Microfluidics and Nanofluidics最新文献

Microfluidic devices have emerged as transformative tools in the field of targeted drug delivery, offering unprecedented precision, efficiency, and control. Patented innovations in microfluidics focus on creating tailored delivery systems capable of overcoming biological barriers, optimizing therapeutic dosing, and minimizing systemic side effects. By integrating advanced materials, microfabrication techniques, and dynamic fluid control, these devices enable localized and sustained release of therapeutics. Applications span oncology, neurology, and chronic disease management, addressing challenges such as drug stability, biodistribution, and cellular targeting. This paper explores patented microfluidic technologies, emphasizing their design principles, functional mechanisms, and their role in revolutionizing drug delivery. Furthermore, we discuss the future prospects and commercialization potential of these devices as key enablers of personalized medicine.

Colorimetric microfluidic paper-based analytical devices (µPADs) offer a promising platform for point-of-care diagnostics due to their simplicity, portability, and low cost. However, their limited dynamic range, typically restricted by a single reagent concentration, often necessitates sample dilution, increasing analysis time and complexity. This work presents a novel strategy to expand the dynamic range of µPADs by integrating varying reagent concentrations within a single device. This approach was demonstrated for the detection of cysteine (Cys), a biomolecule with a wide concentration range in biological and food samples. Indirect Cys quantification was performed by reacting it with Ag(I) prior to the determination of the remaining Ag(I) using K₂CrO₄. Despite the inherent interference from halides in this assay, an integrated online halide removal layer was incorporated into the sensor. Moreover, the interference from other amino acids was not found, indicating high selectivity. A wide linear range of six orders of magnitude (0.0001-10 mg mL^− 1) with a limit of detection of 0.03 µg mL^− 1 was achieved using the multi-concentration approach. The developed µPADs were successfully applied to the analysis of Cys in food samples, achieving high accuracy with recoveries ranging from 87.0 to 107.8%. This innovative approach holds significant potential for enhancing the analytical capabilities of µPADs for various point-of-care applications.

The opportunistic fungus Candida albicans has become the major cause of hospital-acquired infections due to its ability to develop biofilms that resistance to treatments. his study monitored the real-time growth and inhibition of C. albicans hyphal and biofilm formation using optoelectrochemical approaches, focusing on Secreted Aspartyl Protease 5 (SAP5), a key virulence factor. The natural phenolic compound 4-Hydroxyphenylacetic acid (4-HPA) was computationally screened and demonstrated strong binding affinity to SAP5. In vitro studies indicated a minimum biofilm inhibitory concentration (MBIC) of 4 mg/mL and a minimum biofilm eradication concentration (MBEC) of 16 mg/mL. The 4-HPA exhibited considerable potential as an anti-hyphal and anti-biofilm agent, achieving efficacy > 90% in the Biofilm Infection Simulator System (BISS) platform. Likewise, in microfluidic platform, electrochemical analysis revealed 85–90% biofilm inhibition & reduction on MBIC & MBEC doses, respectively. The correlation of microscopic images with electrochemical data revealed complementarity, introducing a novel approach for monitoring microbial biofilms. This study introduces a novel approach to monitoring and treating biofilms, offering promising insights for anti-biofilm drug development.

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The biocompatibility of materials and processes used in the fabrication of three-dimensional (3D) culture devices is crucial for the success of some relevant studies. In this context, 3D printing emerges as a promising technology to be used. This study evaluated three resins as candidates for the production of 3D culture devices: PriZma 3D Bio Splint (resin 1), 3D Prime Premium Cristal (resin 2), and Quanton Spin Skin Opaca (resin 3). Cubic samples of 2 mm and 3 mm were fabricated using a DLP 3D printer, followed by post-processing and sterilization. Biocompatibility was assessed using immortalized BSC-40 cells cultured in 96-well plates using MTT colorimetric assay to estimate cellular viability. A material is considered biocompatible if cell viability is above 70%. Resins 1 and 3 demonstrated high biocompatibility, with cell viability exceeding 80% and no significant differences between sample sizes. In contrast, the cell viability of resin 2 ranged from 60 to 66%. Based on these results, simplified devices for 3D cultures were produced with resin 1, due to its characteristics, particularly its transparency, which facilitates culture protocols and microscopic observations. After 4 days of culture, cells exhibited a three-dimensional morphology with long cellular projections and high viability when evaluated by fluorescence microscopy. We conclude that resins 1 is suitable for device fabrication, while resin 2 and 3 are not recommended because of the low biocompatibility and the opacity. respectively. The chosen materials show great potential for the production of devices for short term 3D cell cultures, an expanding and highly relevant area of scientific research.

The accurate and rapid detection of H1N1 viral specific protein is crucial for effective disease control and management. Traditional diagnostic methods based on ELISA immunoassay often require complex manual operations, long incubation times, and lack the integration needed for automated, high-throughput analysis. There is an urgent demand for a portable, sensitive, integrated, and fully automated diagnostic platform to address these challenges in medical diagnostics. We developed an automated diagnostic system that integrates nanozyme-based detection within a centrifugal microfluidic device for rapid H1N1 viral specific protein detection. The system utilizes nanozymes for signal amplification, leveraging nanozymes to reduce assay times. A high-resolution image sensor and image processing algorithm enable precise interrogation of test results, demonstrating significant improvements in sensitivity. The compact centrifugal microfluidic device automates the sequential delivery of samples, reagents, and nanozyme probes, seamlessly implements mixing, incubation, and liquid transfer. The system achieves a 50-fold sensitivity improvement over the conventional method based on colloidal gold lateral flow strips, with a test time of only 15 min. This work develops a fully automated, integrated diagnostic platform by combining nanozyme-enhanced immunoassay with automatic centrifugal microfluidics. The platform eliminates manual intervention, achieving high sensitivity and rapid detection of infectious disease viral specific protein. Its compact and integrated design makes it a versatile tool for point-of-care diagnostics.

A dripping-regime segmented-flow microfluidic reactor for the continuous production of gold nanoparticles (Au NPs) was designed based on computational fluid dynamics calculations. A flow-focusing junction was applied. Diethyl carbonate (DEC) was used as a green material for the continuous phase. The dispersed aqueous phase consisted of HAuCl₄, NaBH₄, and PVA. Experimental dispersed phase droplet diameter as a function of Capillary number (Ca) corroborated with the CFD calculations. The effect of Ca (0.0013,0.0025 and 0.0050) and pH (1,3 and 11) on HAuCl₄ conversion and Au NPs particle size distribution (PSD) was investigated. Based on nanoparticle tracking analysis (NTA), average particle diameters as small as 1.73 nm with a sharp distribution (standard deviation of 0.27 nm) could be achieved. The apparent pseudo-first-order reduction reaction rate constant was found proportional to the average vorticity within the droplets. Particle growth was not dominated by coalescence processes. No leaching of Au³⁺ by DEC was detected.

In healthcare and industry, infections caused by biofilms and unwanted buildup in the environment are big problems, making it important to have affordable and easy-to-use monitoring tools. The study aims to create an affordable and eco-friendly electrochemical microfluidic device that can easily check biofilm growth without needing invasive methods, making it simpler and cheaper than traditional biosensors. The fabrication of the microfluidic device involved a resource-efficient approach, utilizing 3-D printed molds made from acrylonitrile butadiene styrene material, followed by polydimethylsiloxane casting to form the channels. Screen-printed electrodes (SPEs) were integrated into the device, and acetone washing was used for channel formation. The device performed testing with one bacterial strain (Staphylococcus aureus), one fungal strain (Candida albicans), and two real samples (clinical blood and wastewater) employing impedance methods. Additionally, the study simulated real-world conditions by utilizing clinical and wastewater samples to monitor biofilm growth. Biofilm development in the microfluidic device exhibited a sigmoidal growth pattern, with impedance increases of ~ 74.4% for S. aureus, 73.78% for C. albicans, and 82.7% and 87.34% for clinical and wastewater samples, respectively. High-resolution SEM imaging confirmed the presence of biofilms on the surface of the SPEs. The dynamic range of the device was found to be 1291.57–1811.25 ohms, with a limit of detection of 0.208 CFU/mL and a sensitivity of 10.83 µA/CFU/mL. The device's sustainable fabrication process and reliable performance make it a practical option for researchers with limited resources, offering a valuable alternative to traditional biofilm study methods.

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This study explores the filtration problem of Newtonian, incompressible, and viscous two-dimensional fluid flow through a permeable-walled tube. The generated pressure-driven flow incorporates Darcy’s law at the circular pipe wall. We then apply a transverse magnetic field of uniform strength to control the fluid filtration. Subsequently, we analytically examine the potential impacts of the magnetic field on the magnetohydrodynamic behavior of the fluid particles and the axial pressure field using perturbation analysis. Our results delineate the characteristics of the Lorentz force on the flow and pressure field within the porous-walled pipe. Notably, the magnetically affected pressure changes sign at a specific downstream location within the pipe, while the axial velocity flattens with increasing Hartman number at the inlet. Although the inlet regime is under the well-recognized damping dominance of the magnetic field, the filtration process downstream is accelerated with the assist of it.

Microelectromechanical systems (MEMS) have significantly advanced biomedical applications, enabling precise control in cell culture, tissue engineering, and drug delivery by creating highly controlled microenvironments that mimic biological systems. Traditional approaches to diagnostics and tissue fabrication face challenges in precision and scalability, driving interest in MEMS-based biosensors and microfluidic devices. These technologies offer high-throughput analysis and cellular manipulation, essential for developing complex three-dimensional (3D) tissue constructs. This paper reviews advancements in MEMS biocompatibility assessment over the past 14 years (2011–2024), focusing on material selection and device design to meet regulatory and performance standards. It also evaluates in vitro and in vivo testing methods, addressing unique challenges posed by MEMS-specific characteristics such as micro-scale structures and mixed materials. Finally, this paper highlights future directions for enhancing biocompatibility, safety, and performance, paving the way for the integration of MEMS into clinical applications to address critical challenges in biomedical fields.