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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]

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]

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]

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]

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]

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]

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]

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]

Femtosecond laser processing has become a critical technique for the microfabrication of hard and brittle materials, particularly in microfluidic device applications. This study focuses on the fabrication of microchannels with controllable cross-sectional profiles in silica glass, a material known for its excellent physical and chemical properties. Through a combination of experimental research and theoretical analysis, the surface generation mechanisms governing microchannel morphology are investigated, alongside the influence of various processing parameters on the surface roughness at the microchannel bottom. A comprehensive optimization method is developed to control sidewall taper and surface roughness by adjusting laser scanning paths and modes. Utilizing a composite scanning approach, the study achieves near-rectangular microchannels with average sidewall taper angles below 5° and surface roughness (Sa) of 2.53 μm. These results provide a new strategy for precise control of microchannel morphology in silica glass, offering significant potential to enhance the efficiency and precision of microfluidic device fabrication, with broad applications in both industrial and research settings. [ABSTRACT FROM AUTHOR]

Background: Organ-on-a-chip models have emerged as transformative tools in ophthalmology, offering physiologically relevant platforms for studying ocular diseases and testing therapeutic interventions. These microfluidic devices replicate human eye tissue architecture, addressing limitations of traditional in vitro and animal models. Methods: A narrative review of recent advancements in organ-on-a-chip technology was conducted, focusing on models simulating ocular structures like the retina and cornea and their applications in studying diseases such as dry eye disease (DED), age-related macular degeneration (AMD), and glaucoma. Results: Advanced organ-on-a-chip models successfully mimic key ocular features, providing insights into disease mechanisms and therapeutic responses. Innovations in microengineering and cellular integration have enhanced these platforms' translational potential, though challenges like scalability and regulatory validation persist. Conclusions: Organ-on-a-chip models are poised to enhance preclinical research and clinical applications in ophthalmology. Addressing scalability and regulatory hurdles will be key to unlocking their full potential in drug discovery and disease modeling. [ABSTRACT FROM AUTHOR]

Platelet transfusion is a lifesaving therapy intended to prevent and treat bleeding. However, in addition to platelets, a typical unit also contains a large volume of supernatant that accumulates multiple pro-inflammatory contaminants, including residual leukocytes, microaggregates, microparticles, antibodies, and cytokines. Infusion of this supernatant is responsible for virtually all adverse reactions to platelet transfusions. Conventional methods for removing residual leukocytes (leukoreduction) and reducing the volume of transfused supernatant (volume reduction) struggle to mitigate these risks holistically. Leukoreduction filters can remove leukocytes and microaggregates but fail to reduce supernatant volume, whereas centrifugation can reduce volume, but it is ineffective against larger contaminants and damages platelets. Additionally, platelet purification based on these methods is often too logistically complex, time-consuming, and labor-intensive to implement routinely. Emerging microfluidic technologies offer promising alternatives through passive separation mechanisms that enable cell separation with minimal damage and drastically reduced instrumentation size and facility requirements. This review examines recent innovations in microfluidic cell separation that can be used for leukoreduction and volume reduction of platelets. It begins by defining the performance requirements that any separation method must meet to successfully replace conventional methods currently used to perform these tasks. Standard performance metrics are described, including leukocyte depletion efficiency, degree of volume reduction, processing throughput, and platelet recovery. Finally, the review outlines the primary challenges that must be overcome to enable simple-to-use, disposable microfluidic devices capable of both reducing the platelet unit volume and removing pro-inflammatory contaminants, while preserving most functional platelets for transfusion. [ABSTRACT FROM AUTHOR]

Microfluidic devices have many unique practical applications across a wide range of fields, making it important to develop accurate models of these devices, and many different models have been developed. Existing modeling methods mainly include mechanism derivation and semi-empirical correlations, but both are not universally applicable. In order to achieve a more accurate and general modeling process, the use of data-driven modeling has been studied recently. This review highlights recent advances in the application of data-driven modeling techniques for simulating and designing microfluidic devices. First, it introduces the application of traditional modeling approaches in microfluidics; subsequently, through different database sources, it reviews studies on data-driven modeling in three categories; and finally, it raises some open issues that require further investigation. [ABSTRACT FROM AUTHOR]

This review describes mechanisms for pulling fluids through microfluidic devices using hydrophilic structures at the downstream end of the device. These pumps enable microfluidic devices to get out of the lab and become point-of-care devices that can be used without external pumps. We briefly summarize prior related reviews on capillary, pumpless, and passively driven microfluidics then provide insights into the fundamental physics of wicking pumps. No prior reviews have focused on wicking pumps for microfluidics. Recent progress is divided into four categories: porous material pumps, hydrogel pumps, and 2.5D- and 3D-microfabricated pumps. We conclude with a discussion of challenges and opportunities in the field, which include achieving constant flow rate, priming issues, and integration of pumps with devices. [ABSTRACT FROM AUTHOR]

Bio-microfluidic technologies offer promising applications in diagnostics and therapy, yet they face significant technical challenges, particularly in the need for external power sources, which limits their practicality and user-friendliness. Recent advancements have explored innovative methods utilizing body fluids, motion, and heat to power these devices, addressing the power supply issue effectively. Among these, body-motion and body-heat-powered systems stand out for their potential to create self-sustaining, wearable, and implantable devices. In this Perspective, we focus on the principles and applications of hydrovoltaic cells, biofuel cells, and piezoelectric and triboelectric nanogenerators. Recent strides in energy conversion efficiency, coupled with the development of biocompatible and durable materials, are driving innovation in bio-integrated electronics. Integration with bio-microfluidic platforms further enhances the linkage to the human body and the potential of these devices for personalized healthcare applications. Ongoing research into these areas promises to deliver sustainable and user-friendly solutions for continuous monitoring, diagnostics, and therapy, potentially revolutionizing the landscape of healthcare delivery. [ABSTRACT FROM AUTHOR]

Drug delivery technologies, which are a crucial area of research in the field of cell biology, aim to actively or passively deliver drugs to target cells to enhance therapeutic efficacy and minimize off-target effects. In recent years, with advances in drug development, particularly, the increasing demand for macromolecular drugs (e.g., proteins and nucleic acids), novel drug delivery technologies and intracellular cargo delivery systems have emerged as promising tools for cell and gene therapy. These systems include various viral- and chemical-mediated methods as well as physical delivery strategies. Physical methods, such as electroporation and microinjection, have shown promise in early studies but have not been widely adopted due to concerns regarding efficiency and cellular viability. Recently, microfluidic technologies have provided new opportunities for cargo delivery by allowing for precise control of fluid dynamic parameters to achieve efficient and safe penetration of cell membranes, as well as for foreign material transport. Microfluidics-based mechanical delivery methods utilize biophysical phenomena, such as cell constriction and fluid shear, and are associated with high throughput and high transfection efficiency. In this review, we summarize the latest advancements in microfluidic mechanical delivery technologies, and we discuss constriction- and fluid shear-induced delivery strategies. Furthermore, we explore the potential application of artificial intelligence in optimizing cargo delivery technologies, aiming to provide theoretical support and practical guidance for the future development of novel cellular drug delivery technologies. [ABSTRACT FROM AUTHOR]

The incidence of stroke is on the rise globally. This affects one in every four individuals each year, underscoring the urgent need for early warning and prevention systems. The existing research highlights the significance of monitoring blood viscosity in stroke risk evaluations. However, the current methods lack the precision to measure viscosity under low shear rate conditions (<100 s⁻¹), which are observed during pulsatility flow. This study addresses this gap by introducing a novel microfluidic platform designed to measure blood viscosity with high precision under pulsatility flow conditions. The systolic blood viscosity (SBV) and diastolic blood viscosity (DBV) can be differentiated and evaluated by using this system. The non-Newtonian behavior of blood is captured across specific shear rate conditions. The platform employs a meticulously designed microarray to simulate the variations in blood viscosity during pulsation within blood vessels.The results demonstrate an impressive accuracy of 95% and excellent reproducibility when compared to traditional viscometers and rheometers and are within the human blood viscosity range of 1–10 cP. This monitoring system holds promise as a valuable addition to stroke risk evaluation methods, with the potential to enhance prediction accuracy. [ABSTRACT FROM AUTHOR]

Since the emergence of microfluidic devices, subtractive manufacturing techniques have dominated their production. Although the conventional manufacturing processes are well established, they come along with some disadvantages that limit the accessibility and hinder the further development of microfluidics. With the rise of additive manufacturing, researchers are focused on developing alternative fabrication methods to promote affordability and accessibility. This paper presents the opportunities and challenges of laser-based stereolithography printers for the fabrication of microfluidic equipment. Emphasis is put on the design and iterative prototyping process from the initial design idea to the final device. To print with adequate and sufficient geometrical accuracy and suitable material, the optimization of the printer's performance is discussed. Regarding the design of multiphase microfluidics and its complex fluid behavior, suitable surface treatments, including an appropriate cleaning protocol, and coating strategies to make the printed channels either hydrophilic or hydrophobic are presented to ensure applicability. With these fundamentals of additive manufacturing in microfluidic fabrication at hand, the second focus of this contribution is on the application of a modular co-flow device and a monolithic flow-focusing device to generate droplets and slugs in different multiphase flow applications. The presented co-flow setup features a tapered capillary that affects the droplet and slug sizes due to differing diameters, with larger diameters leading to larger droplets and slugs and vice versa. Several design parameters for the flow-focusing device were evaluated to determine the influence of device design on multiphase flow formation. It was found that the diameter of the inlet for the dispersed phase has the greatest effect on the size of the resulting droplets and slugs and covers the largest range of adjustable sizes. [ABSTRACT FROM AUTHOR]

Microfluidic devices offer promising solutions for automating various biological and chemical procedures. Epoxy resin, known for its excellent mechanical properties, chemical resistance, and thermal stability, is widely used in high-performance microfluidic devices. However, the poor printability of epoxy has limited its application in 3D printing technologies for fabricating epoxy-based microfluidic devices. In this study, fumed silica is introduced into epoxy resin to formulate a yield-stress fluid suspension as a support bath for embedded 3D printing (e-3DP). The study demonstrates that increasing the fumed silica concentration from 3.0% to 9.0% (w/v) enhances the yield stress from 9.46 Pa to 56.41 Pa, the compressive modulus from 19.79 MPa to 36.34 MPa, and the fracture strength from 148.16 MPa to 168.78 MPa, while reducing the thixotropic time from 6.58 s to 1.32 s, albeit with a 61.3% decrease in the transparency ratio. The 6.0% (w/v) fumed silica–epoxy suspension is selected based on a balance between yield stress, transparency, and mechanical performance, enabling high-fidelity filament formation. Two representative microfluidic devices are successfully fabricated, demonstrating the feasibility of a fumed silica–epoxy suspension for the customizable e-3DP of epoxy-based microfluidic devices. [ABSTRACT FROM AUTHOR]

A synthetic jet actuator (SJA) is a fluidic device often consisting of a vibrating diaphragm that alters the volume of a cavity to produce a synthesized jet through an orifice. The cyclic ingestion and expulsion of the working fluid leads to a zero-net mass-flux and the transfer of linear momentum to the working fluid over an actuation cycle, leaving a train of vortex structures propagating away from the orifice. SJAs are a promising technology for flow control applications due to their unique features, such as no external fluid supply or ducting requirements, short response time, low weight, and compactness. Hence, they have been the focus of many research studies over the past few decades. Despite these advantages, implementing an effective control scheme using SJAs is quite challenging due to the large parameter space involving several geometrical and operational variables. This article aims to explain the working mechanism of SJAs and provide a comprehensive review of the effects of SJA design parameters in quiescent conditions and cross-flow. [ABSTRACT FROM AUTHOR]

Including specific interfacial area and saturation of the percolating phase into two‐phase porous media flow models, on the Darcy scale, enhances our ability to capture the physical properties of porous media flow more effectively. Using optical microscopy and microfluidic devices, we perform sequential drainage and imbibition experiments. The relevant processes, images, and boundary pressures are monitored, recorded, and logged at all times. For comparative purposes, two PDMS micromodels are used, one with an ortho‐canonical, homogeneous, and the other with a periodic heterogeneous pore network, with similar macro‐ but different pore‐scale properties. After processing the images, parameters like interfacial area belonging to percolating and non‐percolating phases and the corresponding phase saturations are determined. Our experimental results show that the relation between specific interfacial area and saturation of the percolating invading phase is a linear relationship with interesting properties. Additionally, after a number of fluid displacement processes (drainage and imbibition), and for both pore networks, unique flow paths for both phases are formed. We speculate that this happens due to the establishment of an effective porous medium, meaning a hydro‐dynamically active region within the pore space where the corresponding phase remains connected and flowing, where the capillary forces act as the guide for creating the "path of least resistance" in a highly viscous flow regime by keeping the non‐percolating phases in place. As the results can be specific to our experiments, more work needs to be done toward the potential generalization of these findings, especially in 3D flow domains. Plain Language Summary: A thorough understanding of multiphase flow in porous media is essential to designing engineering processes in which several fluid phases flow in a porous medium. However, multiphase flow models on the continuum scale are still strongly conditional and have limited predictability. In this work, we investigate combining two of these theories to see if that would get us closer to a physics‐consistent approach in modeling two‐phase porous media flow. One of the theories considers the common surface between the two phases (known as interfacial area) in its models. The other theory discriminates between the flowing and stranded fluid elements (known as percolating and non‐percolating fluid clusters). We conduct displacement experiments in artificial porous media (known as micromodels), record the processes using optical microscopy, and analyze the images using image processing. Our results show that a modeling approach where both essential elements of the above‐mentioned theories are considered captures the properties of the displacement process more efficiently. This might hint toward finding more efficient continuum theories for multiphase porous media flow. Another notable outcome is observing the formation of an effective porous medium, where the non‐percolating fluid clusters obstruct parts of the original medium, creating a new flow domain. Key Points: Specific interfacial area versus saturation of percolating clusters exhibits a linear behavior, for all studied flow rates and pore geometriesAfter a certain number of imbibition‐drainage cycles a common effective flow pathway forms for the flowing phaseEven in capillarity‐dominated flows, the conditions can change to viscous since the non‐percolating clusters alter the available pore space [ABSTRACT FROM AUTHOR]

The small dimensions of microfluidic channels allow for fast diffusive or passive mixing, which is beneficial for time-sensitive applications such as chemical reactions, biological assays, and the transport of to-be-detected species to sensors. In microfluidics, the need for fast mixing within milliseconds arises primarily because these devices are often used in fields where rapid and efficient mixing significantly impacts the performance and outcome of the processes. Active mixing with acoustics in microfluidic devices involves using acoustic waves to enhance the mixing of fluids within microchannels. Using sharp corners and wall patterns in acoustofluidic devices significantly enhances the mixing by acoustic streaming around these features. The streaming patterns around the sharp edges are particularly effective for the mixing because they can produce strong lateral flows that rapidly homogenize liquids. This work presents extensive characterizations of the effect of sharp-edged structures on acoustic mixing in bulk acoustic wave (BAW) mode in a silicon microdevice. The effect of side wall patterns in different angles and shapes, their positions, the type of piezoelectric transducer, and its amplitude and frequency have been studied. Following the patterning of the channel walls, a mixing time of 25 times faster was reached, compared to channels with smooth side walls exhibiting conventional BAW behavior. The average locally determined acoustic streaming velocity inside the channel becomes 14 times faster if sharp corners of 10° are added to the wall. [ABSTRACT FROM AUTHOR]

Detecting and quantifying pharmaceutical compounds in various environmental matrices is complex and challenging. This difficulty stems from the trace levels at which these compounds are found and the lack of analytical methods that are rapid, cost-effective, and portable. To address these challenges, this study aimed to develop microfluidic paper-based analytical devices (μ-PADs) using beeswax screen printing for fabrication. Key parameters, including reaction time, concentration, reagent volume, and channel length, were optimized using response surface methodology. Under optimal conditions of 5 ppm sample concentration, 10 μL reagent volume, 10 min reaction time, and 2 cm channel length, the analytical performance of the μPAD was evaluated and compared with the standard UV–Vis spectrophotometry method. The microfluidic analytical device demonstrated detection limits at 0.03 μg/ml, compared to 0.01 μg/ml for the UV–Vis spectrophotometer. Although the sensitivity of µ-PADs in this study (0.03 μg/ml) is lower than that of UV–Vis (0.01 μg/ml), it represents an improvement over the previous µ-PAD report (1 μg/ml) on the same analytes. Both methods exhibited commendable precision, with a relative standard deviation below 2%. Additionally, recovery rates were acceptable and comparable, ranging from 86.8 to 99.6% for µ-PADs and 96.5–99% for UV–Vis. The analytical performance evaluation suggests that µPADs provide excellent sensitivity, precision, and accuracy for trace-level paracetamol analysis. A paired t-test further confirmed no statistically significant difference between the two methods, underscoring the promising potential of µ-PADs for trace-level paracetamol quantification in water samples without conventional analytical instruments. [ABSTRACT FROM AUTHOR]

Featured Application: The developed methodology enables the rapid fabrication of customized lab-scale reactors, optimizing their design and manufacturing. Beyond desalination, this approach is valuable in the early R&D stages for other electrochemical flow reactors, such as fuel cells, bio-batteries, microfluidic devices, and electrolyzers. In response to the growing demand for potable water, this study presents a practical methodology for designing and fabricating a hybrid desalination system that integrates reverse electrodialysis and electrodialysis using 3D-printing technology. The hybrid system combines the energy generation potential of RED with the salt removal capabilities of ED, reducing energy consumption. Customized reactors were designed to enhance flow distribution and ion exchange, with computational fluid dynamics simulations validating the hydrodynamic performance. The reactors were fabricated using 3D printing, allowing rapid, cost-effective production, with functional reactors constructed in under 24 h. The system achieved a 15% reduction in salt concentration within one hour, with a specific energy consumption of 0.1388 Wh/m3 and a water recovery rate of 50%. These results demonstrate the functionality of the RED-ED hybrid system for achieving energy savings and performing water desalination. This methodology provides a scalable and replicable solution for water treatment applications, especially in regions with abundant salinity gradients and limited freshwater resources, while offering a multidisciplinary approach that integrates physicochemical and engineering principles for effective device development. [ABSTRACT FROM AUTHOR]

Microfluidic devices have revolutionized biosensing by enabling precise manipulation of minute fluid volumes across diverse applications. This review investigates the incorporation of machine learning (ML) into the design, fabrication, and application of microfluidic biosensors, emphasizing how ML algorithms enhance performance by improving design accuracy, operational efficiency, and the management of complex diagnostic datasets. Integrating microfluidics with ML has fostered intelligent systems capable of automating experimental workflows, enabling real-time data analysis, and supporting informed decision-making. Recent advances in health diagnostics, environmental monitoring, and synthetic biology driven by ML are critically examined. This review highlights the transformative potential of ML-enhanced microfluidic systems, offering insights into the future trajectory of this rapidly evolving field. [ABSTRACT FROM AUTHOR]

The editorial in Micromachines discusses the significance of advanced micro- and nano-manufacturing technologies in modern manufacturing. It highlights the applications of these technologies in optimizing surface properties of mechanical components and creating functional materials for various industries. The editorial also presents research articles covering topics such as high-energy/nano/micro advanced manufacturing processes, material post-processing techniques, advanced manufacturing design, simulation, and numerical analysis, as well as advanced detection, monitoring, and intelligent control equipment and methods. The studies featured in the Special Issue contribute to the understanding and development of cutting-edge micro- and nano-manufacturing technologies. [Extracted from the article]

Lab-on-a-chip (LOC) devices have been developed for nucleic acid analysis by integrating complex laboratory functions onto a miniaturized chip, enabling rapid, cost-effective, and highly sensitive on-site testing. This review examines the application of LOC technology in food safety, specifically in the context of nucleic acid-based analyses for detecting pathogens and contaminants. We focus on microfluidic-based LOC devices that optimize nucleic acid extraction and purification on the chip or amplification and detection processes based on isothermal amplification and polymerase chain reaction. We also explore advancements in integrated LOC devices that combine nucleic acid extraction, amplification, and detection processes within a single chip to minimize sample preparation time and enhance testing accuracy. The review concludes with insights into future trends, particularly the development of portable LOC technologies for rapid and efficient nucleic acid testing in food safety. [ABSTRACT FROM AUTHOR]

The advancement of personalized treatments in oncology has garnered increasing attention, particularly for rare and aggressive cancer with low survival rates like the bone tumors osteosarcoma and chondrosarcoma. This study introduces a novel PDMS–agarose microfluidic device tailored for generating patient-derived tumor spheroids and serving as a reliable tool for personalized drug screening. Using this platform in tandem with a custom imaging index, we evaluated the impact of the anticancer agent doxorubicin on spheroids from both tumor types. The device produces 20 spheroids, each around 300 µm in diameter, within a 24 h timeframe, facilitating assessments of characteristics and reproducibility. Following spheroid generation, we measured patient-derived spheroid diameters in bright-field images, calcein AM-positive areas/volume, and the binary fraction area, a metric analyzing fluorescence intensity. By employing a specially developed equation that combines viability signal extension and intensity, we observed a substantial decrease in spheroid viability of around 75% for both sarcomas at the highest dosage (10 µM). Osteosarcoma spheroids exhibited greater sensitivity to doxorubicin than chondrosarcoma spheroids within 48 h. This approach provides a reliable in vitro model for aggressive sarcomas, representing a personalized approach for drug screening that could lead to more effective cancer treatments tailored to individual patients, despite some implementation challenges. [ABSTRACT FROM AUTHOR]

Specialised cells in the blood play an important role in controlling the immune responses. Thus, these cells are also valuable for the diagnosis and treatment of diseases such as autoimmune disorders and cancer. Trace-less Affinity Cell Selection technology, also known as Fab-TACS technology, is a new approach to precisely isolate specific immune cells from blood samples. Currently, this technology is used in a device called Fabian, which resembles a cassette with a capacity of 60 ml. For diagnostic purposes, however, the sample size must be reduced to a few microliters. For this purpose, a stand-alone setup for the control of a microfluidic cartridge was developed and a sequence for the implementation of the TACS technology was designed and characterized. As the combination of cell purification and subsequent cell counting in a single device can streamline workflows and save time, we also integrated an analysis platform for cell counting into the setup. Instead of using two separate devices, isolated samples can be counted immediately after isolation without interruption. This platform was initially tested with latex particles that were passed through the detection channel of the microfluidic cartridge. The functionality of the developed program sequence and cell counting was successfully demonstrated in verification experiments. [ABSTRACT FROM AUTHOR]

“Lung-on-a-chip” (LoC) is a microfluidic device, imitating the gas-fluid interface of the pulmonary alveole in the human lung and intended for pathophysiological, pharmacological and molecular-biological studies of the air-blood barrier in vitro. The LoC device itself contains a system of fluid and gas microchannels, separated with a semipermeable elastic membrane, containing a polymer base and the alveolar cell elements. Depending on the type of LoC (single-, double- and three-channel), the membrane may contain only alveolocytes or alveolocytes combined with other cells — endotheliocytes, fibroblasts, alveolar macrophages or tumor cells. Some LoC models also include proteinic or hydrogel stroma, imitating the pulmonary interstitium. The first double-channel LoC variant, in which one side of the membrane contained an alveolocytic monolayer and the other side — a monolayer of endotheliocytes, was developed in 2010 by a group of scientists from the Harvard University for maximally precise in vitro reproduction of the micro-environment and biomechanics operations of the alveoli. Modern LoC modifications include the same elements and differ only by the construction of the microfluidic system, by the biomaterial of semipermeable membrane, by the composition of cellular and stromal elements and by specific tasks to be solved. Besides the LoC imitating the hematoalveolar barrier, there are modifications for studying the specific pathophysiological processes, for the screening of medicinal products, for modeling specific diseases, for example, lung cancer, chronic obstructive pulmonary disease or asthma. In the present review, we have analyzed the existing types of LoC, the biomaterials used, the methods of detecting molecular processes within the microfluidic devices and the main directions of research to be conducted using the “lung-on-a-chip”.

A novel method combining microfluidic-based synthesis and hyphenated electrospray-differential mobility analysis has been developed for the controlled crosslinking and simultaneous analysis of hydrogels. This approach has been successfully applied to the synthesis of hyaluronic acid hydrogels with precise particle size distributions. [Display omitted] This study presents a novel approach for the controlled synthesis and real-time characterization of crosslinked hyaluronic acid (HA) hydrogels utilizing a microfluidic platform coupled with hyphenated electrospray-differential mobility analysis (ES-DMA). By precisely controlling key synthesis parameters within the microfluidic environment, including pH, temperature, reaction time, and the molar ratio of HA to crosslinker (1,4-butanediol diglycidyl ether, BDDE), we successfully synthesized HA hydrogels with tailored size and properties. The integrated ES-DMA system provides rapid, in-line analysis of hydrogel particle size and distribution, enabling real-time monitoring and optimization of the synthesis process. Furthermore, small-angle x-ray scattering (SAXS) was employed to complement ES-DMA analysis, providing valuable insights into the internal structure and extent of crosslinking within the synthesized hydrogels. The evolution of the number-based particle size distribution revealed a strong correlation with the synthesis conditions, demonstrating the high degree of controllability achieved by this integrated approach. This novel methodology offers a promising platform for the high-throughput synthesis of uniform and well-defined hydrogel nanoparticles with enhanced traceability, paving the way for advancements in various applications including drug delivery, tissue engineering, and biomaterials. [ABSTRACT FROM AUTHOR]

Renal cell carcinoma (RCC) is one of the deadliest malignant tumors. Despite significant advances in RCC treatment over the past decade, complete remission is rarely achieved. Consequently, there is an urgent need to explore and develop new therapies to improve the survival rates and quality of life for patients. In recent years, the development of tumor organoid technology has attracted widespread attention as it can more accurately simulate the spatial structure and physiological characteristics of tumors within the human body. In this review, we summarize the main methods currently used to construct kidney cancer organoids, as well as their various biological and clinical applications. Furthermore, combining organoids with other technologies, such as co-culture techniques and microfluidic technologies, can further develop organoids and address their limitations, creating more practical models. This approach summarizes the interactions between different tissues or organs during tumor progression. Finally, we also provide an outlook on the construction and application of kidney cancer organoids. These rapidly evolving kidney cancer organoids may soon become a focal point in the development of in vitro clinical models and therapeutic research for kidney cancer. [ABSTRACT FROM AUTHOR]

Inflammatory microenvironments often become acidic (pH < 7.4) due to tissue oxygen deprivation and lactate release in glycolysis by activated immune cells. Although neutrophils are known to accumulate in such microenvironments, the effects of pH on their migration are not fully understood. Here, we first investigated the pH control around cultured cells with a microfluidic device, which was equipped with two gas channels above three parallel media channels. By supplying gas mixtures with predefined carbon dioxide (CO2) concentrations to the gas channels, the gas exchange adjusted the dissolved CO2 and affected the chemical equilibrium of sodium hydrogen carbonate in the cell culture medium. A pH gradient from 8.3 to 6.8 was generated along the media channels when gas mixtures containing 1% and 50% CO2 were supplied to the left and right gas channels, respectively. Neutrophil-like differentiated human promyelocytic leukemia cells (HL-60) were then seeded to the fibronectin-coated media channels and their migratory behaviors were quantified while varying the pH. The cell migration became more active and faster under high pH than under low pH conditions. However, no directional migration along the pH gradient was detected during the three-hour observation. Thus, the microfluidic device is useful to elucidate pH-dependent cellular dynamics. [ABSTRACT FROM AUTHOR]

Detecting glucose levels is crucial for diabetes patients as it enables timely and effective management, preventing complications and promoting overall health. In this endeavor, we have designed a novel, affordable point-of-care diagnostic device utilizing microfluidic principles, a smartphone camera, and established laboratory colorimetric methods for accurate glucose estimation. Our proposed microfluidic device comprises layers of adhesive poly-vinyl films stacked on a poly methyl methacrylate (PMMA) base sheet, with micro-channel contours precision-cut using a cutting printer. Employing the gold standard glucose-oxidase/peroxidase reaction on this microfluidic platform, we achieve enzymatic glucose determination. The resulting colored complex, formed by phenol and 4-aminoantipyrine in the presence of hydrogen peroxide generated during glucose oxidation, is captured at various glucose concentrations using a smartphone camera. Raw images are processed and utilized as input data for a 2-D convolutional neural network (CNN) deep learning classifier, demonstrating an impressive 95% overall accuracy against new images. The glucose predictions done by CNN are compared with ISO 15197:2013/2015 gold standard norms. Furthermore, the classifier exhibits outstanding precision, recall, and F1 score of 94%, 93%, and 93%, respectively, as validated through our study, showcasing its exceptional predictive capability. Next, a user-friendly smartphone application named "GLUCOLENS AI" was developed to capture images, perform image processing, and communicate with cloud server containing the CNN classifier. The developed CNN model can be successfully used as a pre-trained model for future glucose concentration predictions. [ABSTRACT FROM AUTHOR]

Simple Summary: Interactions between breast cancer (BCa) cells and carcinoma-associated fibroblasts (CAFs) in the tumor microenvironment (TME) are critical for cancer development and progression and can mitigate responses to therapies. Historically, it has been difficult to replicate in vivo long-term interactions between BCa cells and CAFs for in vitro studies and to define the precise roles of CAFs in BCa cell progression. Our novel microfluidic-capable culture devices called TAME (tissue architecture and microenvironment engineering) devices enable us to study cell-cell interactions of human breast cancer (BCa) cells and human CAFs through their secretome in 3D cultures for extended periods, up to and beyond 70 days. Using these systems, we observed that CAFs enhance BCa cell progression to an invasive phenotype. Moreover, secretome-mediated reciprocal interactions of BCa cells and CAFs promote their migration toward each other, suggesting that targeting signaling pathways to mediate interactions between BCa cells and CAFs could be a potential therapeutic approach for the prevention of BCa progression. Background/Objectives: Carcinoma-associated fibroblasts (CAFs), a prominent cell type in the tumor microenvironment (TME), significantly contributes to cancer progression through interactions with cancer cells and other TME components. Consequently, targeting signaling pathways driven by CAFs has potential to yield new therapeutic approaches to inhibit cancer progression. However, the mechanisms underlying their long-term interactions with cancer cells in vivo remains poorly understood. Methods: To address this, we developed a three-dimensional (3D) parallel coculture model of human triple-negative breast cancer (TNBC) cells and CAFs using our innovative TAME devices. This model allowed for the analysis of TNBC paracrine interactions via their secretome over extended culture periods (at least 70 days). Results: Using TNBC cell lines (MDA-MB-231, MCF10.DCIS, and HCC70), we found that TNBC spheroids in 3D parallel cocultures with CAFs exhibited more pronounced invasive finger-like outgrowths than those in cocultures of TNBC cells and normal fibroblasts (NFs) over a period of 50–70 days. We also established that the CAF-derived secretome affects TNBC migration towards the CAF secretome region. Additionally, we observed a preferential migration of CAFs, but not NFs, toward TNBC spheroids. Conclusions: Overall, our results suggest that paracrine interactions between TNBC cells and CAFs enhance TNBC invasive phenotypes and promote reciprocal migration. [ABSTRACT FROM AUTHOR]

Microfluid-derived liposomes (M-Lipo) exhibit great potential as drug and functional substance carriers in pharmaceutical and food science. However, the low liposome membrane stability, attributed to the liquid core, limits their application range. Oleosin, a natural surfactant protein, can improve the stability of the lipid nanoparticle membrane against various environmental stresses, such as heat, drying, and pH change; in addition, it can enable sustained drug release. Here, we proposed the fabrication of oleosin-coated M-Lipo (OM-Lipo) through self-assembly on a microfluidic chip and the evaluation of its anticancer drug (carmustine) delivery efficiency. Nanoparticle characterization revealed that the oleosin coating slightly lowered the membrane potential of M-Lipo and greatly improved their dispersibility. Additionally, the in vitro drug release profile showed that the oleosin coating improved the sustained release of the hydrophobic drug from the phospholipid bilayer in body temperature. Our results suggest that OM-Lipo has sufficient potential in various fields, based on its easy production, excellent stability, and biocompatibility. [ABSTRACT FROM AUTHOR]

The slow growth and complex life cycle of Haematococcus lacustris pose significant challenges for cost-effective astaxanthin production. This study explores the use of microfluidic collision treatment to stimulate the germination of dormant seed cysts, thereby improving photosynthetic cell growth and astaxanthin productivity in H. lacustris cultivated in well plate and flask cultures. The flow rate (1.0–3.0 mL/min) and the number of T-junction loops (3–30) were optimized in the microfluidic device. Under optimal conditions (a flow rate of 2.0 mL/min with 10 loops), the total cell number density in well plate cultures increased by 44.5% compared to untreated controls, reaching 28.9 ± 2.0 × 104 cells/mL after 72 h. In flask cultures, treated cysts showed a 21% increase in astaxanthin productivity after 30 d, reaching 0.95 mg/L/d, due to higher biomass concentrations, while the astaxanthin content per cell remained constant. However, excessive physical collision stress at higher flow rates and loop numbers resulted in reduced cell viability and cell damage. These findings suggest that carefully controlled cyst mechanostimulation can be an effective and environmentally friendly strategy for Haematococcus biorefining, enabling the production of multiple bioactive products. [ABSTRACT FROM AUTHOR]