Biomedical Microdevices最新文献

Microfluidic chips often face challenges related to the formation and accumulation of air bubbles, which can hinder their performance. This study investigated a bubble trapping mechanism integrated into microfluidic chip to address this issue. Microfluidic chip design includes a high shear stress section of fluid flow that can generate up to 2.7 Pa and two strategically placed bubble traps. Commercially available magnets are used for fabrication, effectively reducing production costs. The trapping efficiency is assessed through video recordings with a phone camera and analysis of captured air volumes by injecting dye at flow rates of 50, 100, and 150 µL/min. This assessment uses L*A*B* color space with analysis of the perceptual color difference ∆E and computational fluid dynamics (CFD) simulations. The results demonstrate successful application of the bubble trap mechanism for lab-on-chip bubble detection, effectively preventing bubbles from entering microchannels and mitigating potential damage. Furthermore, the correlation between the L*A*B* color space and volume fraction from CFD simulations allows accurate assessment of trap performance. Therefore, this observation leads to the hypothesis that ∆E could be used to estimate the air volume inside the bubble trap. Future research will validate the bubble trap performance in cell cultures and develop efficient methods for long-term air bubble removal.

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Wearable and implantable biosensors have rapidly entered the fields of health and biomedicine to diagnose diseases and physiological monitoring. The use of wired medical devices causes surgical complications, which can occur when wires break, become infected, generate electrical noise, and are incompatible with implantable applications. In contrast, wireless power transfer is ideal for biosensing applications since it does not necessitate direct connections between measurement tools and sensing systems, enabling remote use of the biosensors. In addition, wireless sensors eliminate the need for a battery or energy harvester, reducing the size of the sensor. As far as we are aware, this is the first report ever describing a new method for wireless readout of a label-free electronic biosensor for detecting protein biomarkers. Our results reveal that we are able to successfully detect target protein and corresponding antibodies within this wireless setup. We are able to distinguish target protein in purified samples from a blank PBS sample as a negative control by tracking gradual changes in impedance at the input of the transmitter (P-value = 0.00788). We also demonstrate real-time wireless quantification of cytokines within rheumatoid arthritis patient serum samples (P-value = 0.00891). A Fine Gaussian Support Vector Machine is also used to differentiate protein from negative controls with the highest accuracy from a dataset of 54 experiments.

Intravenous drug administration delivers medication directly into the bloodstream, providing rapid and controlled effects, making it highly beneficial for emergencies or when immediate drug action is required. However, several risks are associated with intravenous drug administration, including infiltration and extravasation, which can lead to serious complications due to the rapid absorption of medication to the surrounding tissues. To prevent complications, here we proposed a non-contact sensor module to rapidly detect such events. The system does not interfere with the human skin, nor contaminating the flowing medication since only biocompatible materials are exposed to the liquid. The proposed sensor module was assembled as a flow channel with flow rate and pressure sensing functions. The flow rate sensing was realized using a micromachined thermal flow sensor fabricated on a thin polyimide film, while the pressure sensing was realized using a diaphragm structure and a MEMS pressure sensor. Basic characteristics of each function was evaluated and a proof of concept experiment demonstrated a rapid detection of infiltration/extravasation within a few s. Measurement of leaked fluid volume during the event was also demonstrated.

The broad availability of smartphones has provided new opportunities to develop less expensive, portable, and integrated point-of-care (POC) platforms. Here, a platform that consists of three main components is introduced: a portable housing, a centrifugal microfluidic disc, and a mobile phone. The mobile phone supplies the electrical power and serves as an analysing system. The low-cost housing made from cardboard serves as a platform to conduct tests. The electrical energy stored in mobile phones was demonstrated to be adequate for spinning a centrifugal disc up to 3000 revolutions per minute (RPM), a rotation speed suitable for majority of centrifugal microfluidics-based assays. For controlling the rotational speed, a combination of magnetic and acoustic tachometry using embedded sensors of the mobile phone was used. Experimentally, the smartphone-based tachometry was proven to be comparable with a standard laser-based tachometer. As a proof of concept, two applications were demonstrated using the portable platform: a colorimetric sandwich immunoassay to detect interleukin-2 (IL-2) having a limit of detection (LOD) of 65.17 ng/mL and a fully automated measurement of hematocrit level integrating blood-plasma separation, imaging, and image analysis that takes less than 5 mins to complete. The low-cost platform weighing less than 150 g and operated by a mobile phone has the potential to meet the REASSURED criteria for advanced diagnostics in resource limited settings.

Biomedical imaging plays a critical role in early detection, precise diagnosis, treatment planning, and monitoring responses, but traditional methods encounter challenges such as limited sensitivity, specificity, and inability to monitor therapeutic responses due to factors like short circulation half-life and potential toxicity. Nanoparticles are revolutionizing biomedical imaging as contrast agents across modalities like computed tomography (CT), optical, magnetic resonance imaging (MRI), and ultrasound, exploiting unique attributes such as those of metal-based, polymeric, and lipid nanoparticles. They shield imaging agents from immune clearance, extending circulation time, and enhancing bioavailability at tumor sites. This results in improved imaging sensitivity. The study highlights advancements in multifunctional nanoparticles for targeted imaging, tackling concerns regarding toxicity and biocompatibility. Critically evaluating conventional contrast agents, emphasizes the shortcomings that nanoparticles aim to overcome. This review provides insight into the current status of nanoparticle-based contrast agents, illuminating their potential to reshape therapeutic monitoring and precision diagnostics.

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Transdermal drug delivery (TDD) has significantly advanced medical practice in recent years due to its ability to prevent the degradation of substances in the gastrointestinal tract and avoid hepatic metabolism. Among different available approaches, microneedle arrays (MNAs) technology represents a fascinating delivery tool for enhancing TDD by penetrating the stratum corneum painless and minimally invasive for delivering antibacterial, antifungal, and antiviral medications. Polymeric MNAs are extensively utilized among many available materials due to their biodegradability, biocompatibility, and low toxicity. Therefore, this review provides a comprehensive discussion of polymeric MNAs, starting with understanding stratum corneum and developing MNA technology. Furthermore, the engineering concepts, fundamental considerations, challenges, and future perspectives of polymeric MNAs in clinical applications are properly outlined, offering a comprehensive and unique overview of polymeric MNAs and their potential for a broad spectrum of clinical applications.

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The utilization of existing Skin-on-a-Chip (SoC) is constrained by the complex structures, the multiplicity of auxiliary devices, and the inability to evaluate exogenous chemicals that are hepatotoxic after percutaneous metabolism. In this study, a gravity-driven SoC without any auxiliary devices was constructed for the hepatocytotoxicity study of exogenous chemicals. The SoC possesses 3 layers of culture chambers, from top to bottom, for human skin equivalent (HSE), Human Umbilical Vein Endothelial Cells (HUVEC) and hepatocytes (HepG2), and the maintenance and expression capacity of the corresponding cells on the SoC were verified by specificity parameters. The reactivity of the SoC to exogenous chemicals was verified by 2-aminofluorene (2-AF). The SoC can realistically simulate the in vivo exposure process of exogenous chemicals that are percutaneously exposed and metabolized into the bloodstream and then to the liver to produce toxicity, and it can achieve the same effects on transcriptome as those of animal tests at lower exposure levels while examining multiple toxicological targets of the skin, vascular endothelial cells, and hepatocytes. Both in terms of species similarity, the principles of reduction, replacement and refinement (3R), or the level of exposure suggest that the present SoC has a degree of replacement for animal models in assessing exogenous chemicals, especially those that are hepatotoxic after percutaneous metabolism.

Microbubbles are widely used for biomedical applications, ranging from imagery to therapy. In these applications, microbubbles can be functionalized to allow targeted drug delivery or imaging of the human body. However, functionalization of the microbubbles is quite difficult, due to the unstable nature of the gas/liquid interface. In this paper, we describe a simple protocol for rapid functionalization of microbubbles and show how to use them inside a microfluidic chip to develop a novel type of biosensor. The microbubbles are functionalized with biochemical ligand directly at their generation inside the microfluidic chip using a DSPE-PEG-Biotin phospholipid. The microbubbles are then organized inside a chamber before injecting the fluid with the bioanalyte of interest through the static bubbles network. In this proof-of-concept demonstration, we use streptavidin as the bioanalyte of interest. Both functionalization and capture are assessed using fluorescent microscopy thanks to fluorescent labeled chemicals. The main advantages of the proposed technique compared to classical ligand based biosensor using solid surface is its ability to rapidly regenerate the functionalized surface, with the complete functionalization/capture/measurement cycle taking less than 10 min.