Subjects -> MEDICAL SCIENCES (Total: 8669 journals)
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MEDICAL SCIENCES (2406 journals)            First | 1 2 3 4 5 6 7 8 | Last

Showing 201 - 400 of 3562 Journals sorted alphabetically
Asian Biomedicine     Open Access   (Followers: 2)
Asian Journal of Cell Biology     Open Access   (Followers: 6)
Asian Journal of Health     Open Access   (Followers: 3)
Asian Journal of Medical and Biological Research     Open Access   (Followers: 5)
Asian Journal of Medical and Pharmaceutical Researches     Open Access   (Followers: 2)
Asian Journal of Medical Sciences     Open Access   (Followers: 2)
Asian Journal of Medicine and Health     Open Access   (Followers: 1)
Asian Journal of Research in Medical and Pharmaceutical Sciences     Open Access   (Followers: 1)
Asian Journal of Scientific Research     Open Access   (Followers: 3)
Asian Journal of Transfusion Science     Open Access   (Followers: 1)
Asian Medicine     Hybrid Journal   (Followers: 5)
Asian Pacific Journal of Cancer Prevention     Open Access  
Asian Pacific Journal of Health Sciences     Open Access   (Followers: 10)
ASPIRATOR : Journal of Vector-borne Disease Studies     Open Access  
Astrocyte     Open Access  
Atención Familiar     Open Access  
Atención Primaria     Open Access   (Followers: 2)
Atención Primaria Práctica     Open Access   (Followers: 1)
Atti della Accademia Peloritana dei Pericolanti - Classe di Scienze Medico-Biologiche     Open Access  
Audiology - Communication Research     Open Access   (Followers: 10)
AUP Advances     Open Access   (Followers: 8)
Auris Nasus Larynx     Full-text available via subscription  
Australasian Journal of Ultrasound in Medicine (AJUM)     Hybrid Journal   (Followers: 1)
Australian Coeliac     Full-text available via subscription   (Followers: 2)
Australian Family Physician     Full-text available via subscription   (Followers: 3)
Australian Journal of Medical Science     Full-text available via subscription   (Followers: 3)
Autopsy and Case Reports     Open Access  
Avicenna     Open Access   (Followers: 3)
Avicenna Journal of Clinical Medicine     Open Access  
Avicenna Journal of Medicine     Open Access   (Followers: 1)
Bangabandhu Sheikh Mujib Medical University Journal     Open Access   (Followers: 1)
Bangladesh Journal of Anatomy     Open Access   (Followers: 2)
Bangladesh Journal of Bioethics     Open Access  
Bangladesh Journal of Medical Biochemistry     Open Access   (Followers: 4)
Bangladesh Journal of Medical Education     Open Access   (Followers: 2)
Bangladesh Journal of Medical Microbiology     Open Access   (Followers: 4)
Bangladesh Journal of Medical Physics     Open Access   (Followers: 1)
Bangladesh Journal of Medical Science     Open Access  
Bangladesh Journal of Medicine     Open Access   (Followers: 1)
Bangladesh Journal of Physiology and Pharmacology     Open Access  
Bangladesh Journal of Scientific Research     Open Access   (Followers: 1)
Bangladesh Medical Journal     Open Access  
Bangladesh Medical Journal Khulna     Open Access  
Basal Ganglia     Hybrid Journal  
Basic Sciences of Medicine     Open Access   (Followers: 1)
Batı Karadeniz Tıp Dergisi / Medical Journal of Western Black Sea     Open Access  
Baylor University Medical Center Proceedings     Hybrid Journal  
BBA Clinical     Open Access  
BC Medical Journal     Free  
Benha Medical Journal     Open Access  
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (Followers: 3)
Bijblijven     Hybrid Journal  
Bijzijn     Hybrid Journal   (Followers: 1)
Bijzijn XL     Hybrid Journal  
Bio-Algorithms and Med-Systems     Hybrid Journal   (Followers: 2)
BioDiscovery     Open Access   (Followers: 2)
Bioelectromagnetics     Hybrid Journal   (Followers: 2)
Bioelectronic Medicine     Open Access   (Followers: 1)
Bioengineering & Translational Medicine     Open Access  
Bioethics     Hybrid Journal   (Followers: 19)
Bioethics Research Notes     Full-text available via subscription   (Followers: 15)
Biologics in Therapy     Open Access  
Biology of Sex Differences     Open Access   (Followers: 2)
Biomarker Research     Open Access   (Followers: 3)
Biomarkers in Medicine     Hybrid Journal   (Followers: 2)
BioMed Research International     Open Access   (Followers: 5)
Biomédica     Open Access  
Biomedical & Life Sciences Collection     Full-text available via subscription   (Followers: 3)
Biomedical and Biotechnology Research Journal     Open Access   (Followers: 1)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 6)
Biomedical Engineering Research     Open Access   (Followers: 7)
Biomedical Informatics Insights     Open Access   (Followers: 9)
Biomedical Journal     Open Access   (Followers: 4)
Biomedical Materials     Hybrid Journal   (Followers: 7)
Biomedical Microdevices     Hybrid Journal   (Followers: 9)
Biomedical Optics Express     Open Access   (Followers: 6)
Biomedical Photonics     Open Access  
Biomedical Reports     Full-text available via subscription  
Biomedical Research Reports     Full-text available via subscription   (Followers: 2)
Biomedical Safety & Standards     Full-text available via subscription   (Followers: 9)
Biomedical Science and Engineering     Open Access   (Followers: 7)
BioMedicine     Open Access  
Biomedicine Hub     Open Access  
Biomedicines     Open Access   (Followers: 1)
Biomedika     Open Access  
Biomolecular and Health Science Journal     Open Access   (Followers: 1)
Biophysics Reports     Open Access  
BioPsychoSocial Medicine     Open Access   (Followers: 8)
Biosafety and Health     Open Access   (Followers: 2)
Biosalud     Open Access   (Followers: 1)
Biostatistics & Epidemiology     Hybrid Journal   (Followers: 2)
Birat Journal of Health Sciences     Open Access  
BIRDEM Medical Journal     Open Access   (Followers: 1)
Birth Defects Research     Hybrid Journal  
Birth Defects Research Part A : Clinical and Molecular Teratology     Hybrid Journal   (Followers: 3)
Birth Defects Research Part C : Embryo Today : Reviews     Hybrid Journal  
BJR|Open     Open Access   (Followers: 1)
BJS Open     Open Access   (Followers: 1)
Black Sea Journal of Health Science     Open Access  
BLDE University Journal of Health Sciences     Open Access  
Blickpunkt Medizin     Hybrid Journal  
BMC Biomedical Engineering     Open Access  
BMC Medical Ethics     Open Access   (Followers: 22)
BMC Medical Research Methodology     Open Access   (Followers: 9)
BMC Medicine     Open Access   (Followers: 14)
BMC Obesity     Open Access   (Followers: 7)
BMC Proceedings     Full-text available via subscription   (Followers: 2)
BMC Research Notes     Open Access   (Followers: 4)
BMC Sports Science, Medicine and Rehabilitation     Open Access   (Followers: 34)
BMH Medical Journal     Open Access   (Followers: 2)
BMI Journal : Bariátrica & Metabólica Iberoamericana     Open Access  
BMJ     Hybrid Journal   (Followers: 1885)
BMJ Case Reports     Hybrid Journal   (Followers: 28)
BMJ Evidence-Based Medicine     Hybrid Journal   (Followers: 4)
BMJ Global Health     Open Access   (Followers: 3)
BMJ Innovations     Hybrid Journal   (Followers: 6)
BMJ Leader     Hybrid Journal  
BMJ Open     Open Access   (Followers: 44)
BMJ Open Quality     Open Access   (Followers: 19)
BMJ Open Science     Open Access   (Followers: 1)
BMJ Sexual & Reproductive Health     Hybrid Journal   (Followers: 2)
BMJ Surgery, Interventions, & Health Technologies     Open Access  
Bodine Journal     Open Access  
Boletín del Consejo Académico de Ética en Medicina     Open Access  
Boletín del ECEMC     Open Access  
Boletin Médico de Postgrado     Open Access  
Boletín Médico del Hospital Infantil de México     Open Access  
Bone     Hybrid Journal   (Followers: 18)
Bone and Tissue Regeneration Insights     Open Access   (Followers: 2)
Bone Marrow Research     Open Access   (Followers: 2)
Bone Reports     Open Access  
Bosnian Journal of Basic Medical Sciences     Open Access  
Bozok Tıp Dergisi / Bozok Medical Journal     Open Access  
Brachytherapy     Full-text available via subscription   (Followers: 6)
Brain and Development     Full-text available via subscription   (Followers: 5)
Brain Communications     Open Access   (Followers: 3)
Brain Connectivity     Hybrid Journal   (Followers: 5)
Brain Impairment     Full-text available via subscription   (Followers: 2)
Brazilian Journal of Medical and Biological Research     Open Access  
Brazilian Journal of Medicine and Human Health     Open Access  
Brazilian Journal of Pain (BrJP)     Open Access  
Brazilian Journal of Physical Therapy     Open Access   (Followers: 2)
Breastfeeding Review     Full-text available via subscription   (Followers: 19)
British Journal of Biomedical Science     Full-text available via subscription   (Followers: 7)
British Journal of General Practice     Full-text available via subscription   (Followers: 39)
British Journal of Hospital Medicine     Full-text available via subscription   (Followers: 16)
British Medical Bulletin     Hybrid Journal   (Followers: 6)
Buddhachinaraj Medical Journal     Open Access  
Bulletin Amades     Open Access  
Bulletin de la Société de pathologie exotique     Hybrid Journal   (Followers: 1)
Bulletin of Legal Medicine     Open Access  
Bulletin of Medical Sciences     Open Access  
Bulletin of the History of Medicine     Full-text available via subscription   (Followers: 21)
Bulletin of the Menninger Clinic     Full-text available via subscription  
Bulletin of The Royal College of Surgeons of England     Free  
Bulletin of the Scientific Centre for Expert Evaluation of Medicinal Products     Open Access  
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz     Hybrid Journal   (Followers: 6)
Burapha Journal of Medicine     Open Access  
Burns     Hybrid Journal   (Followers: 10)
Cadernos de Naturologia e Terapias Complementares     Open Access   (Followers: 1)
Calcified Tissue International     Hybrid Journal   (Followers: 2)
Canadian Bulletin of Medical History     Hybrid Journal  
Canadian Family Physician     Partially Free   (Followers: 13)
Canadian Journal of Pain     Open Access   (Followers: 2)
Canadian Journal of Rural Medicine     Full-text available via subscription   (Followers: 1)
Canadian Medical Association Journal     Open Access   (Followers: 18)
Canadian Medical Education Journal     Open Access   (Followers: 10)
Canadian Prosthetics & Orthotics Journal     Open Access  
Cannabis and Cannabinoid Research     Hybrid Journal   (Followers: 1)
Cardiac Electrophysiology Clinics     Full-text available via subscription   (Followers: 1)
Care Management Journals     Hybrid Journal   (Followers: 5)
Case Reports     Open Access  
Case Reports in Acute Medicine     Open Access   (Followers: 2)
Case Reports in Clinical Medicine     Open Access   (Followers: 2)
Case Reports in Clinical Nutrition     Open Access   (Followers: 1)
Case Reports in Clinical Pathology     Open Access   (Followers: 1)
Case Reports in Medicine     Open Access   (Followers: 3)
Case Reports in Transplantation     Open Access  
Case Reports in Vascular Medicine     Open Access  
Case Reports in Women's Health     Open Access   (Followers: 4)
Case Study and Case Report     Open Access   (Followers: 5)
CASUS : Revista de Investigación y Casos en Salud     Open Access   (Followers: 1)
CBU International Conference Proceedings     Open Access   (Followers: 3)
Cell & Bioscience     Open Access   (Followers: 6)
Cell Adhesion & Migration     Open Access   (Followers: 9)
Cell and Molecular Response to Stress     Full-text available via subscription   (Followers: 2)
Cell and Tissue Transplantation and Therapy     Open Access   (Followers: 2)
Cell Cycle     Full-text available via subscription   (Followers: 6)
Cell Death and Differentiation     Hybrid Journal   (Followers: 8)
Cell Death Discovery     Open Access   (Followers: 1)
Cell Health and Cytoskeleton     Open Access   (Followers: 1)
Cell Medicine     Open Access   (Followers: 6)
Cell Research     Hybrid Journal   (Followers: 8)
Cell Transplantation     Open Access   (Followers: 4)
CEN Case Reports     Hybrid Journal  
Central African Journal of Medicine     Full-text available via subscription  
Cephalalgia Reports     Open Access   (Followers: 2)
Ceylon Journal of Medical Science     Open Access  

  First | 1 2 3 4 5 6 7 8 | Last

Similar Journals
Journal Cover
Biomedical Microdevices
Journal Prestige (SJR): 0.538
Citation Impact (citeScore): 2
Number of Followers: 9  
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1572-8781 - ISSN (Online) 1387-2176
Published by Springer-Verlag Homepage  [2626 journals]
  • Vitreous protein binding with nanopore dialysis membrane device
    • Abstract: Age-related macular degeneration (AMD) is one of the leading causes of blindness in the industrialized world, affecting over 8 million patients in the United State alone. While the wet (exudative) form of the disease is treated with intraocular injections, there are currently no approved therapies available for the dry (non-exudative) form of the disease which often affects both eyes in patients with AMD. Current research has focused on developing drugs that can be injected into the eye, but the treatment burden associated with monthly injections limits the effectiveness of this approach. Hence, there is a pressing need for a long-term therapeutic solution for patients suffering from this blinding disease. We detail a novel implantable intraocular device, which adsorbs and traps complement factors associated with AMD. 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.
      PubDate: 2020-07-04
  • 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-1/Al2O3 nanoprobes (Galectin-1 antibody conjugated to alumina nanoparticles) that can be selectively trapped on the microelectrode surface using positive dielectrophoresis (p-DEP). Preliminary studies highlight the feasibility of the proposed immunosensor for Gal −1 detection in T24 cell lysate spiked phosphate buffer saline and artificial urine samples with a limit of detection that is estimated to be in the pg/ml range. To verify its practical feasibility, we have tested the immunosensor for Galectin-1 detection in clinical urine samples obtained from normal patients and those diagnosed with bladder cancer. Analysis of the clinical tests shows that the median normalized impedance variation during immunosensing for 22 cancer patients and 26 normal patients is 27% and 10%, respectively, with an identified cutoff point of 19.5% above which the sensitivity and specificity of bladder cancer detection was 82.1% and 80.8%, respectively. Based on these results, the proposed immunosensor shows promise for bladder cancer diagnosis and prognosis in a point of care format, thus enabling improved public health monitoring.
      PubDate: 2020-06-30
  • Poly-L-histidine coated microfluidic devices for bacterial DNA
           purification without chaotropic solutions
    • Abstract: 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 than their pKa of surface amine-groups which is 6.0 and then released at a pH higher than the pKa value (10.5). It was found that modification with poly-L-histidine resulted in higher surface density of amine groups onto microfluidic channel. Using the chip modified with poly-L-histidine, high recovery efficiency of at least 550 ng of isolated Salmonella DNA as well as DNA purification from Salmonella cell lysates corresponding to less than 5000 cells or 0.026 ng of Salmonella DNA was achieved. The protocol developed does not require ethanol or chaotropic solutions typically used in DNA purification, which are known inhibitors for downstream operations such as polymerase chain reactions (PCR) and which can also attack some polymeric microfluidic materials. Therefore, the microfluidic device and the related protocol hold promise for facile incorporation in microfluidics and Lab-on-a-chip (LOC) platforms for pathogen detection or in general for DNA purification.
      PubDate: 2020-06-22
  • Penetrating glassy carbon neural electrode arrays for brain-machine
    • 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 electrodes are packed with conductive wires and PDMS. The proposed fabrication method simplifies the manufacturing process of carbon materials, and electrodes can be fabricated without the need of deep reactive ion etching (DRIE). The height of the carbon electrodes is 1.5 mm, and the exposure area of the tips is 0.78 mm2, which is convenient for the implantation procedure. The specific capacitance of the glassy carbon arrays is higher than that of a platinum electrode (9.18 mF/cm2 vs 3.32 mF/cm2, respectively), and the impedance at 1 kHz is lower (7.1 kΩ vs 8.8 kΩ). The carbon electrodes were tested in vivo, and they showed excellent performance in neural signal recording. The signal-to-noise ratio of the carbon electrodes is 50.73 ± 6.11, which is higher than that of the Pt electrode (20.15 ± 5.32) under the same testing conditions. The proposed fabrication method of glassy carbon electrodes provides a novel approach to manufacture penetrating electrodes for nerve interfaces in biomedical engineering and microelectromechanical systems.
      PubDate: 2020-06-06
  • 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 due to their mitigation of vortex effects and preservation of flow symmetry under high Re conditions. While high-Re operation with symmetric airfoil shaped pillars has been established, the effect of AoAs on the DLD performance has not been investigated. In this paper, we have characterized the airfoil DLD device with various AoAs. The transport behavior of microparticles has been observed and analyzed with various AoAs in realistic high-Re. Furthermore, we have modeled the flow fields and anisotropy in a representative airfoil pillar array, for both positive and negative AoA configurations. Unlike the conventional DLD device, lateral displacement has been suppressed with +5° and + 15° AoA configurations regardless of particle sizes. On the other hand, stronger lateral displacement has been seen with −5° and − 15° AoAs. This can be attributed to growing flow anisotropy as Re climbs, and significant expansion or compression of streamlines between airfoils with AoAs. The findings in this study can be utilized for the design and optimization of airfoil DLD microfluidic devices with various AoAs.
      PubDate: 2020-06-03
  • Covalent immobilization of luminescent oxygen indicators reduces
    • 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 indicators are covalently immobilized into a polymer matrix consisting of polystyrene and poly(pentafluorostyrene). We study how the covalent immobilization influences the sensing material’s cytotoxicity to human induced pluripotent stem cell-derived (hiPSC-derived) neurons and cardiomyocytes (CMs) through 7–13 days culturing experiments and various viability analyses. Furthermore, we study the effect of the covalent immobilization on the indicator leaching and the oxygen sensing properties of the material. In addition, we demonstrate the use of the covalently linked oxygen sensing material in real time oxygen tension monitoring in functional hypoxia studies of the hiPSC-derived CMs. The results show that the covalently immobilized indicators substantially reduce indicator leaching and the cytotoxicity of the oxygen sensing material, while the influence on the oxygen sensing properties remains small or nonexistent.
      PubDate: 2020-06-03
  • High-throughput cell migration assay under combinatorial chemical
           environments by a novel 24-well-plate based device
    • Abstract: The quantitative studies of cell proliferation and migration under different chemical environments are important for both scientists and clinicians searching for new therapeutics. 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 behaviors of four types of cells under 24 types of EGF + bFGF combinatorial conditions were studied. We believed this device could be widely used in clinical searching for new anti-cancer therapeutics and other related studies.
      PubDate: 2020-05-30
  • 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 which simplifies HIV testing. An indicator is incorporated into the cassette to guide sample introduction based on color change, and further, the excess test sample is stored inside the sealed cassette to avoid any contamination. The low-cost handheld optical reader can provide a test result within a few seconds, which is useful for simple, sensitive and affordable HIV onsite detection. Instead of using normal white LEDs, a customized back light module embedded with green LEDs is adopted to illuminate the lateral flow strip with an appropriate working current to achieve optimal performance. Compared to the standard lateral flow strips using a benchtop reader, with the disposable immunoassay cassette assisted by the handheld optical reader, more convenient, easier-to-operate, and more affordable HIV urine testing can be achieved in POC diagnostics.
      PubDate: 2020-05-21
  • 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 time. The online real time sample analyzes have also been performed by the device connected with an embedded electronic circuit interfaced with a laptop through appropriate software. This has enabled the development of a novel Si-chip based compact point-of-care (POC) diagnosis system for Hct level estimation by measuring the dielectric/capacitive variation of an erythrocyte cell suspension. The relevant performance parameters of such a compact system including range, resolution, limit of detection and throughput have also been evaluated.
      PubDate: 2020-05-20
  • 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 rigid microfabricated shadow mask, used for filling drugs in microcontainers, the PDMS masking technique allows more facile and precise loading of higher quantities of an active compound, without the need of alignment. The method provides flexibility and is adjustable to devices fabricated from different materials with various geometries, topologies and dimensions. This user-friendly flexible masking method overcomes the limitations of other masking techniques and is certainly not limited to ODD and is recommended for a wide range of microdevices.
      PubDate: 2020-05-18
  • 3D-Printed micro-optofluidic device for chemical fluids and cells
    • 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 solution allows to realize a PDMS micro-device taking the advantage of 3D- Printing and goes beyond the restriction in the material selection. The device’s performances were tested in the fluids detection and in the evaluation of the cell concentrations. Additionally, the micro-device was used as a real-time two-phase fluids flow detector. The two-phases flows were successfully monitored in different experimental conditions, varying both hydrodynamic and optical external stimuli.
      PubDate: 2020-05-18
  • 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 provides information for multiple biomarkers can aid in the diagnosis and prognosis of potentially septic patients. Using impedance cytometry, microbead immunoassays, and biotin-streptavidin binding, we report a microfluidic POC system that correlates microbead capture to IL-6 and PCT concentrations. A multiplexed microbead immunoassay is developed and validated for simultaneous detection of both IL-6 and PCT from human plasma samples. Using the POC platform, we quantified plasma samples containing healthy, medium (~103pg/ml) and high (~105pg/ml) IL-6 and PCT concentrations with various levels of significance (P < 0.05-P < 0.00001) and validated the concept of this device as a POC platform for sepsis biomarkers.
      PubDate: 2020-05-18
  • Biomimetic aorta-gonad-Mesonephros-on-a-Chip to study human developmental
    • 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 pluripotent stem cells (hiPSCs) were cultured on a layer of mesenchymal stromal cells in the top channel while vascular endothelial cells were co-cultured on the bottom side of the membrane within the microfluidic device. We show that this AGM-on-a-chip efficiently derives endothelial-to-hematopoietic transition (EHT) from hiPSCs compared with regular suspension culture. The presence of mesenchymal stroma and endothelial cells renders functional HPCs in vitro. We propose that the AGM-on-a-chip could serve as a platform to dissect the cellular and molecular mechanisms of human developmental hematopoiesis.
      PubDate: 2020-05-06
  • Optical measurement platform of temperature-dependent interaction between
           nanoliposomes and a polymer-grafted surface
    • Abstract: 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-dependent detachment behavior of DLPC nanoliposomes, which was because of the phase transition of DLPC, was observed. The opto-microfluidic platform for individual nanoparticle measurements may become a powerful tool for investigating temperature-dependent physicochemical properties of nanoparticles in aqueous solution.
      PubDate: 2020-05-04
  • Rapid lipid bilayer membrane formation on Parylene coated apertures to
           perform ion channel analyses
    • Abstract: 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 hydrophobic and biocompatible Parylene layer. We tested both Parylene-C and Parylene-AF4. The contact angle measurements on both Parylene types showed very good hydrophobic properties and affinity to lipids. No precoating of the Parylene with an organic solvent is needed to make the aperture lipophilic, in contradiction to Teflon membranes. The chips can be easily placed in an array utilizing a 3D printed platform. Experiments show repetitive LBL formation and destruction (more than 6 times) within a very short time (few seconds). Through measurements we have established that the LBL layers are very thin. This allows the investigation of the fusion process of membrane proteins i.e. outer membrane protein (OmpF) in the LBL within a few minutes.
      PubDate: 2020-04-30
  • Breast Tumor Targeting with PAMAM-PEG-5FU- 99m Tc 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 analysis (16.97%). Drug release profiles of PEG-PAMAM G4-FA-5FU-99mTc and PEG-PAMAM G4-FA-5FU were evaluated. The radiochemical purity of PEG-PAMAM G4-FA-5FU-99mTc and PEG-PAMAM G4-FA-99mTc was obtained at >95% with excellent in-vitro and in-vivo stabilities. PEG-PAMAM G4-FA-5FU-99mTc was synthesized and the stability studies were carried out by the ITLC methods in serum (86.67% and 83.75%) and PBS. Combinational therapy effects of 5-FU and 99mTc containing nano-complexes were evaluated on 4 T1 (mouse breast cancer) and MDA-MB-231 (human breast adenocarcinoma) cancer cell lines. Excellent uptake values were obtained for FA-decorated nano-complexes on 4 T1 and MDA-MB-231 cell lines. Subsequently, tumor inhibition effects of PEG-PAMAM G4-FA-5FU-99mTc and PEG-PAMAM G4-FA-5FU were evaluated using the breast tumor-bearing BALB/C mice. Graphical abstract Breast Tumor Targeting with PAMAM-PEG-5FU- 99mTc As a New Therapeutic Nanocomplex: in In-vitro and In-vivo Studies was presented. This targeted drug delivery system can significantly increase the efficiency of cancer therapy, and reduce the treatment cost and time.
      PubDate: 2020-04-25
  • Interdigitated aluminium and titanium sensors for assessing epithelial
           barrier functionality by electric cell-substrate impedance spectroscopy
    • 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 properties of two adherent epithelial barrier tissue models: renal proximal tubular LLC-PK1 cells, representing a normal functional transporting epithelium, and human cervical cancer-derived HeLa cells, forming non-transporting cancerous epithelial tissue. Then, the impedance spectra obtained were analysed by numerically fitting the parameters of the two different models to the measured impedance spectrum. Aluminium sensors proved to be as sensitive and consistent in repeated online-recordings for continuous cell growth and differentiation monitoring as sensors made of gold, the standard electrode material. Titanium electrodes exhibited an elevated intrinsic ohmic resistance in comparison to gold reflecting its lower electric conductivity. Analysis of impedance spectra through applying models and numerical data fitting enabled the detailed investigation of the development and properties of a functional transporting epithelial tissue using either gold or aluminium sensors. The result of the data obtained, supports the consideration of aluminium and titanium sensor materials as potential alternatives to gold sensors for advanced application of ECIS spectroscopy.
      PubDate: 2020-04-24
  • 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-poor locations. Among the emerging clinical laboratory approaches, microfluidic technology has gained increasing attention over the last two decades due to the possibility of miniaturizing bioanalytical assays and instrumentation, thus potentially improving diagnostic performance. In this article, we review current developments related to the detection of CKD biomarkers using microfluidics. A general trend in this emerging area is the search for novel, sensitive biomarkers for early detection of CKD using technology that is improved by means of microfluidics. It is anticipated that these innovative approaches will be soon adopted and utilized in both clinical and point-of-care settings, leading to improvements in life quality of patients.
      PubDate: 2020-04-22
  • 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 flow channel to realize the modification. Finite element model simulation is performed for parametrical analysis and simplifying experiment design. 3 μm polystyrene fluorescent particles are adopted to test focusing effect. One dimension acoustic focusing is achieved at 2.95 MHz with single focusing node as well as 2, 3, 4 nodes focusing near 6, 9, 12 MHz respectively. The 2D focusing particle stream width in two dimensions is less than 10 μm. Results verified that this method is applicable for Jurkat cells. Sample flow maintains its stability without clogging up even at high sample concentration. Focusing still works at flow velocity over 100 μl/min. All these results certify this acoustic particles focusing method can enhance the performance of hydrodynamic flow cytometer by minor modification.
      PubDate: 2020-03-28
  • 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 captured antibody and sensitivity of the assay. Prominently, our developed CRP test kit is highly sensitive and rapid point of care test (POCT) which is capable to detect CRP with minimal volume (50–60 μl) and time (1–2 min) with diminutive detection up to 10 ng/ml. The reliability of our kit was evaluated and validated with spiked and clinical whole blood samples. The results demonstrated that our developed vertical flow-based point-of-care Immunokit may serve fruitful and semi-quantitative routine diagnostic for the early detection of cardiac disease.
      PubDate: 2020-03-28
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Tel: +00 44 (0)131 4513762

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