Carbon nanotube-based thin-film resistive sensor for point-of-care screening of tuberculosis.
Abstract For point-of-care diagnosis of tuberculosis (TB), current TB diagnostic approaches need to be further improved for achieving an accurate diagnosis that is rapid and low-cost. This paper presents an immuno-resistive sensor on a plastic film for inexpensive, simple TB screening. The sensor is composed of single-walled carbon nanotubes (SWCNTs) functionalized with polyclonal antibodies raised against the MPT64 surface antigen from Mycobacterium tuberculosis (MTB). The target analyte of either MTB or MPT64 is spiked in tongue swab and sputum samples. Under optimized conditions, targets are directly detected f...
Source: Biomedical Microdevices - July 28, 2020 Category: Biomedical Engineering Authors: Kahng SJ, Soelberg SD, Fondjo F, Kim JH, Furlong CE, Chung JH Tags: Biomed Microdevices Source Type: research

Hydrogel-based sealed microchamber arrays for rapid medium exchange and drug testing of cell spheroids.
Abstract Culturing cell spheroids in microchamber arrays is a widely used method in regenerative medicine and drug discovery while it requires laborious procedures during medium exchange and drug administration. Here, we report a simple method for the medium exchange and drug testing using a hydrogel-based sealed microchamber arrays. Owing to the high molecular permeability of poly(vinyl alcohol) hydrogel, the sealed microchamber allows nutrients and drugs in outer medium to pass through. Thus, automatic medium exchange and drug testing for all the cell spheroids inside the microchamber arrays are achieved by simp...
Source: Biomedical Microdevices - July 27, 2020 Category: Biomedical Engineering Authors: Yoshida S, Sumomozawa K, Nagamine K, Nishizawa M Tags: Biomed Microdevices Source Type: research

Microfluidic Chip based direct triple antibody immunoassay for monitoring patient comparative response to leukemia treatment.
We report a time and cost-efficient microfluidic chip for screening the leukemia cells having three specific antigens. In this method, the target blast cells are double sorted with immunomagnetic beads and captured by the 3rd antibody immobilized on the gold surface in a microfluidic chip. The captured blast cells in the chip were imaged using a bright-field optical microscope and images were analyzed to quantify the cells. First sorting was performed with nano size immunomagnetic beads and followed by 2nd sorting where micron size immunomagnetic beads were used. The low-cost microfluidic platform is made of PMMA and glass...
Source: Biomedical Microdevices - July 13, 2020 Category: Biomedical Engineering Authors: İçöz K, Akar Ü, Ünal E Tags: Biomed Microdevices Source Type: research

A hybrid electrically-and-piezoelectrically driven micromixer built on paper for microfluids mixing.
This study aims to explore the channel patterns and the characteristic parameters of the zigzag microchannel based on microfluidic paper-based analytical devices (μPADs), in which the mixing efficiency and speed can be greatly enhanced. Better mixing of the solutions was obtained by adding a simple directing electric field to the optimized structure of the zigzag microchannel on paper-based chips instead of the traditional complex devices. A higher mixing efficiency was reached when the direct-current (DC) power supply reached 20 V. Meanwhile, a piezoelectric transducer (PZT) driver was used in the mixing experimen...
Source: Biomedical Microdevices - July 8, 2020 Category: Biomedical Engineering Authors: Guan Y, Xu F, Sun B, Meng X, Liu Y, Bai M Tags: Biomed Microdevices Source Type: research

Vitreous protein binding with nanopore dialysis membrane device.
In this study, we tested a novel approach by dialyzing proteins from the vitreous using biocompatible implants composed of a nanopore polyacrylonitrile polymer membrane. Preliminary in vitro and in vivo studies demonstrate a high affinity and capacity for complement protein absorption. After a three-month implantation in New Zealand White Cross rabbits, the implant demonstrated good biocompatibility with no inflammation and normal retinal physiology and histology. These studies demonstrate that prolonged CF suppression intraocularly may be accomplished with a nanopore polymer membrane. PMID: 32623529 [PubMed - in proc...
Source: Biomedical Microdevices - July 4, 2020 Category: Biomedical Engineering Authors: Olson JL, Velez-Montoya R, Mackin A, Manoharan N, Mueller N, Erlanger M Tags: Biomed Microdevices Source Type: research

Label free Impedimetric Immunosensor for effective bladder Cancer detection in clinical urine samples.
Abstract Galectin-1 protein has been recently recognized as a valuable urinary biomarker for the diagnosis and prognosis of bladder cancer. Herein, we present a sensitive and specific impedimetric immunosensor for the quantitative and label free detection of Galectin-1 protein in clinical urine samples. The immunosensor consists of nine gold interdigitated microelectrodes (3 × 3 array), which can simultaneously monitor multiple immunoreactions by analyzing the normalized impedance variations at each microelectrode during immunosensing. To obtain enhanced sensitivities, we have utilized Galectin...
Source: Biomedical Microdevices - June 30, 2020 Category: Biomedical Engineering Authors: Shaikh MO, Huang TC, Wu TF, Chuang CH Tags: Biomed Microdevices Source Type: research

Poly-L-histidine coated microfluidic devices for bacterial DNA purification without chaotropic solutions.
We present a disposable polymeric microfluidic device capable of reversibly binding and purifying Salmonella DNA through solid phase extraction (SPE). The microfluidic channels are first oxygen plasma treated and simultaneously micro-nanotextured, and then functionalized with amine groups via modification with L-histidine or poly-L-histidine. L-Histidine and poly-L-histidine bind on the plasma treated chip surface, and are not detached when rinsing with DNA purification protocol buffers. A pH-dependent protocol is applied on-chip to purify Salmonella DNA, which is first bound on the protonated amines at a pH (5.0) lower th...
Source: Biomedical Microdevices - June 22, 2020 Category: Biomedical Engineering Authors: Kastania AS, Petrou PS, Loukas CM, Gogolides E Tags: Biomed Microdevices Source Type: research

Penetrating glassy carbon neural electrode arrays for brain-machine interfaces.
Abstract This paper presents a fabrication method for glassy carbon neural electrode arrays that combines 3D printing and chemical pyrolysis technology. The carbon electrodes have excellent biological compatibility and can be used in neural signal recording. A pretreated Si wafer is used as the substrate for 3D printing, and then, stereolithography 3D printing technology is employed to print photosensitive resin into a cone shape. Next, chemical pyrolysis is applied to convert the 3D prints into glassy carbon electrodes and modify the electrochemical performance of the carbon electrodes. Finally, the glassy carbon...
Source: Biomedical Microdevices - June 6, 2020 Category: Biomedical Engineering Authors: Chen B, Zhang B, Chen C, Hu J, Qi J, He T, Tian P, Zhang X, Ni G, Cheng MM Tags: Biomed Microdevices Source Type: research

Covalent immobilization of luminescent oxygen indicators reduces cytotoxicity.
Narkilahti S, Lekkala J Abstract Luminescence-based oxygen sensing is a widely used tool in cell culture applications. In a typical configuration, the luminescent oxygen indicators are embedded in a solid, oxygen-permeable matrix in contact with the culture medium. However, in sensitive cell cultures even minimal leaching of the potentially cytotoxic indicators can become an issue. One way to prevent the leaching is to immobilize the indicators covalently into the supporting matrix. In this paper, we report on a method where platinum(II)-5,10,15,20-tetrakis-(2,3,4,5,6-pentafluorphenyl)-porphyrin (PtTFPP) oxygen in...
Source: Biomedical Microdevices - June 3, 2020 Category: Biomedical Engineering Authors: Välimäki H, Hyvärinen T, Leivo J, Iftikhar H, Pekkanen-Mattila M, Rajan DK, Verho J, Kreutzer J, Ryynänen T, Pirhonen J, Aalto-Setälä K, Kallio P, Narkilahti S, Lekkala J Tags: Biomed Microdevices Source Type: research

Effect of angle-of-attacks on deterministic lateral displacement (DLD) with symmetric airfoil pillars.
Abstract Deterministic lateral displacement (DLD) is a microfluidic technique for size fractionation of particles/cells in continuous flow with a great potential for biological and clinical applications. Growing interest of DLD devices in enabling high-throughput operation for practical applications, such as circulating tumor cell (CTC) separation, necessitates employing higher flow rates, leading to operation at moderate to high Reynolds number (Re) regimes. Recently, it has been shown that symmetric airfoil shaped pillars with neutral angle-of-attack (AoA) can be used for high-throughput design of DLD devices du...
Source: Biomedical Microdevices - June 3, 2020 Category: Biomedical Engineering Authors: Ahasan K, Landry CM, Chen X, Kim JH Tags: Biomed Microdevices Source Type: research

High-throughput cell migration assay under combinatorial chemical environments by a novel 24-well-plate based device.
In this study, we developed a new device to pattern several types of cells in 24-well-plate and demonstrated its' application in cancer cell proliferation and migration assay. The new device combined 3D-printed-silica-part for multi cell types loading with PDMS-through-hole-layer-part for cell micro-patterning which was matched with commercial 24-well-plate. This 24-well-plate based device is flexible and feasible in many applications and can be used in one piece or multi pieces. Besides the application for two types of cells proliferation and migration assay in one chemical condition, as a demonstration, the migration beh...
Source: Biomedical Microdevices - May 30, 2020 Category: Biomedical Engineering Authors: Xu J, Wang X, Li X, Yang G, Luo C Tags: Biomed Microdevices Source Type: research

An immunoassay cassette with a handheld reader for HIV urine testing in point-of-care diagnostics.
Abstract Currently, most HIV tests are performed with blood samples, or alternatively saliva samples are used for HIV testing. Simple HIV tests need to be performed in hospitals or other medical agencies instead of more invasive HIV blood tests. To enable point-of-care (POC) HIV diagnostics, based on a recently developed lateral flow strip for HIV urine testing, a microfluidic immunoassay cassette with a handheld optical reader is developed. Based on lateral flow strip with gold colloid reporter, the integrated immunoassay cassette can perform sample introduction, metering, discharging, applying and detection whic...
Source: Biomedical Microdevices - May 21, 2020 Category: Biomedical Engineering Authors: Yang W, Yang D, Gong S, Dong X, Liu L, Yu S, Zhang X, Ge S, Wang D, Xia N, Yu D, Qiu X Tags: Biomed Microdevices Source Type: research

On-chip estimation of hematocrit level for diagnosing anemic conditions by Impedimetric techniques.
Abstract An on-chip device has been fabricated on Si platform for precise estimation of the hematocrit (Hct) level of human blood with rapid turn out. Impedance/capacitance spectroscopy and current-voltage (I-V) measurements have been employed to observe the variation of electrical parameters of erythrocyte suspensions with varying Hct level. Experimentally obtained values of capacitance, impedance and conductance with Hct level suggests a linear variation. Current-time measurement has also been performed to ensure the susceptibility of red blood cells under a fixed external electric field for certain duration of ...
Source: Biomedical Microdevices - May 20, 2020 Category: Biomedical Engineering Authors: Chakraborty S, Das S, Das C, Chandra S, Sharma KD, Karmakar A, Chattoapadhyay S Tags: Biomed Microdevices Source Type: research

3D-Printed micro-optofluidic device for chemical fluids and cells detection.
Abstract In this work, it is presented a micro-optofluidic flow detector used for on-chip biological and chemical samples investigation. It is made in Poly-dimethyl-siloxane using a master-slave approach based on the 3D-Printing techniques. The micro-optofluidic device is made by assembling a microfluidic T-junction with a micro-optical section that consists of two optical fiber insertions and a PDMS gold-spattered micro-waveguide. The working principle in the detection is based on a different light transmission correlated to the fluid interfering with the laser beam in a micro-channel section. The proposed soluti...
Source: Biomedical Microdevices - May 18, 2020 Category: Biomedical Engineering Authors: Cairone F, Davi S, Stella G, Guarino F, Recca G, Cicala G, Bucolo M Tags: Biomed Microdevices Source Type: research

Simultaneous electrical detection of IL-6 and PCT using a microfluidic biochip platform.
Abstract Sepsis, a life-threatening organ dysfunction caused by a dysregulated host response, leads the U.S in both mortality rate and cost of treatment. Sepsis treatment protocols currently rely on broad and non-specific parameters like heart and respiration rate, and temperature; however, studies show that biomarkers Interlukin-6 (IL-6) and Procalcitonin (PCT) correlate to sepsis progression and response to treatment. Prior work also suggests that using multi-parameter predictive analytics with biomarkers and clinical information can inform treatment to improve outcome. A point-of-care (POC) platform that provid...
Source: Biomedical Microdevices - May 18, 2020 Category: Biomedical Engineering Authors: Berger J, Valera E, Jankelow A, Garcia C, Akhand M, Heredia J, Ghonge T, Liu C, Font-Bartumeus V, Oshana G, Tiao J, Bashir R Tags: Biomed Microdevices Source Type: research

Development and characterization of a PDMS-based masking method for microfabricated Oral drug delivery devices.
Abstract With the growing popularity and application of microfabricated devices in oral drug delivery (ODD), masking technologies for drug loading and surface modification become highly relevant. Considering the speed of design and fabrication processes and the necessity for continuous alterations of e.g. the shape and sizes of the devices during the optimization process, there is a need for adaptable, precise and low-cost masking techniques. Here, a novel method is presented for masking ODD microdevices, namely microcontainers, using the physical characteristics of polydimethylsiloxane (PDMS). When compared to a ...
Source: Biomedical Microdevices - May 18, 2020 Category: Biomedical Engineering Authors: Kamguyan K, Thamdrup LHE, Vaut L, Nielsen LH, Zor K, Boisen A Tags: Biomed Microdevices Source Type: research

Biomimetic aorta-gonad-Mesonephros-on-a-Chip to study human developmental hematopoiesis.
Abstract A fundamental limitation in the derivation of hematopoietic stem and progenitor cells is the imprecise understanding of human developmental hematopoiesis. Herein we established a multilayer microfluidic Aorta-Gonad-Mesonephros (AGM)-on-a-chip to emulate developmental hematopoiesis from pluripotent stem cells. The device consists of two layers of microchannels separated by a semipermeable membrane, which allows the co-culture of human hemogenic endothelial (HE) cells and stromal cells in a physiological relevant spatial arrangement to replicate the structure of the AGM. HE cells derived from human induced ...
Source: Biomedical Microdevices - May 6, 2020 Category: Biomedical Engineering Authors: Sugimura R, Ohta R, Mori C, Li A, Mano T, Sano E, Kosugi K, Nakahata T, Niwa A, Saito MK, Torisawa YS Tags: Biomed Microdevices Source Type: research

Optical measurement platform of temperature-dependent interaction between nanoliposomes and a polymer-grafted surface.
In this study, we report an opto-microfluidic platform integrated with dark-field light scattering imaging and fluorescence microspectroscopy to investigate the temperature-dependent behavior of nanoliposomes. This newly developed experimental platform enabled both in situ measurements of the temperature of the sample solution and observation of individual nanoliposomes. As a proof-of-concept, the temperature-dependent interaction between 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) nanoliposomes and a poly(ethylene glycol) (PEG) grafted surface was investigated using this opto-microfluidic platform. Temperature-depend...
Source: Biomedical Microdevices - May 4, 2020 Category: Biomedical Engineering Authors: Majarikar V, Takehara H, Ichiki T Tags: Biomed Microdevices Source Type: research

Rapid lipid bilayer membrane formation on Parylene coated apertures to perform ion channel analyses.
We present a chip design allowing rapid and robust lipid bilayer (LBL) membrane formation using a Parylene coated thin silicon nitride aperture. After bilayer formation, single membrane channels can be reconstituted and characterized by electrophysiology. The ability for robust reconstitution will allow parallelization and enhanced screening of small molecule drugs acting on or permeating across the membrane channel. The aperture was realized on a microfabricated silicon nitride membrane by using standard clean-room fabrication processes. To ensure the lipid bilayer formation, the nitride membrane was coated with a hydroph...
Source: Biomedical Microdevices - April 30, 2020 Category: Biomedical Engineering Authors: Ahmed T, van den Driesche S, Bafna JA, Oellers M, Hemmler R, Gall K, Wagner R, Winterhalter M, Vellekoop MJ Tags: Biomed Microdevices Source Type: research

Breast Tumor Targeting with PAMAM-PEG-5FU-99mTc As a New Therapeutic Nanocomplex: In In-vitro and In-vivo studies.
Abstract Dendrimer-based targeted drug delivery, as an innovative polymeric drug-delivery system, is promising for cancer therapy. Folate receptors (FR) are overexpressed in many types of tumor cells, such as breast cell carcinomas, which allow folate-targeted delivery. Therefor polyethylene glycol (PEG) modified-PAMAM G4 dendrimers were functionalized with folic acid (FA), as targeting agent. Then, 5-FU (5-fluorouracil) and 99mTc (technetium-99 m) as therapeutic agents were respectively loaded and conjugated to previous nano-complex (PEG-PAMAM G4-FA-5FU-99mTc). The value of drug loading was calculated by TGA...
Source: Biomedical Microdevices - April 25, 2020 Category: Biomedical Engineering Authors: Narmani A, Arani MAA, Mohammadnejad J, Vaziri AZ, Solymani S, Yavari K, Talebi F, Darzi SJ Tags: Biomed Microdevices Source Type: research

Interdigitated aluminium and titanium sensors for assessing epithelial barrier functionality by electric cell-substrate impedance spectroscopy (ECIS).
Abstract Electric cell-substrate impedance spectroscopy (ECIS) enables non-invasive and continuous read-out of electrical parameters of living tissue. The aim of the current study was to investigate the performance of interdigitated sensors with 50 μm electrode width and 50 μm inter-electrode distance made of gold, aluminium, and titanium for monitoring the barrier properties of epithelial cells in tissue culture. At first, the measurement performance of the photolithographic fabricated sensors was characterized by defined reference electrolytes. The sensors were used to monitor the electrical prop...
Source: Biomedical Microdevices - April 24, 2020 Category: Biomedical Engineering Authors: Schmiedinger T, Partel S, Lechleitner T, Eiter O, Hekl D, Kaseman S, Lukas P, Edlinger J, Lechner J, Seppi T Tags: Biomed Microdevices Source Type: research

Detection of renal biomarkers in chronic kidney disease using microfluidics: progress, challenges and opportunities.
Abstract Chronic kidney disease (CKD) typically evolves over many years in a latent period without clinical signs, posing key challenges to detection at relatively early stages of the disease. Accurate and timely diagnosis of CKD enable effective management of the disease and may prevent further progression. However, long turn-around times of current testing methods combined with their relatively high cost due to the need for established laboratory infrastructure, specialized instrumentation and trained personnel are drawbacks for efficient assessment and monitoring of CKD, especially in underserved and resource-p...
Source: Biomedical Microdevices - April 22, 2020 Category: Biomedical Engineering Authors: Liu KZ, Tian G, Ko AC, Geissler M, Brassard D, Veres T Tags: Biomed Microdevices Source Type: research

Highly sensitive vertical flow based point-of-care immunokit for rapid and early detection of human CRP as a cardiovascular risk factor.
Abstract Early detection and treatment of cardiovascular disease by identifying markers is important to improve the health of our citizens and simultaneously reduce the cost of health care. Therefore, there is an urgent need for early detection and treatment of asymptomatic cardiovascular disease. Herein, we have developed highly sensitive vertical flow immunokit (VFIK) for the detection of C-reactive protein (CRP), comprising an antibody/citrate conjugated gold nanoparticle in a fixed orientation surface. Our CRP test kit has been optimized with various parameters such as buffer composition, the quantity of captu...
Source: Biomedical Microdevices - March 28, 2020 Category: Biomedical Engineering Authors: Prajapati A, Verma N, Pandya A Tags: Biomed Microdevices Source Type: research

Hydrodynamic flow cytometer performance enhancement by two-dimensional acoustic focusing.
Abstract Conventional flow cytometers employ hydrodynamic focusing method to insure detection accuracy by forcing cells go through detected position. However, an increased flow velocity will significantly reduce detection precision due to a fact that cells will deviate center position and are easily silted in choke point. In an effort to overcome this limitation, a two-dimension ultrasonic particle focusing method are presented in this work to enhance the performance of flow cytometer. Two piezoelectric transducers are used to attach to a 250 μm × 250 μm rectangular fused silica...
Source: Biomedical Microdevices - March 28, 2020 Category: Biomedical Engineering Authors: Li Z, Li P, Xu J, Shao W, Yang C, Cui Y Tags: Biomed Microdevices Source Type: research

Development of a wireless accelerometer-based Intravaginal device to detect pelvic floor motion for evaluation of pelvic floor dysfunction.
Abstract Urinary incontinence (UI) is experienced by an estimated 51% of women in the U.S. and often results from impaired function or weakening of the pelvic floor muscles. Pelvic floor muscle training (PFMT) is a frontline nonsurgical treatment, yet a number of symptomatic individuals cannot accurately perform a pelvic floor muscle contraction with simple verbal or written instruction. Long-term adherence to PFMT regimens is often a barrier to resolution of symptoms. Various biofeedback tools have been utilized to aid correct pelvic floor muscle performance and adherence. One novel device, the leva® Pelvic D...
Source: Biomedical Microdevices - March 17, 2020 Category: Biomedical Engineering Authors: Bohorquez J, McKinney J, Keyser L, Sutherland R, Pulliam SJ Tags: Biomed Microdevices Source Type: research

Biological and antibacterial properties of TiO2 coatings containing Ca/P/Ag by one-step and two-step methods.
Abstract The porous TiO2 coatings containing Ca/P/Ag were separately prepared on titanium (Ti) surface by one-step (micro-arc oxidation) and two-step methods (micro-arc oxidation and cathodic deposition), and then their surface morphology, composition, biological and antibacterial properties were compared. The results showed that the porous coatings containing Ca/P/Ag achieved by different methods showed similar surface morphology and elemental composition, however, by one-step method, silver existed in the coating as silver phosphate, while in the coatings prepared by two-step method, silver existed as metallic s...
Source: Biomedical Microdevices - March 12, 2020 Category: Biomedical Engineering Authors: Zhang L, Li B, Zhang X, Wang D, Zhou L, Li H, Liang C, Liu S, Wang H Tags: Biomed Microdevices Source Type: research

Enhanced chromosome extraction from cells using a pinched flow microfluidic device.
Abstract Extraction and purification of intact chromosomes are critical sample preparation steps for transchromosomic research and other applications. The commonly used sample preparation methods lead to too few chromosomes with chromosome deactivation and degradation. In this paper, a "mild" chromosome extraction process that combines a chemical and mechanical lysis approach is introduced for the preparation of intact chromosomes that can readily be used for downstream processing. Metaphase cells are treated by chemical lysis buffer and pushed through a microfluidic pinched flow device. Cells are ruptur...
Source: Biomedical Microdevices - March 12, 2020 Category: Biomedical Engineering Authors: Feng H, Hockin M, Zhang S, Capecchi M, Gale B, Sant H Tags: Biomed Microdevices Source Type: research

Isolation and mutational assessment of pancreatic cancer extracellular vesicles using a microfluidic platform.
Abstract Cancer cells release extracellular vesicles known as extracellular vesicles (EVs), containing tumor-derived DNA, RNA and proteins within their cargo, into the circulation. Circulating tumor-derived extracellular vesicles (TEV) can be used in the context of serial "liquid biopsies" for early detection of cancer, for monitoring disease burden in patients, and for assessing recurrence in the post-resection setting. Nonetheless, isolating sufficient TEV by ultracentrifugation-based approaches, in order to enable molecular assessment of EVs cargo, can be an arduous, time-consuming process and is inco...
Source: Biomedical Microdevices - March 11, 2020 Category: Biomedical Engineering Authors: Kamyabi N, Abbasgholizadeh R, Maitra A, Ardekani A, Biswal SL, Grande-Allen KJ Tags: Biomed Microdevices Source Type: research

Enzymatically functionalized polyaniline thin films produced with one-step electrochemical immobilization and its application in glucose and urea potentiometric biosensors.
Abstract Glucose and urea enzymatic biosensors were fabricated. One-step electrochemical immobilization process was used to produce thin polyaniline films with entrapped enzymes. Chronopotentiometric analysis, scanning electron microscopy, electrochemical impedance spectroscopy and optical reflectance spectroscopy were used to determine the structure-property relationship of the functionalized polymeric thin films. The device has a recognition stage connected to a potentiometric field-effect-transistor stage and is based on the measurement of microenvironment pH variation or locally produced ions. Optimization of ...
Source: Biomedical Microdevices - February 27, 2020 Category: Biomedical Engineering Authors: Mello HJNPD, Mulato M Tags: Biomed Microdevices Source Type: research

Posture related in-vitro characterization of a flow regulated MEMS CSF valve.
Abstract Overdrainage in upright position is one of the most prevalent issues in treating hydrocephalus with a cerebrospinal fluid (CSF) shunt. Anti-siphon devices (ASDs) are employed to reduce this problem. A novel microelectromechanical system (MEMS)-based valve, termed Chronoflow device, aims to regulate CSF drainage indifferently of the body posture. With this study, the suitability of this MEMS-based valve is evaluated regarding its use for the treatment of hydrocephalus, particularly for the prevention of overdrainage and blockage. In total, four Chronoflow devices were tested. An established in-vitro hardwa...
Source: Biomedical Microdevices - February 22, 2020 Category: Biomedical Engineering Authors: Tachatos N, Chappel E, Dumont-Fillon D, Meboldt M, Daners MS Tags: Biomed Microdevices Source Type: research

Cell trapping microfluidic chip made of Cyclo olefin polymer enabling two concurrent cell biology experiments with long term durability.
Abstract Cyclo Olefin Polymer (COP) based microbioreactors on a microfluidic chip were produced in house by hot-embossing and thermo-compression bonding methods. The chip allows two different experiments to be performed on trapped cells at the same time. On one side of the chip, red fluorescent protein (RFP) tagged nucleolar Nop56 protein was used to track changes in cell cycle as well as protein synthesis within the yeast cells under the application of the anti-tumor agent hydroxyurea (HU). Simultaneously, on the other side of the chip, the response of yeast cells to the drug metformin, mTOR inhibitor, was invest...
Source: Biomedical Microdevices - February 20, 2020 Category: Biomedical Engineering Authors: Gencturk E, Yurdakul E, Celik AY, Mutlu S, Ulgen KO Tags: Biomed Microdevices Source Type: research

22 factorial design-based biocompatible microneedle arrays containing artemether co-loaded with lumefantrine nanoparticles for transepidermal delivery.
Abstract The present study was intended to enhance the permeation of artemether and lumefantrine by encapsulating in dissolvable microneedle arrays for extended action. Lumefantrine-nanoparticles were synthesized using chitosan mediated gelation and optimized by 22 factorial designs. The particle size, zeta potential and % entrapment efficiency of the optimized nanoparticles F5 were 105 ± 3.64 nm, 24.4 ± 0.54 mV and 83.94 ± 1.71%, respectively. The nanoparticles showed a controlled-release of 79.15 ± 2.45% for lumefantrin...
Source: Biomedical Microdevices - February 19, 2020 Category: Biomedical Engineering Authors: Pawar S, Shende P Tags: Biomed Microdevices Source Type: research

Screen-printed electrochemical biosensor based on a ternary Co@MoS2/rGO functionalized electrode for high-performance non-enzymatic glucose sensing.
In this study, cobalt oxides functionalized MoS2/reduced graphene oxide was synthesized via a facile one-pot hydrothermal approach. Morphology and crystal structure of this ternary nanoarchitecture were characterized through scanning electron microscopy, transmission electron microscopy, Raman spectra and X-ray photoelectron spectroscopy. An ultrasensitive non-enzymatic glucose sensor was developed by decorating this ternary nanohybrid on the working electrode of a screen-printed electrochemical sensor. Cycle sweep voltammetry and amperometry were used to study the electro-catalytic activity of the modified working electro...
Source: Biomedical Microdevices - February 15, 2020 Category: Biomedical Engineering Authors: Li X, Zhang M, Hu Y, Xu J, Sun D, Hu T, Ni Z Tags: Biomed Microdevices Source Type: research

A centrifugal microfluidic emulsifier integrated with oil storage structures for robust digital LAMP.
Abstract Centrifugal droplet-based microfluidic devices have been applied to biomedical analysis and diagnostics recently. However, in centrifugal droplet-based microfluidic devices, droplets are tightly packed (i.e., the oil film between neighbouring droplets is thin). Therefore, droplet coalescence usually occurs especially during thermal incubation process. To preserve individual droplets in the devices, we report a new design for monodisperse droplet generation and storage that exploits a centrifugal configuration for droplet emulsification and oil-storage structures (OSSs) for regulation of the thickness of o...
Source: Biomedical Microdevices - February 15, 2020 Category: Biomedical Engineering Authors: Peng H, Zhu M, Gao Z, Liao C, Jia C, Wang H, Zhou H, Zhao J Tags: Biomed Microdevices Source Type: research

Research Progress of nucleic acid delivery vectors for gene therapy.
Abstract Gene therapy has broad prospects as an effective treatment for some cancers and hereditary diseases. However, DNA and siRNA are easily degraded in vivo because of their biological activities as macromolecules, and they need the effective transmembrane delivery carrier Selecting the appropriate carrier for delivery will allow nucleic acid molecules to reach their site of action and enhance delivery efficiency. Currently used nucleic acid delivery vectors can be divided into two major categories: viral and non-viral vectors. Viral carrier transport efficiency is high, but there are safety issues. Non-viral ...
Source: Biomedical Microdevices - January 27, 2020 Category: Biomedical Engineering Authors: Jiao Y, Xia ZL, Ze LJ, Jing H, Xin B, Fu S Tags: Biomed Microdevices Source Type: research

Analysis of the capacitance of minimally insulated parallel wires implanted in biological tissue.
Abstract State of the art bioelectronic implants are using thin cables for therapeutic electrical stimulation. If cable insulation is thin, biological tissue surrounding cables can be unintentionally stimulated. The capacitance of the cable must be much less than the stimulating electrodes to ensure stimulating currents are delivered to the electrode-tissue interface. This work derives and experimentally validates a model to determine the capacitance of parallel cables implanted in biological tissue. Biological tissue has a high relative permittivity, so the capacitance of cabling implanted in the human body depen...
Source: Biomedical Microdevices - January 21, 2020 Category: Biomedical Engineering Authors: Tsai RJ, Aldaoud A, Redoute JM, Garrett DJ, Prawer S, Grayden DB Tags: Biomed Microdevices Source Type: research

Enhancing droplet transition capabilities using sloped microfluidic channel geometry for stable droplet operation.
Abstract Droplet-based microfluidics technology allows for the generation and control of droplets that function as independent chemical and biological reactors, enabling broad ranges of high-throughput assays. As more complex multi-step assays are being realized in droplet format, maintaining droplet stability throughout the assay becomes a critical requirement. Unfortunately, as droplets go through multiple manipulation steps, droplet breakage is commonly seen, especially where droplets have to go through sharp transitions in direction and shape. Standard microfabrication techniques typically result in inherent s...
Source: Biomedical Microdevices - January 21, 2020 Category: Biomedical Engineering Authors: Wippold JA, Huang C, Stratis-Cullum D, Han A Tags: Biomed Microdevices Source Type: research

On-chip simultaneous rotation of large-scale cells by acoustically oscillating bubble array.
Abstract Bubbles locating in microfluidic chamber can produce acoustic streaming vortices by applying travelling surface acoustic wave oscillation in an ultrasonic range, which can be used to drive bio-samples to move within the flow field. In this paper, a strategy of bubble array configured in a large number of regularly arranged horseshoe structures is proposed to capture and rotate cells simultaneously. By modifying the geometric parameters of the horseshoe structure and microfluidic setting, high bubble homogeneity and cell trapping percentage was achieved. The simulation and experimental results of the bubbl...
Source: Biomedical Microdevices - January 18, 2020 Category: Biomedical Engineering Authors: Tang Q, Liang F, Huang L, Zhao P, Wang W Tags: Biomed Microdevices Source Type: research

Fabrication of separable microneedles with phase change coating for NIR-triggered transdermal delivery of metformin on diabetic rats.
Abstract To enhance the compliance of drug delivery for patients, the novel near-infrared (NIR) light-triggered and separable microneedles (MNs) have been developed in this work. Firstly, prussian blue nanoparticles (PB NPs) as the photo-thermal conversion factor and metformin as the hypoglycemic drug were embedded into the separable arrowheads, which consisted by poly (vinyl alcohol) and sucrose (PVA/Suc). The arrowheads of MNs were located on soluble solids supporting substrates that produced by poly(vinyl pyrrolidone) (PVP). Lauric acid (LA) as the phase transition coating covered on the surface of the MNs due ...
Source: Biomedical Microdevices - January 7, 2020 Category: Biomedical Engineering Authors: Liu T, Jiang G, Song G, Zhu J, Yang Y Tags: Biomed Microdevices Source Type: research

Development of a new and simple method for the detection of histidine-tagged proteins based on thionine-chitosan/gold nanoparticles/horseradish peroxidase.
Abstract In the current study, an electrochemical biosensing signal amplification system was utilized with thionine-chitosan-gold nanoparticles (Chit-GNPs) that absorbed horseradish peroxidase (HRP) and anti-His tagged protein monoclonal antibody derived from Balb/c mice. In addition, transmission electron microscopy (TEM) was used to characterize the nanogold solution and atomic force microscopy (AFM) was used to characterize the sensor assembly. To evaluate the quality of the immunosensor, the amperometric I-t curve method was applied to determine His-IL23 in PBS. The results indicated that the response current ...
Source: Biomedical Microdevices - January 2, 2020 Category: Biomedical Engineering Authors: Ren R, Lu D, Pang G Tags: Biomed Microdevices Source Type: research

Bioprinting a 3D vascular construct for engineering a vessel-on-a-chip.
In this study, we applied the gelatin-methacryloyl-based bioprinting technology to print 3D construct containing endothelial cells (ECs) and smooth muscle cells (SMCs) on a microfluidic chip. Compared with traditional culture system, EC-SMC coculturing chip model upregulated αSMA and SM22 protein expression of the SMC to a greater degree and maintains the contractile phenotype of the SMC, which mimics the natural vascular microenvironment. This strategy enabled us to establish an in vitro vascular model for studies of the physiologic and pathologic process in vascular wall. PMID: 31875940 [PubMed - in process] (...
Source: Biomedical Microdevices - December 26, 2019 Category: Biomedical Engineering Authors: Abudupataer M, Chen N, Yan S, Alam F, Shi Y, Wang L, Lai H, Li J, Zhu K, Wang C Tags: Biomed Microdevices Source Type: research

Microfluidic vascular-bed devices for vascularized 3D tissue engineering: tissue engineering on a chip.
In this report, we describe a microfluidic vascular-bed (micro-VB) device providing a platform for 3D tissue engineering with vascular network formation. The micro-VB device allows functional connections between endothelial capillaries of heterogeneous sections (5-100 μm in diameter) and artificial plastic tubes or reservoirs (1-10 mm in diameter). Moreover, the micro-VB device can be installed in a standard 100 mm-diameter Petri dish. Endothelial networks in 3D engineered tissues were obtained by cellular self-assembly on the device, after co-culturing of human umbilical vein endothelial cells (HUVECs) a...
Source: Biomedical Microdevices - December 20, 2019 Category: Biomedical Engineering Authors: Takehara H, Sakaguchi K, Sekine H, Okano T, Shimizu T Tags: Biomed Microdevices Source Type: research

Paper based point of care immunosensor for the impedimetric detection of cardiac troponin I biomarker.
Abstract Advancements in health care monitoring demand a rapid, accurate and reliable early diagnosis of "Heart Attack" (acute myocardial infarction) with an objective to develop a cost-effective, rapid and label-free point of care diagnostic test kit for the detection of cardiac troponin I (cTnI) on paper-based multi-frequency impedimetric transducers. Paper based sensing platforms were developed by integrating carboxyl group functionalized multi-walled carbon nanotubes (MWCNT) with antibodies of cardiac troponin I (anti-cTnI) biomarker and was characterized using Electrochemical Impedance Spectroscopy ...
Source: Biomedical Microdevices - December 16, 2019 Category: Biomedical Engineering Authors: Vasantham S, Alhans R, Singhal C, Nagabooshanam S, Nissar S, Basu T, Ray SC, Wadhwa S, Narang J, Mathur A Tags: Biomed Microdevices Source Type: research

Bio-inspired microneedle design for efficient drug/vaccine coating.
Abstract Biomimetics is the interdisciplinary scientific field focused on the study and imitation of biological systems, with the aim of solving complex technological problems. In this paper, we present a new bio-inspired design for microneedles (MNs) and MN arrays, intended for rapidly coating the MNs with drug/vaccine. The biomimetic approach consists in ornamenting the lateral sides of pyramidal MNs with structures inspired by the external scent efferent systems of some European true bugs, which facilitate a directional liquid transport. To realize these MNs, two-photon polymerization (TPP) technique was used. ...
Source: Biomedical Microdevices - December 16, 2019 Category: Biomedical Engineering Authors: Plamadeala C, Gosain SR, Hischen F, Buchroithner B, Puthukodan S, Jacak J, Bocchino A, Whelan D, O'Mahony C, Baumgartner W, Heitz J Tags: Biomed Microdevices Source Type: research

Coated microneedles for transdermal delivery of a potent pharmaceutical peptide.
The objective of this study was to develop a drug product using the MN technology that has similar bioperformance when compared to subcutaneous route of delivery and can provide improved stability under storage. Therapeutic peptide (Peptide A, Merck & Co., Inc., Kenilworth, NJ, USA) is being developed as a subcutaneous injection for chronic dosing with a submilligram estimated therapeutic dose. Peptide A has chemical and physical stability challenges in solution and this led to exploration of a viable drug product which could provide therapeutic dosages while overcoming the stability issues seen with the compound. This...
Source: Biomedical Microdevices - December 16, 2019 Category: Biomedical Engineering Authors: Kapoor Y, Milewski M, Dick L, Zhang J, Bothe JR, Gehrt M, Manser K, Nissley B, Petrescu I, Johnson P, Burton S, Moseman J, Hua V, Grunewald T, Tomai M, Smith R Tags: Biomed Microdevices Source Type: research

Design and fabrication of portable continuous flow PCR microfluidic chip for DNA replication.
Abstract The reasons for restricting continuous flow polymerase chain reaction (CF-PCR) microfluidic chip from lab to application are that it is not portable and requires costly external precision pumps for sample injection. Herein, we employed water as the substitute for PCR solution, and investigated the effect of the cross-section, width-to-depth ratio, and the length ratio for three temperature zones of the micro channel on the thermal and flow distribution of fluid in micro tube by finite element analysis. Results show that the central velocity is uniform and stable velocity occupies the most if the cross-sec...
Source: Biomedical Microdevices - December 10, 2019 Category: Biomedical Engineering Authors: Li Z, Li Y, Sekine S, Xi H, Amano A, Zhang D, Yamaguchi Y Tags: Biomed Microdevices Source Type: research

Development of rolled scaffold for high-density adherent cell culture.
Abstract Bioreactors for large-scale culture of mammalian cells are playing vital roles in biotechnology and bioengineering. Various bioreactors have been developed, but their capacity and efficiency are often limited by insufficient mass transfer rate and high shear stress. A rolled scaffold (RS) is a fully defined scaffold for high-density adherent culture of mammalian cells. The RS is a polymer film with spacers, that is rolled into a cylinder with a pre-determined gap between each turn. Cells are cultured on its inner surfaces, while media flows through the gap. The RS exhibits high surface-area-to-volume rati...
Source: Biomedical Microdevices - December 7, 2019 Category: Biomedical Engineering Authors: YekrangSafakar A, Hamel KM, Mehrnezhad A, Jung JP, Park K Tags: Biomed Microdevices Source Type: research

Estimation of pO2 histogram from a composite EPR Spectrum of multiple random implants.
Abstract Electron paramagnetic resonance (EPR) spectroscopy using oxygen-sensing implants can provide reliable and repeated measurements of the partial pressure of oxygen (pO2) over a period of months or longer; however, it does not provide accurate information about the distribution of tissue oxygenation. While EPR imaging has the capability to provide spatially resolved oxygen data, it is time-consuming and not optimized for discrete number of implants. Previous reports suggest multi-site algorithms, which would require either the implants to be aligned in a certain way so as to deconvolve them using a linear ma...
Source: Biomedical Microdevices - December 3, 2019 Category: Biomedical Engineering Authors: Kuppusamy P, Kmiec MM, Tse D, Mast JM, Ahmad R Tags: Biomed Microdevices Source Type: research

An overview on the exponential growth of non-invasive diagnosis of diabetes mellitus from exhaled breath by nanostructured metal oxide Chemi-resistive gas sensors and μ-preconcentrator.
An overview on the exponential growth of non-invasive diagnosis of diabetes mellitus from exhaled breath by nanostructured metal oxide Chemi-resistive gas sensors and μ-preconcentrator. Biomed Microdevices. 2019 Dec 03;22(1):2 Authors: Kalidoss R, Umapathy S Abstract The characterization of acetone in exhaled breath reflects the internal metabolism of glucose in bloodstream and airways. This phenomenon provides a great potential for non-invasive diagnosis of diabetes mellitus and has inspired medical sodalities as an alternative diagnostic tool. This review discusses about the origination of aceton...
Source: Biomedical Microdevices - December 3, 2019 Category: Biomedical Engineering Authors: Kalidoss R, Umapathy S Tags: Biomed Microdevices Source Type: research

One-step microchip for DNA fluorescent labeling.
In this study, we propose a microchip that is sequentially capable of fluorescently staining and washing DNAs. The main advantage of this microchip is that it allows for one-step preparation of small amounts of solution without degrading microscopic bio-objects such as the DNAs, cells, and biomolecules to be stained. The microchip consists of two inlets, the main channel, staining zone, washing zone, and one outlet, and was processed using a femtosecond laser system. High molecular transport of rhodamine B to deionized water was observed in the performance test of the microchip. Results revealed that the one-step procedure...
Source: Biomedical Microdevices - November 28, 2019 Category: Biomedical Engineering Authors: Jang Y, Shin H, Jung J, Oh J Tags: Biomed Microdevices Source Type: research