-fluid/continuum-surface-force method to explain the controllability of α on the droplet formation regime and droplet breakage, verifying the synergistic effect of ΔP and Fb, facilitates the droplet pinching. A descending order of Pn of capillary with different α is that 45° > 30° > 15° > 60° > 75°, leading to the same order of generated droplet's D. When compared with the traditional capillary co-flow device, the generating throughput of the integrated FCOMD obtained by integrating different numbers of capillaries is at least ten times. Moreover, water in oil, oil in water double-emulsion, colloidal dispersed droplets, and liquid crystal droplets with diameters ranging from 25 to 800 μm are prepared on-demand by the FCOMD, indicating the universality of the microfluidic device. Thus, the FCOMD shows the features of simplicity, practicability, and flexibility, offering valuable guidance for generating controllable droplets with wide size change and showing a great potential application in material science, foods, pharmaceuticals, and cosmetics. [ABSTRACT FROM AUTHOR]

Unlike the conventional electroosmotic flow (EOF) driven by direct current and alternating current electric fields, this study investigates the pulse EOF of Newtonian fluids through a parallel plate microchannel actuated by pulse electric fields. Specifically, the pulses considered encompass triangular and half-sinusoidal pulse waves. By applying the Laplace transform method and the residual theorem, the analytical solutions for the velocity and volumetric flow rate of the pulse EOF associated with these two pulse waves are derived, respectively. The influence of pulse width a ¯ and electrokinetic width K on velocity is further considered, while the volumetric flow rate as a function of time t ¯ and electrokinetic width K is examined separately. A comparison of the volumetric flow rates related to these two pulse waves under varying parameters is also conducted. The research findings indicate that irrespective of the pulse wave, a broader pulse width results in a prolonged period and increased amplitude of the velocity profile. Elevating the electrokinetic width yields higher near-wall velocities, with negligible effect on near-center velocities. It is noteworthy that regardless of the electrokinetic width, the near-wall velocity exceeds that of the near-center during the first half-cycle, while the situation reverses during the second half-cycle. The volumetric flow rate varies periodically with time, initially surging rapidly with electrokinetic width before gradually stabilizing at a constant level. More interestingly, independent of pulse width and electrokinetic width, the volumetric flow rates linked to the half-sinusoidal pulse wave consistently surpass those of the triangular pulse wave. For any pulse width, the volumetric flow rates corresponding to the two pulse waves grow with higher electrokinetic widths, especially prominent at alternating intervals of the two half-cycles within a complete cycle. These findings have important implications for improving the design and optimization of microfluidic devices in engineering and biomedical applications utilizing pulse EOF. [ABSTRACT FROM AUTHOR]

The power-law fluid flow in tree-like self-similar branching networks is prevalent throughout the natural world and also finds numerous applications in technology such as oil recovery and microfluidic devices. We investigate analysis of optimal power-law fluid flow conditions and the optimal structures within tree-like branching networks, focusing on maximizing flow conductance under the constraint of the network tube's volume and the surface area. The study considered fully developed laminar power-law fluid flow regimes without considering any losses in the network system. A key observation was the sensitivity of the dimensionless effective flow conductance to the network's geometrical parameters. We found that the maximum flow conductance occurs when a dimensionless radius ratio β ∗ satisfies the equation β ∗ = N − 1 / 3 and β ∗ = N − (n + 1) / (3 n + 2) under constrained tube-volume and surface-area, respectively. Here, N represents the bifurcation number of branches splitting at each junction, and n is the fluid power-law index. We further find that this optimal condition occurs when pressure drops are equipartition across each branching level. We validated our results with various experimental results and theories under limiting conditions. Further, Hess–Murray's law is justified and extended for the shear-thinning and shear-thickening fluid flows for an arbitrary number of branches N. Further, in this study, we also derive the relationships between the geometrical and flow characteristics of the parent and daughter tubes as well as the generalized scaling laws at the optimal conditions for the other essential parameters such as tube-wall stresses, length ratios, mean velocities, tube-volume, and surface-area of the tube distributing within the networks. We find that the fluid power-law index n does not influence the constrained tube-volume scaling at the optimal conditions; however, the scaling laws vary with n under the constrained tube's surface area. These findings offer valuable design principles for developing efficient transport and flow systems. [ABSTRACT FROM AUTHOR]

3D printing techniques allow for the precise placement of living cells, biological substances, and biochemical components, establishing themselves as a promising approach in bioengineering. Recently, 3D printing has been applied to develop human-relevant in vitro cancer models with highly controlled complexity and as a potential method for drug screening and disease modeling. Compared to 2D culture, 3D-printed in vitro cancer models more closely replicate the in vivo microenvironment. Additionally, they offer a reduction in the complexity and ethical issues associated with using in vivo animal models. This focused review discusses the relevance of 3D printing technologies and the applied cells and materials used in cutting-edge in vitro cancer models and microfluidic device systems. Future prospective solutions were discussed to establish 3D-printed in vitro models as reliable tools for drug screening and understanding cancer disease mechanisms. [ABSTRACT FROM AUTHOR]

Purpose: Ultrasmall silver sulfide nanoparticles (Ag2S-NP) have been identified as promising contrast agents for a number of modalities and in particular for dual-energy mammography. These Ag2S-NP have demonstrated marked advantages over clinically available agents with the ability to generate higher contrast with high biocompatibility. However, current synthesis methods for inorganic nanoparticles are low-throughput and highly time-intensive, limiting the possibility of large animal studies or eventual clinical use of this potential imaging agent. Methods: We herein report the use of a scalable silicon microfluidic system (SSMS) for the large-scale synthesis of Ag2S-NP. Ag2S-NP produced using this system were compared to bulk synthesis and a commercially available microfluidic device through characterization, contrast generation, in vivo imaging, and clearance profiles. Results: Using SSMS chips with 1 channel, 10 parallelized channels, and 256 parallelized channels, we determined that the Ag2S-NP produced were of similar quality as measured by core size, concentration, UV–visible spectrometry, and in vitro contrast generation. Moreover, by combining parallelized chips with increasing reagent concentration, we were able to increase output by an overall factor of 5,100. We also found that in vivo imaging contrast generation was consistent across synthesis methods and confirmed renal clearance of the ultrasmall nanoparticles. Finally, we found best-in-class clearance of the Ag2S-NP occurred within 24 h. Conclusions: These studies have identified a promising method for the large-scale production of Ag2S-NP, paving the way for eventual clinical translation. [ABSTRACT FROM AUTHOR]

Microparticle sorting is crucial for applications in biomedicine, environmental monitoring, and biochip technology. However, traditional optical sorting methods often rely on external equipment, such as microfluidic devices. In this Letter, we proposed a phase-gradient force-based optical array sorting (POAS) scheme, which achieves the accurate transporting and sorting of the particles by regulating the phase-gradient force based on the physical characteristics of the particles. The method combines the function of particle transporting and sorting, eliminating the need for external auxiliary equipment. Based on the POAS scheme, we used the complex amplitude beam shaping algorithms to design a 1 × 2 array sorting beam with the controllable phase-gradient forces. The array sorting beam was used to experimentally sort two kinds of particles with different sizes, and the particles are first transported and then precisely sorted at the designated sorting nodes. All the parameters of the sorting beam were adjustable, which greatly enhances the flexibility and scalability of the optical sorting technology. This study provides an alternative scheme for the high-throughput particle sorting, which can be easily integrated into the optical sorting chips for applications in medical detection and drug delivery. [ABSTRACT FROM AUTHOR]

Infrared spectro-microscopy is a powerful technique for analysing chemical maps of cells and tissues for biomedical and clinical applications, yet the strong water absorption in the mid-infrared region is a challenge to overcome, as it overlaps with the spectral fingerprints of biological components. Microfluidic chips offer ultimate control over the water layer thickness and are increasingly used in infrared spectromicroscopy. However, the actual impact of the water layer thickness on the instrument's performance is often left to the experimentalist's intuition and the peculiarities of specific instruments. Aiming to experimentally test the amount of absorption introduced by water with varying layer thicknesses, we fabricated a set of microfluidic devices with three controlled chamber thicknesses, each comprising a simple test pattern made of a wellknown photoresist SU-8. We employed two infrared spectro-microscopy methods for measurements. The first method involves using a standard FTIR microscope with a benchtop infrared light source. The second method is a quantum infrared microscopy technique, where infrared imaging is achieved by detecting correlated photons in the visible range. We demonstrated that both methods enable the measurement of the absorption spectrum in the mid-IR region, even in the presence of up to a 30 µmthick water layer on top of a sample pattern. Additionally, the Q-IR technique offers practical advantages over synchrotron-based FTIR, such as reduced complexity, cost, and ease of operation. [ABSTRACT FROM AUTHOR]

Colistin is essential for treating multidrug-resistant Gram-negative bacterial infections but has significant nephrotoxic side effects. Traditional approaches for studying colistin's nephrotoxicity are challenged by the rapid metabolism of its prodrug, colistin methanesulfonate and the difficulty of obtaining adequate plasma from critically ill patients. To address these challenges, we developed the Spheroid Nephrotoxicity Assessing Platform (SNAP), a microfluidic device that efficiently detects colistin-induced toxicity in renal proximal tubular epithelial cell (RPTEC) spheroids within 48 hours using just 200 µL of patient plasma. Our findings demonstrate that SNAP not only promotes higher expression of kidney-specific markers aquaporin-1 (AQP1) and low-density lipoprotein receptor-related protein 2 (LRP2) compared to traditional two-dimensional (2D) cultures, but also exhibits increased sensitivity to colistin, with significant toxicity detected at concentrations of 50 μg ml-1 and above. Notably, SNAP's non-invasive method did not identify nephrotoxicity in plasma from healthy donors, thereby confirming its physiological relevance and showcasing superior sensitivity over 2D cultures, which yielded false-positive results. In clinical validation, SNAP accurately identified patients at risk of colistin-induced nephrotoxicity with 100% accuracy for both early and late onset and demonstrated a 75% accuracy rate in predicting the non-occurrence of nephrotoxicity. These results underline the potential of SNAP in personalized medicine, offering a noninvasive, precise and efficient tool for the assessment of antibiotic-induced nephrotoxicity, thus enhancing the safety and efficacy of treatments against resistant bacterial infections. [ABSTRACT FROM AUTHOR]

Point-of-care (PoC) devices offer a promising solution for fast, portable, and easy-to-use diagnostics. These characteristics are particularly relevant in agrifood fields like viticulture where the early detection of plant stresses is crucial to crop yield. Microfluidics, with its low reagent volume requirements, is well-suited for such applications. Self-driven microfluidic devices, which rely on capillary forces for fluid motion, offer an attractive alternative by eliminating the need for external pumps and complex fluid control systems. However, traditional microfluidic prototyping materials like polydimethylsiloxane (PDMS) present challenges due to their hydrophobic nature. This paper presents the development of a reusable, portable, capillary-driven microfluidic platform based on a PDMS-PEG (polyethylene glycol) copolymer designed for the rapid low-cost detection of abscisic acid (ABA), a key biomarker for the onset of ripening of non-climacteric fruits and drought stress in vines. By employing passive fluid transport mechanisms, such as capillary-driven sequential flow, this platform enables precise biological and chemical screenings while maintaining portability and ease of use. A simplified field-ready sample processing method is used to prepare the grapes for analysis. [ABSTRACT FROM AUTHOR]

Background: The challenges associated with traditional drug screening, such as high costs and long screening times, have led to an increase in the use of single-cell isolation technologies. Small sample volumes are required for high-throughput, cell-based assays to reduce assay costs and enable rapid sample processing. Using microfluidic chips, single-cell analysis can be conducted more effectively, requiring fewer reagents and maintaining biocompatibility. Due to the chip's ability to manipulate small volumes of fluid, high-throughput screening assays can be developed that are both miniaturized and automated. In the present study, we employ microfluidic chips for drug screening in chronic myeloid leukemia. This study aimed to establish a robust methodology integrating diverse assays, providing a holistic understanding of drug response. Material and methods: Herein, we have used a chronic myeloid leukemia derived cell line (K562) for drug screening with an innovative microfluidic-based drug screening approach to investigate the efficacy of imatinib in K562 cells. Cell viability was assessed using MTT assay. Apoptosis was measured using Annexin/PI staining by flow cytometry. Results: Significant increased apoptosis was seen in K562 cells treated with imatinib in the microfluidic device compared to cells treated with imatinib in 24- and 96-well plates. Moreover, in the microfluidic chip, drug screening time was reduced from 48 hours to 24 hours. Conclusion: Compared to traditional approaches, microfluidic-based drug screening efficiently evaluates the efficacy of imatinib in K562 cells. This approach is promising for drug discovery and treatment optimization, as it increases sensitivity and streamlines the screening process. [ABSTRACT FROM AUTHOR]

In this work, we have investigated the influence of several key parameters on CFSE with the help of CFD simulation and experiment, thus achieving precise CFSE droplet generation. As a result, we have accurately generated multi-volume droplets and applied them in quantifying PCR samples with concentrations from 10 copies/μL to 20,000 copies/μL. With the flexible multi-volume droplet generation capability, the CFSE device has essential application prospects in the ddPCR field, which can achieve an ultra-wide dynamic range of nucleic acid molecular quantitative analysis. [Display omitted] The co-flow step emulsification (CFSE) is very sensitive to the two-phase fluid interfaces, we conjecture that the CFSE hydrodynamic model depends on several key factors and the droplet generation process can be precisely controlled, thus to obtain droplet emulsions with the "ultra-high volume fraction of inner-phase" and "flexible droplet size" characteristics. The resulting droplets are expected to be applied to droplet digital PCR (ddPCR) with "high information density" and "wide dynamic range" advances. By combining numerical simulation and fluid dynamics experiments, we have investigated the crucial parameters affecting the CFSE two-phase interface and finally achieved the prediction and guidance for CFSE droplet production. With the help of the CFSE device, multivolume droplet populations were produced on demand. Then, ddPCR tests were performed with DNA concentrations from 10 copies/μL to 20,000 copies/μL. The CFSE device owns an ultra-wide dynamic range (up to 5 orders of magnitude), showing excellent quantification ability of nucleic acid targets. [ABSTRACT FROM AUTHOR]

Measuring virus in biofluids is complicated by confounding biomolecules coisolated with viral nucleic acids. To address this, we developed an affinity-based microfluidic device for specific capture of intact severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Our approach used an engineered angiotensin-converting enzyme 2 to capture intact virus from plasma and other complex biofluids. Our device leverages a staggered herringbone pattern, nanoparticle surface coating, and processing conditions to achieve detection of as few as 3 viral copies per milliliter. We further validated our microfluidic assay on 103 plasma, 36 saliva, and 29 stool samples collected from unique patients with COVID-19, showing SARS-CoV-2 detection in 72% of plasma samples. Longitudinal monitoring in the plasma revealed our device's capacity for ultrasensitive detection of active viral infections over time. Our technology can be adapted to target other viruses using relevant cell entry molecules for affinity capture. This versatility underscores the potential for widespread application in viral load monitoring and disease management. [ABSTRACT FROM AUTHOR]

The "Lab on a Chip" journal, published by The Royal Society of Chemistry, features various papers on devices and applications at the micro- and nanoscale. The latest issue includes articles on topics such as acoustic micromixers, ultrasound maintenance of sperm motility, textile-based microfluidics for wearable devices, and telomerase activity detection at the single-cell level. The journal aims to connect the world with the chemical sciences and reinvest profits back into the chemistry community. [Extracted from the article]

Tumor organoids present a challenge in drug screening due to their considerable heterogeneity in morphology and size. To address this issue, we proposed a portable microfluidic device that employs image processing algorithms for specific target organoid recognition and microvalve-controlled deflection for sorting and collection. This morphology-activated organoid sorting system offers numerous advantages, such as automated classification, portability, low cost, label-free sample preparation, and gentle handling of organoids. We conducted classification experiments using polystyrene beads, F9 tumoroids and patient-derived tumor organoids, achieving organoid separation efficiency exceeding 88%, purity surpassing 91%, viability exceeding 97% and classification throughput of 800 per hour, thereby meeting the demands of clinical organoid medicine. [ABSTRACT FROM AUTHOR]

Despite considerable animal sacrifices and investments, drug development often falters in clinical trials due to species differences. To address this issue, specific in vitro models, such as organ-on-a-chip technology using human cells in microfluidic devices, are recognized as promising alternatives. Among the various organs, the human small intestine plays a pivotal role in drug development, particularly in the assessment of digestion and nutrient absorption. However, current intestine-on-a-chip devices struggle to accurately replicate the complex 3D tubular structures of the human small intestine, particularly when it comes to integrating a variety of cell types effectively. This limitation is primarily due to conventional fabrication methods, such as soft lithography and replica molding. In this research, we introduce a novel coaxial bioprinting method to construct 3D tubular structures that closely emulate the organization and functionality of the small intestine with multiple cell types. To ensure stable production of these small intestine-like tubular structures, we analyzed the rheological properties of bioinks to select the most suitable materials for coaxial bioprinting technology. Additionally, we conducted biological assessments to validate the gene expression patterns and functional attributes of the 3D intestine-on-a-chip. Our 3D intestine-on-a-chip, which faithfully replicates intestinal functions and organization, demonstrates clear superiority in both structure and biological function compared to the conventional 2D model. This innovative approach holds significant promise for a wide range of future applications. [ABSTRACT FROM AUTHOR]

Thread-based microfluidics, which rely on capillary forces in threads for liquid flow, are a promising alternative to conventional microfluidics, as they can be easily integrated into wearable textile-based biosensors. We present here advanced textile-based microfluidic devices fabricated by machine stitching, using only commercially available textiles. We stitch a polyester "Coolmax®" yarn with enhanced wicking abilities into both hydrophobic fabric and hydrophobically treated stretchable fabric, that serve as non-wicking substrates. In doing so we construct textile microfluidics capable of performing a wide variety of functions, including mixing and separation in 2D and 3D configurations. Furthermore, we integrate a stitched microfluidic device into a wearable T-shirt and show that this device can collect, transport, and detect sweat from the wearer's skin. These can also be machine-washed, making them inherently reusable. Finally, we integrate electrochemical sensors into the textile-based microfluidic devices using stitched gold-coated yarns to detect analytes in the microfluidic yarns. Our stitched textile-based microfluidic devices hold promise for wearable diagnostic applications. This novel, bottom-up fabrication using machine stitching is scalable, reproducible, low-cost, and compatible with the existing textile manufacturing industry. [ABSTRACT FROM AUTHOR]

Antibiotic resistance genes (ARGs) pose serious threats to environmental and public health, and monitoring ARGs in wastewater is a growing need because wastewater is an important source. Microfluidic devices can integrate basic functional units involved in sample assays on a small chip, through the precise control and manipulation of micro/nanofluids in micro/nanoscale spaces, demonstrating the great potential of ARGs detection in wastewater. Here, we (1) summarize the state of the art in microfluidics for recognizing ARGs, (2) determine the strengths and weaknesses of portable microfluidic chips, and (3) assess the potential of portable microfluidic chips to detect ARGs in wastewater. Isothermal nucleic acid amplification and CRISPR/Cas are two commonly used identification elements for the microfluidic detection of ARGs. The former has better sensitivity due to amplification, but false positives due to inappropriate primer design and contamination; the latter has better specificity. The combination of the two can achieve complementarity to a certain extent. Compared with traditional microfluidic chips, low-cost and biocompatible paper-based microfluidics is a very attractive test for ARGs, whose fluid flow in paper does not require external force, but it is weaker in terms of repeatability and high-throughput detection. Due to that only a handful of portable microfluidics detect ARGs in wastewater, fabricating high-throughput microfluidic chips, developing and optimizing recognition techniques for the highly selective and sensitive identification and quantification of a wide range of ARGs in complex wastewater matrices are needed. [ABSTRACT FROM AUTHOR]

Developmental toxicity (DevTox) tests evaluate the adverse effects of chemical exposures on an organism's development. Although current testing primarily relies on large mammalian models, the emergence of new approach methodologies (NAMs) is encouraging industries and regulatory agencies to evaluate novel assays. C. elegans have emerged as NAMs for rapid toxicity testing because of its biological relevance and suitability to high throughput studies. However, current low-resolution and labor-intensive methodologies prohibit its application for sub-lethal DevTox studies at high throughputs. With the recent advent of the large-scale microfluidic device, vivoChip, we can now rapidly collect 3D high-resolution images of ~ 1000 C. elegans from 24 different populations. While data collection is rapid, analyzing thousands of images remains time-consuming. To address this challenge, we developed a machine-learning (ML)-based image analysis platform using a 2.5D U-Net architecture (vivoBodySeg) that accurately segments C. elegans in images obtained from vivoChip devices, achieving a Dice score of 97.80%. vivoBodySeg processes 36 GB data per device, phenotyping multiple body parameters within 35 min on a desktop PC. This analysis is ~ 140 × faster than the manual analysis. This ML approach delivers highly reproducible DevTox parameters (4–8% CV) to assess the toxicity of chemicals with high statistical power. [ABSTRACT FROM AUTHOR]

We engineered a microfluidic platform to study the effects of bioactive glass nanoparticles (BGNs) on cell viability under static culture. We incorporated different concentrations of BGNs (1%, 2%, and 3% w/v) in collagen hydrogel (with a concentration of 3.0 mg/mL). The microfluidic chip's dimensions were optimized through fluid flow and mass transfer simulations. Collagen type I extracted from rat tail tendons was used as the main material, and BGNs synthesized by the sol–gel method were used to enhance the mechanical properties of the hydrogel. The extracted collagen was characterized using FTIR and SDS-PAGE, and BGNs were analyzed using XRD, FTIR, DLS, and FE-SEM/EDX. The structure of the collagen-BGNs hydrogels was examined using SEM, and their mechanical properties were determined using rheological analysis. The cytotoxicity of BGNs was assessed using the MTT assay, and the viability of fibroblast (L929) cells encapsulated in the collagen-BGNs hydrogel inside the microfluidic device was assessed using a live/dead assay. Based on all these test results, the L929 cells showed high cell viability in vitro and promising microenvironment mimicry in a microfluidic device. Collagen3-BGNs3 (Collagen 3 mg/mL + BGNs 3% (w/v)) was chosen as the most suitable sample for further research on a microfluidic platform. [ABSTRACT FROM AUTHOR]

We have exploited the unique physics available in microfluidic devices to engineer a platform capable of integrating all critical elements of cell therapy into a microfluidic device. The platform can be used to isolate, count, identify and culture cells on a device in a closed Current Good Manufacturing Practice-compatible system. We have used the culture and isolation of human mature dendritic cells (DCs) as our model system, demonstrating each critical element in manufacturing a therapeutic product. We used the system to immunomagnetically isolate CD14+ cells from peripheral blood mononuclear cells, perform on-chip enumeration and surface marker characterization to confirm purity of isolation (mean, 98.6 ± 1.6%) and culture cells in the presence of cytokines to drive differentiation to CD83+ mature DCs. Successful DC maturation was confirmed using on-chip surface marker characterization (positive CD83 expression) with process yields comparable to conventional DC production. The technology presented is the first demonstration of a chip bioreactor capable of recapitulation of all critical elements of cell therapy manufacturing. Its closed nature, scalability and integration of both manufacturing and release testing show the potential for a new approach to industrialization and rapid distribution of cell therapies. [Display omitted] [ABSTRACT FROM AUTHOR]

Complications from thrombosis constitute a massive global burden for human health. Current treatment methods have limitations and can cause serious adverse effects. Hydrodynamic cavitation (HC) is a physical phenomenon where bubbles develop and collapse rapidly within a moving liquid due to sudden pressure changes. These collapsing bubbles provide high targeted energy which can be used in a controlled environment with the help of microfluidic devices. This study introduces a new clot‐on‐a‐chip (CoC) platform based on HC, evaluated for thrombolysis efficacy. The microfluidic device, paired with a polydimethylsiloxane (PDMS) microchip, generates cavitation bubbles at low upstream pressures (≤482 kPa), enabling microscale blood clot erosion. Different HC exposure conditions (varying pressure and duration) are assessed by changes in clot mass, diameter, and scanning electron microscopy (SEM). The largest mass reduction occurs at 482 kPa for 120 s, with a decrease of 6.1 ± 0.12 mg, while the most erosion in diameter of blood clots is obtained 482 kPa for 120 s with complete removal. SEM results show increasing damage to clot structure from less to more intense HC exposures. The CoC platform, at controlled pressures and durations, efficiently disrupts clot structure and offers a promising drug‐free alternative for thrombolysis treatment. [ABSTRACT FROM AUTHOR]

This article presents a novel plasmonic sensing platform designed for the detection of low molecular weight molecules, offering significant advancements in diagnostic applications. The platform features a periodic array of gold nanodisks on a 20 nm thin silica layer, supported by a 100 nm thick gold substrate. By leveraging the coupling between localized and propagating surface plasmon resonances, this design significantly enhances the sensitivity and specificity of molecular detection. Finite element method simulations are conducted to characterize the optical properties and reflectance response of the nanodisks array in the visible to near‐infrared range. Ellipsometric analysis is performed to measure the reflectance of the sample at various angles. Additionally, scanning near‐field optical microscopy in reflectance mode validates the design by revealing well‐defined plasmonic hot spots and interference patterns consistent with the simulated results. The findings demonstrate the platform's effectiveness in amplifying optical signals, achieving a limit of detection of 50 μM for molecules with a molecular weight of less than 1 KDa. This high sensitivity and specificity highlight the potential of the proposed plasmonic platform to advance the development of highly sensitive sensors for low molecular weight molecules, making it a valuable tool for diagnostics and precise molecular detection. [ABSTRACT FROM AUTHOR]

Microfluidic-based cell-stretching devices are vital for studying the molecular pathways involved in cellular responses to mechanobiological processes. Accurate evaluation of these responses requires detailed observation of cells cultured in this cell-stretching device. This study aimed to develop a method for preparing microscope slides to enable high-magnification imaging of cells in these devices. The key innovation is creating a peelable bond between the cell culture membrane and the upper channel, allowing for easy removal of the upper layer and precise cutting of the membrane for high-magnification microscopy. Using the fabricated device, OP9 cells (15,000 cells/channel) were stretched, and the effects of focal adhesion proteins and the intracellular distribution of YAP1 were examined under a fluorescence microscope with 100× and 60× objectives. Stretch stimulation increased integrinβ1 expression and promoted integrin–vinculin complex formation by approximately 1.4-fold in OP9 cells. Furthermore, YAP1 nuclear localization was significantly enhanced (approximately 1.3-fold) during stretching. This method offers a valuable tool for researchers using microfluidic-based cell-stretching devices. The advancement of imaging techniques in microdevice research is expected to further drive progress in mechanobiology research. [ABSTRACT FROM AUTHOR]

This study evaluates the performance of continuous flow and drop-based microfluidic devices for the synthesis of silver nanoparticles (AgNPs) under identical hydrodynamic and chemical conditions. Flows at low values of Dean number (De < 1) were investigated, where the contribution of the vortices forming inside the drop to the additional mixing inside the reactor should be most noticeable. In the drop-based microfluidic device, discrete aqueous drops serving as reactors were generated by flow focusing using silicone oil as the continuous phase. Aqueous solutions of reagents were supplied through two different channels merging just before the drops were formed. In the continuous flow device, the reagents merged at a Tee junction, and the reaction was carried out in the outlet tube. Although continuous flow systems may face challenges such as particle concentration reduction due to deposition on the channel wall or fouling, they are often more practical for research due to their operational simplicity, primarily through the elimination of the need to separate the aqueous nanoparticle dispersion from the oil phase. The results demonstrate that both microfluidic approaches produced AgNPs of similar sizes when the hydrodynamic conditions defined by the values of De and the residence time within the reactor were similar. [ABSTRACT FROM AUTHOR]

Chronic Kidney Disease (CKD) is a disorder that affects over 10% of the global population, and that would benefit from innovative methodologies that would provide early detection. Since it has been reported that there are high levels of urease in CKD patients' saliva, this sample is a promising non-invasive alternative to blood for CKD detection and monitoring. This work introduces a novel 3D µPAD for quantifying urease activity in saliva in a range of 0.041–0.750 U/mL, with limits of detection and quantification of 0.012 and 0.041 U/mL, respectively. The device uses the urease in the sample to convert urea into ammonia, causing a colorimetric change in the bromothymol blue. The accuracy of the developed device was evaluated by comparing the measurements of several saliva samples (#13) obtained with the μPAD and with a commercially available kit. Stability studies were also performed to assess its functionality as a point-of-care methodology, and the device was stable for 4 months when stored in a vacuum. After the sample placement, it could be scanned within 40 min without providing significantly different results. The developed device quantifies urease activity in saliva within 30 min, providing a simple, portable, lab-free alternative to existing methodologies. [ABSTRACT FROM AUTHOR]

Point-of-care (POC) use is one of the essential goals of biosensing platforms. Because the increasing demand for testing cannot be met by a centralized laboratory-based strategy, rapid and frequent testing at the right time and place will be key to increasing health and safety. To date, however, there are still difficulties in developing a simple and affordable, as well as sensitive and effective, platform that enables POC use. In terms of materials, hydrogels, a unique family of water-absorbing biocompatible polymers, have emerged as promising components for the development of biosensors. Combinations of hydrogels have various additional applications, such as in hydrophilic coatings, nanoscale filtration, stimuli-responsive materials, signal enhancement, and biodegradation. In this review, we highlight the recent efforts to develop hydrogel-assisted biosensing platforms for POC use, especially focusing on polysaccharide hydrogels like agarose, alginate, chitosan, and so on. We first discuss the pros and cons of polysaccharide hydrogels in practical applications and then introduce case studies that test different formats, such as paper-based analytical devices (PADs), microfluidic devices, and independent platforms. We believe the analysis in the present review provides essential information for the development of biosensing platforms for POC use in resource-limited settings. [ABSTRACT FROM AUTHOR]

The Zebrafish International Resource Center (ZIRC) is an NIH-funded national stock center and germplasm repository that maintains and distributes genetically modified and wild-type zebrafish (Danio rerio) lines to the biomedical research community. The ZIRC and its community would benefit from incorporating somatic cell nuclear transfer (SCNT) cloning which would allow the preservation of diploid genomes. The goal of this study was to advance a zebrafish SCNT cloning protocol into a reproducible community-level pathway by use of process mapping and simulation modeling approaches to address training requirements, process constraints, and quality management gaps. Training, for most steps in the SCNT protocol, could be completed within two months; however, steps that involved micromanipulation of eggs required more than four months of training. Dechorionation of embryos and egg micromanipulation were identified as major constraints because the processes were performed manually and required advanced operator manual skills. Chemical dechorionation and microfluidic devices to aid micromanipulation were identified as ways to eliminate these constraints. Finally, quality control steps to record the initial quality of collected germplasm were recommended to prevent production defects and harmonize the SCNT pathway across multiple facilities. By beginning to enhance the reproducibility of the SCNT cloning pathway, this technique can be implemented across zebrafish research facilities and facilities that work with other biomedical models. [ABSTRACT FROM AUTHOR]

In this study, polymethyl methacrylate (PMMA) is joined with fused silica using pulsed femtosecond laser transmission micro‐welding. This technique enables the welding of transparent materials to each other without the need for intermediate opaque layers, through localized energy deposition. The laser parameters – peak fluence, scanning speed, and hatch distance – are systematically optimized to maximize joint shear strength. The ATR‐FTIR spectroscopic analysis has proven that mechanical interlocking is the primary mechanism of joint formation between the two materials. An analytical model based on heat accumulation is developed to describe the joining process, with a good predictive quality confirmed by comparison with the experimental results. This joining approach is applied to seal a hybrid PMMA‐fused silica microfluidic chip. The device has successfully passed a static leakage test by withstanding pressures up to the full‐scale value of the employed microfluidic pump at 2 bar, demonstrating the effectiveness of femtosecond laser transmission welding for fabricating robust and reliable joints in hybrid microfluidic devices. [ABSTRACT FROM AUTHOR]

Microelectrodes play a crucial role in microfluidic chips. However, electrodes with micron‐sized geometries lead to undesired impedance increases and processing difficulties. This study introduces a method for preparing low‐resistance and low‐cost liquid metal microelectrodes (μLMEs$\umu{\rm LMEs}$), which leverages the distinct phase transition properties of liquid metal (LM) gallium (Ga) and Poly‐N‐Isopropylacrylamide (PNIPAM), along with the reversible bonding between PNIPAM and polydimethylsiloxane (PDMS). PNIPAM is spin‐coated as a sacrificial layer on silanized glass and heated to dehydration. As it hydrates and swells in the water bath, Ga/PDMS can be easily peeled off, forming a precision surface‐embedded μLME$\umu{\rm LME}$. The resistance of the μLME$\umu{\rm LME}$ with a thickness of 25 μm$\umu{\rm m}$ was only 9.3% and 0.077% of the 100nm thin film Au and indium tin oxide (ITO) film microelectrode with the same plane size. Hydration and swelling of the sacrificial layer ensured the fabrication with high resolutions down to 5 μm$\umu{\rm m}$ and an acute angle of 15°. The electroosmotic flow tests show that the μLME$\umu{\rm LME}$ effectively reduces the operating voltage compared to conventional planar Au or ITO microelectrodes. These features make it a promising candidate for electrification requirements in microfluidic devices. [ABSTRACT FROM AUTHOR]

The "Lab on a Chip" journal published by The Royal Society of Chemistry features various papers on micro- and nanoscale devices and applications. The latest issue includes research on topics such as antimicrobial susceptibility testing, stem cell culture monitoring, health monitoring using sweat sensing, and energy harvesting methods. Additionally, studies on retinal pathologies, virus pathogenesis, root growth responses, flow dynamics in microfluidics, and protein complex purification are also highlighted in this issue. [Extracted from the article]

Co-flow microfluidics, in addition to its applications in droplet generation, has gained popularity for use with miscible solvent systems (continuous microfluidics). By leveraging the short diffusional distances in miniature devices, processes like nanomaterial synthesis can be precisely tailored for high-throughput production. In this context, the manipulation of flow regimes—from laminar to vortex formation, as well as the generation of turbulent and turbulent jet flows—plays a significant role in optimizing these processes. Therefore, a detailed understanding of fluid interactions within microchannels is crucial. Imaging with tracer particles is a commonly used approach to study fluid behavior. Alternatively, label-free imaging methodologies are rarely employed for studying fluid dynamics. In this pursuit, we present a new imaging-based scheme to explore fluid interactions in various co-flow regimes through optical flow analysis, specifically using Gaussian window mean squared error (MSE). By examining fluid flow characteristics such as flow intensities (caused by fluctuations) and the projected movement of fluid spots, we characterize slow vortexing and chaotic flow behaviors in co-flow regimes. Consequently, we use imaging data to illustrate the influence of co-flow regimes on particle synthesis. This new tool provides the scientific community with an innovative method to study fluid interactions, which can be further explored to develop a more effective understanding of fluid mixing and optimize fluid manipulation in microfluidic devices. [ABSTRACT FROM AUTHOR]

This paper focuses on the study of Blasius–Rayleigh–Stokes nanofluid dusty flow with generalized Fourier and Fick laws under the influence of a transitive magnetic field. The Blasius–Rayleigh–Stokes nanofluid dusty flow has significant applications in various fields, including the design of heat exchangers, microfluidic devices and industrial processes involving the transportation of suspended particles in fluids. This paper considers the impact of melting heat transfer at the surface boundary. By employing relevant transformations, the mathematical model is transformed into a system of self-similar equations. The solution to this set of highly nonlinear equations is obtained using the bvp4c numerical method in combination with the response surface methodology (RSM) statistical approach. The results are presented through graphical illustrations and numerically calculated tabulated values. It is observed that the fitted model for the skin friction coefficient Re x 1 ∕ 2 C f optimal. Moreover, the model parameters Pr , Q, β v , M and L are linearly and quadratically significant in explaining the variation presented for skin friction coefficient Re x 1 ∕ 2 C f . This indicates the response skin friction coefficient Re x 1 ∕ 2 C f is minimized to 0.005 at Pr = 2. 2 0 2 7 , Q = 0. 2 5 2 , β v = 0. 2 2 , M = 0. 2 1 7 and L = 0. 2 5 2 and is maximized to 1.387 at Pr = 2. 0 6 6 , Q = 0. 2 5 4 , β v = 0. 0 2 1 , M = 0. 0 5 6 and L = 0. 2 5 2. [ABSTRACT FROM AUTHOR]

Acoustofluidics is a promising technology that leverages acoustic waves for precise manipulation of micro/nano‐scale flows and suspended objects within microchannels. Despite many advantages, the practical applicability of conventional acoustofluidic platforms is limited by irreversible bonding between the piezoelectric actuator and the microfluidic chip. Recently, reconfigurable acoustofluidic platforms are enabled by reversible bonding between the reusable actuator and the replaceable polydimethylsiloxane (PDMS) microfluidic chip by incorporating a PDMS membrane for sealing the microchannel and coupling the acoustic waves with the fluid inside. However, a quantitative guideline for selecting a suitable PDMS membrane for various acoustofluidic applications is still missing. Here, a design rule for reconfigurable acoustofluidic platforms is explored based on a thorough investigation of the PDMS thickness effect on acoustofluidic phenomena: acousto–thermal heating (ATH), acoustic radiation force (ARF), and acoustic streaming flow (ASF). These findings suggest that the relative thickness of the PDMS membrane (t) for acoustic wavelength (λPDMS) determines the wave attenuation in the PDMS and the acoustofluidic phenomena. For t/λPDMS ≈ O(1), the transmission of acoustic waves through the membrane leads to the ARF and ASF phenomena, whereas, for t/λPDMS ≈ O(10), the acoustic waves are entirely absorbed within the membrane, resulting in the ATH phenomenon. [ABSTRACT FROM AUTHOR]

On‐site rapid multi‐ion sensing accelerates early identification of environmental pollution, water quality, and disease biomarkers in both livestock and humans. This study introduces a pocket‐sized 3D‐printed sensor, manufactured using additive manufacturing, specifically designed for detecting iron (Fe2+), nitrate (NO3–), calcium (Ca2+), and phosphate (HPO42−). A unique feature of this device is its utilization of a universal ion‐to‐electron transducing layer made from highly redox‐active poly‐octylthiophene (POT), enabling an all‐solid‐state electrode tailored to each ion of interest. Manufactured with an extrusion‐based 3D printer, the device features a periodic pattern of lateral layers (width = 80 µm), including surface wrinkles. The superhydrophobic nature of the POT prevents the accumulation of nonspecific ions at the interface between the gold and POT layers, ensuring exceptional sensor selectivity. Lithography‐free, 3D‐printed sensors achieve sensitivity down to 1 ppm of target ions in under a minute due to their 3D‐wrinkled surface geometry. Integrated seamlessly with a microfluidic system for sample temperature stabilization, the printed sensor resides within a robust, pocket‐sized 3D‐printed device. This innovation integrates with milking parlors for real‐time calcium detection, addressing diagnostic challenges in on‐site livestock health monitoring, and has the capability to monitor water quality, soil nutrients, and human diseases. [ABSTRACT FROM AUTHOR]

Reciprocal structure–function relationships underlie both healthy and pathological behaviours in complex neural networks. Thus, understanding neuropathology and network dysfunction requires a thorough investigation of the complex interactions between structural and functional network reconfigurations in response to perturbation. Such adaptations are often difficult to study in vivo. For example, subtle, evolving changes in synaptic connectivity, transmission and the electrophysiological shift from healthy to pathological states, for example alterations that may be associated with evolving neurodegenerative disease, such as Alzheimer's, are difficult to study in the brain. Engineered in vitro neural networks are powerful models that enable selective targeting, manipulation and monitoring of dynamic neural network behaviour at the micro‐ and mesoscale in physiological and pathological conditions. In this study, we engineered feedforward cortical neural networks using two‐nodal microfluidic devices with controllable connectivity interfaced with microelectrode arrays (mMEAs). We induced P301L mutated tau protein to the presynaptic node of these networks and monitored network dynamics over three weeks. Induced perturbation resulted in altered structural organization and extensive axonal retraction starting in the perturbed node. Perturbed networks also exhibited functional changes in intranodal activity, which manifested as an overall decline in both firing rate and bursting activity, with a progressive increase in synchrony over time and a decrease in internodal signal propagation between pre‐ and post‐synaptic nodes. These results provide insights into dynamic structural and functional reconfigurations at the micro‐ and mesoscale as a result of evolving pathology and illustrate the utility of engineered networks as models of network function and dysfunction. [ABSTRACT FROM AUTHOR]

Extracellular vesicles (EVs) are promising biomarkers for diagnosing complex diseases such as cancer and neurodegenerative disorders. Yet, their clinical application is hindered by challenges in isolating cancer-derived EVs efficiently due to their broad size distribution in biological samples. This study introduces a microfluidic device fabricated using off-stoichiometry thiol-ene and cyclic olefin copolymer, addressing the absorption limitations of polydimethylsiloxane (PDMS). The device streamlines a standard laboratory assay into a semi-automated microfluidic chip, integrating sample mixing and magnetic particle separation. Using the microfluidic device, the binding kinetics between EVs and anti-CD9 nanobodies were measured for the first time. Based on the binding kinetics, already after 10 min the EV capture was saturated and comparable to standard laboratory assays, offering a faster alternative to antibody-based immunomagnetic protocols. Furthermore, this study reveals the binding kinetics of EVs to anti-CD9 nanobodies for the first time. Our findings demonstrate the potential of the microfluidic device to enhance clinical diagnostics by offering speed and reducing manual labor without compromising accuracy. [ABSTRACT FROM AUTHOR]

Microfluidic BBB‐on‐a‐chip models (μBBB) aim to recapitulate the organotypic features of the human BBB with great potential to model CNS diseases and advance CNS therapeutics. Nevertheless, their predictive capacity for drug uptake into the brain remains uncertain due to limited evaluation with only a small number of model drugs. Here, the in vivo brain uptake of a panel of nine radiolabeled compounds is evaluated in Swiss‐outbred mice following a single intravenously administered dose and compared against results from the microfluidic μBBB platform and the conventional Transwell BBB model. Radioisotopic measurements are employed to calculate brain‐to‐plasma concentration ratios (B/P) of the compounds both in vivo and in vitro. The in vitro‐in vivo correlation plots of the B/P ratios revealed a strong positive correlation (r = 0.8081, R2 = 0.6530) for the μBBB, suggesting a high degree of predictive ability for drug permeability into the brain. In contrast, the Transwell assay showed a weaker in vitro‐in vivo correlation (r = 0.6467, R2 = 0.4182). Finally, brain uptake of radiolabeled, brain‐targeted, angiopep2‐conjugated nanoparticles (ANG2‐NP) is assessed in the μBBB and results mirrored the in vivo uptake, while the Transwell model failed to resolve the differences between the targeted and non‐targeted NPs. [ABSTRACT FROM AUTHOR]

Hydrogel‐based microchannels with biologically similar morphologies and properties can provide excellent platforms for advanced tissue/organ formation in vitro. However, there are still many restrictions on channel morphology, material selection, tubing connections, etc. Here, a novel and versatile method is proposed that couples cononsolvency photopolymerization, which enables the incorporation of porous structures into hydrogels, with on‐chip microchannels formed by buckling of a thin film. This method provides a hydrogel‐based microchannel with improved permeability while maintaining its mechanical properties by incorporating a continuous porous structure into a synthetic polymer network with excellent mechanical properties. Furthermore, by culturing vascular endothelial cells into the microchannel, it is demonstrated that the microchannel works as a vessel‐on‐a‐chip platform that can be used for the evaluation of barrier function, fabrication of various channel shapes, and development of co‐culture systems. This method, which can be adapted to various swellable hydrogels, can provide platforms with properties and functions tailored to the tissue/organ and, thus, it will contribute to the creation of physiologically relevant biological models. [ABSTRACT FROM AUTHOR]

Cell-based assays are widely exploited for drug screening and biosensing, providing useful information about bioactivity of target analytes and complex biological samples. It is well recognized that 3D cell models are required to achieve highly valuable information, also from the perspective of replacing animal models. However, bioassays relying on 3D cell models are generally highly demanding in terms of facilities, equipment, and skilled personnel requirements. To reduce cost, increase sustainability, and provide a flexible 3D cell-based platform for bioassays, we here report a novel approach based on a 3D-printed microtissue device. To assess the suitability of this strategy for reporter gene technology, we selected to monitor two molecular pathways which were of interest in several applications, hypoxia signaling and the p53 pathway. The investigation of such pathways is highly relevant in fields spanning from drug screening to bioactivity monitoring for industrial by-product valorization. Microtissues of human hepatocarcinoma (HepG2) and human embryonic kidney (Hek293T) cell lines were obtained with a low-cost and sustainable chip platform and bioassays were developed to monitor the hypoxia-inducible factors (HIFs) and the p53 tumor suppressor pathway. HepG2 and Hek293T 3D cell models were genetically engineered to express the Luc2P from Photinus pyralis firefly either under the regulation of p53 or HIF response elements. The bioassays allowed quantitative assessment of hypoxia and tumoral activity with 1,10-phenanthroline for HIF and with doxorubicin for p53 pathway activation, respectively, showing good potential for applications of this sustainable and low-cost 3D-printed microfluidic platform for bioactivity analyses, drug screening, and precision medicine. [ABSTRACT FROM AUTHOR]

The article "Sorting capsules in microfluidic devices" published in the Journal of Fluid Mechanics discusses the use of microfluidic systems for sorting and enriching deformable particle suspensions. The study by Lu et al. explores the interactions between suspended capsules and surrounding fluid in a branched microchannel, providing insights for precise control of microfluidic devices. The research has implications for biotechnology applications and offers guidance for experimental setups. The study's findings can be applied to understand flows of deformable cells in complex geometries and have potential applications in microvascular flows and cancer metastasis research. [Extracted from the article]

Brain-on-a-chip is an emerging field involving microfluidic devices capable of mimicking the structure and function of the human brain. Existing research often focuses on single barriers, such as the blood–brain barrier or blood–cerebrospinal fluid barrier (BCSFB). However, the brain has both barriers working together, and mimicking this dual system is crucial for better understanding of brain (patho)physiology. In this work, we present a four-channel microfluidic chip model that incorporates both the BBB and BCSFB, to reproduce physiologically correct architecture. Using computer simulations, we demonstrate that this model can mimic both healthy and diseased states by adjusting the shear stress experienced by the barriers, which is a key factor in their function. These findings offer valuable insights for designing future brain-on-a-chip devices with improved accuracy. This improved technology could contribute to wider advancements in tissue engineering and the study of brain function and diseases. [ABSTRACT FROM AUTHOR]

When exposed to an alternating current (AC) electric field, a polarized microparticle is moved by the interaction between the voltage-induced dipoles and the AC electric field under dielectrophoresis (DEP). The DEP force is widely used for manipulation of microparticles in diverse practical applications such as 3D manipulation, sorting, transfer, and separation of various particles such as living cells. In this study, we propose the integration of surface-enhanced Raman spectroscopy (SERS), an extremely sensitive and versatile technique based on the Raman scattering of molecules supported by nanostructured materials, with DEP using a microfluidic device. The microfluidic device combines microelectrodes with gold nanohole arrays to characterize the electrophysiological and biochemical properties of biological cells. The movement of particles, which varies depending on the electrical properties such as conductivity and permittivity of particles, can be manipulated by the cross-frequency change. For proof of concept, Raman spectroscopy using the DEP–SERS integration was performed for polystyrene beads and biological cells and resulted in an improved signal-to-noise ratio by determining the direction of the DEP force applied to the cells with respect to the applied AC power and collecting them on the nanohole arrays. The result illustrates the potential of the concept for simultaneously examining the electrical and biochemical properties of diverse chemical and biological microparticles in the microfluidic environment. [ABSTRACT FROM AUTHOR]

Engineered living materials (ELMs) harness engineered cells to fabricate functional materials with lifelike characteristics, offering unparalleled potential across various fields. Nonetheless, the deployment of ELM‐based biosensors beyond laboratory settings remains challenging. Herin, ELMs are explored as field‐deployable biosensing laboratories on a microfluidic chip (ELMlab‐on‐Chip) for the simultaneous detection of diverse analytes in the field. This approach engages a bottom‐up strategy that includes the molecular engineering of living biosensors, the construction of stimuli‐responsive ELMs, and the fabrication of an integrated biosensing device. Specifically, living biosensors are engineered with fine‐tuned sensitivity and response by designing chimeric receptors and precisely controlling receptor concentration. Integrating ionic and covalent cross‐linking strategies in manufacturing ELMs ensures good substance permeability and mechanical robustness. Moreover, a microfluidic chip is devised tailored for the orthogonally stimuli‐responsive ELMs, creating a spatially encoded sensor array with the output detected by a miniaturized smartphone‐based detection device. The integrated ELMlab‐on‐Chip platform has demonstrated its potential in the simultaneous analysis of multiple chemicals from a single environmental sample under field conditions, offering an effective strategy to expedite the real‐world application of living materials. [ABSTRACT FROM AUTHOR]

Successful axonal regeneration following injury requires the effective allocation of energy. How axons withstand the initial disruption in mitochondrial energy production caused by the injury and subsequently initiate regrowth is poorly understood. Transcriptomic data showed increased expression of glycolytic genes after optic nerve crush in retinal ganglion cells with the co-deletion of Pten and Socs3. Using retinal cultures in a multicompartment microfluidic device, we observed increased regrowth and enhanced mitochondrial trafficking in the axons of Pten and Socs3 co-deleted neurons. While wild-type axons relied on mitochondrial metabolism, after injury, in the absence of Pten and Socs3, energy production was supported by local glycolysis. Specific inhibition of lactate production hindered injury survival and the initiation of regrowth while slowing down glycolysis upstream impaired regrowth initiation, axonal elongation, and energy production. Together, these observations reveal that glycolytic ATP, combined with sustained mitochondrial transport, is essential for injury-induced axonal regrowth, providing new insights into the metabolic underpinnings of axonal regeneration. [ABSTRACT FROM AUTHOR]

Gynecological cancers, including cervical, endometrial, and ovarian cancer, contribute to a significant portion of female cancer-related deaths. Despite advancements in cancer detection, these diseases continue to pose challenges due to limited cost-effective screening methods and late-stage diagnoses. This review paper focuses on the utilization of microfluidic devices (MFDs) as a cost-effective tool for diagnosing and screening gynecological cancers. MFDs are portable instruments capable of sample separation, extraction, dilution, mixing, and biomarker detection. Their compact size and efficiency make them advantageous for comprehensive sample analysis. The emergence of microfluidic point-of-care devices offers potential for developing biomarker-based screening technologies and facilitating early detection of gynecological cancers. This paper aims to consolidate the knowledge and findings surrounding the utilization of MFDs in gynecological cancer research by summarizing the current literatures that exist between 2006 and 2023. The review of previous research in this area will contribute to a comprehensive understanding of the recent state of utilizing MFDs for gynecological cancer screening and detection as it will shed light on the advancements made thus far and provide insights into the future prospects and potential directions of research in this field. [ABSTRACT FROM AUTHOR]

AbstractA rapid, sensitive, and low-damage method for isolating circulating tumor cells (CTCs) is crucial for cancer research. This study, based on dielectrophoresis (DEP) and finite element modeling, investigates multitarget cell separation from blood on microfluidic chips. The effects of electrode shape, dielectric conductivity, and flow rate on cell movement and separation efficiency were analyzed. The results showed optimal separation with a 90° electrode angle, 1.5 V applied voltage, and a 1:3 inlet flow rate ratio. This study provides valuable insights for optimizing DEP-based microfluidic devices to improve multitarget cell separation efficiency and purity. [ABSTRACT FROM AUTHOR]