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Biomedical Microdevices

Yuxiang Pan, Xinwei Wei, Tao Liang, Jie Zhou, Hao Wan, Ning Hu, Ping Wang
Okadaic acid (OA), a representative diarrhetic shellfish poisoning toxin, mainly produced by toxigenic dinoflagellates, has significant hazard to public health. Traditional methods for detection of OA can not give the consideration to the need of rapid, high sensitive, quantitative and in-situ detection at the same time. Herein, a new effective detection method of OA was developed based on fluorescence immunosensor and flow cytometry (FCM). In this assay, Streptavidin-coated magnetic beads (MBs) were used as the supporter to immobilize the biotinylated OA...
July 13, 2018: Biomedical Microdevices
Daniel F Costa, Vladimir P Torchilin
Gene therapy has emerged as an alternative in the treatment of cancer, particularly in cases of resistance to chemo and radiotherapy. Different approaches to deliver genetic material to tumor tissues have been proposed, including the use of small non-coding RNAs due to their multiple mechanisms of action. However, such promise has shown limits in in vivo application related to RNA's biological instability and stimulation of immunity, urging the development of systems able to overcome those barriers. In this review, we discuss the use of RNA interference in cancer therapy with special attention to the role of siRNA and miRNA and to the challenges of their delivery in vivo...
July 12, 2018: Biomedical Microdevices
Takeshi Hatsuzawa, Mikiya Kurosaka
A cell culture device equipped with a micro-needle electrode array was fabricated for the signal analysis of cell spheroids, cell masses, and cell sheets. For the analysis, sharp needle electrodes with a high aspect ratio for facilitating easy penetration into the cell mass and a small pitch for fine spatial resolution were required. Microelectromechanical systems (MEMS) technology is one of the common solutions for the fabrication of devices. However, an additional process, such as anisotropic etching or electro-polishing, is required for fabricating sharp needles...
July 12, 2018: Biomedical Microdevices
Irem Ezgi Odabasi, Elif Gencturk, Sevde Puza, Senol Mutlu, Kutlu O Ulgen
Inhibition of DNA damage response pathway in combination with DNA alkylating agents may enhance the selective killing of cancer cells leading to better therapeutic effects. MDM2 binding protein (MTBP) in human has a role in G1 phase (interphase of cell cycle) and its overexpression leads to breast and ovarian cancers. Sld7 is an uncharacterized protein in budding yeast and a potential functional homologue of MTBP. To investigate the role of Sld7 as a therapeutic target, the behavior of the wild-type cells and sld7∆ mutants were monitored in 0...
July 5, 2018: Biomedical Microdevices
C Pease, G E Plum, B Kankia, J J Kwiek, R Sooryakumar
Nucleic acid testing is a common technique for medical diagnostics. For example, it is used to detect HIV treatment failure by monitoring viral load levels. Quadruplex Priming Amplification (QPA) is an isothermal nucleic acid amplification technique that requires little power and few chemical reagents per assay, all features that make QPA well suited for point-of-care (POC) diagnostics. The QPA assay can be further optimized by integrating it with microfluidic devices that can automate and combine multiple reaction steps and reduce the quantity and cost of reagents per test...
July 4, 2018: Biomedical Microdevices
Levy I Amar, Daniela Guisado, Monica Faria, James P Jones, Cees J M van Rijn, Michael I Hill, Edward F Leonard
Crossflow microfiltration of plasma from blood through microsieves in a microchannel is potentially useful in many biomedical applications, including clinically as a wearable water removal device under development by the authors. We report experiments that correlate filtration rates, transmembrane pressures (TMP) and shear rates during filtration through a microscopically high channel bounded by a low intrinsic resistance photolithographically-produced porous semiconductor membrane. These experiments allowed observation of erythrocyte behavior at the filtering surface and showed how their unique deformability properties dominated filtration resistance...
July 3, 2018: Biomedical Microdevices
Mi Jang, Andreas Manz, Thomas Volk, Astrid Kleber
Hepatocytes exhibit diverse reactions upon stimulation with the interleukin IL-6, mainly in the context of inflammation and energy metabolism. Melatonin has been shown to exert pleiotropic protective actions, such as anti-inflammation and anti-oxidative stress on many cell- and organ-types. The key role of the liver to maintain homeostasis and metabolic regulation prompted us to evaluate the direct modification of IL-6-induced alterations in HepG2 cells in a chip by melatonin. IL-6 administration was followed by the reduced expression and activity of MRP2, a loss of CYP1A activity, and the decline of PXR expression...
June 26, 2018: Biomedical Microdevices
Babita Sarangi, Utpal Jana, Jyotirmaya Sahoo, Guru Prasad Mohanta, Prabal Kumar Manna
Atorvastatin is a lipid lowering agent with poor oral bioavailability (12%) because of poor solubility and extensive first pass hepatic metabolism. In order to overcome these issues, atorvastatin loaded solid lipid nanoparticles (ATOR-SLNs) were prepared by using glyceryl tripalmitate as lipid carrier, poloxamer 407 as surfactant and soya lecithin as emulsifier. The purpose of this work was to optimize the formulation with the application of response surface methodology to improve the physicochemical properties...
June 26, 2018: Biomedical Microdevices
Kevin H Lam, Antonio Fernandez-Perez, David W Schmidtke, Nikhil V Munshi
Efficient intracellular cargo delivery is a key hurdle for the translation of many emerging stem cell and cellular reprogramming therapies. Recently, a microfluidic-based device constructed from silicon was shown to transduce macromolecules into cells via shear-induced formation of plasma membrane pores. However, the scalability and widespread application of the current platform is limited since physical deformation-mediated delivery must be optimized for each therapeutic application. Therefore, we sought to create a low-cost, versatile device that could facilitate rapid prototyping and application-specific optimization in most academic research labs...
June 25, 2018: Biomedical Microdevices
Xin Jin, Rui Chen, Shikun Zhao, Peiyong Li, Bai Xue, Xiang Chen, Xinyuan Zhu
In this article, an attempt for efficient screening of circulating tumor cells (CTCs) with excellent operability on microfluidic chips was reported. A Parsortix™-like cell separation chip was manufactured in our lab. This chip allowed lateral flow of fluid which increased the flow rate of blood. And, an air valve controlled injection pump was manufactured which allowed eight chips working simultaneously. This greatly facilitated the blood treatment process and saved time. As for the mechanism of screening circulating tumor cells, selective size amplification was utilized...
June 20, 2018: Biomedical Microdevices
Yu Song, Shuxiang Guo, Xuanchun Yin, Linshuai Zhang, Hideyuki Hirata, Hidenori Ishihara, Takashi Tamiya
In this paper, a novel robot-assisted catheter operating system (RCOS) has been proposed as a method to reduce physical stress and X-ray exposure time to physicians during endovascular procedures. The unique design of this system allows the physician to apply conventional bedside catheterization skills (advance, retreat and rotate) to an input catheter, which is placed at the master side to control another patient catheter placed at the slave side. For this purpose, a magnetorheological (MR) fluids-based master haptic interface has been developed to measure the axial and radial motions of an input catheter, as well as to provide the haptic feedback to the physician during the operation...
June 20, 2018: Biomedical Microdevices
Carly S Filgueira, Giacomo Bruno, Zachary W Smith, Corrine Ying Xuan Chua, Andrea Ballerini, Marco Folci, April L Gilbert, Priya Jain, Jagannadha K Sastry, Pramod N Nehete, Kathryn A Shelton, Lori R Hill, Areeba Ali, Keith A Youker, Alessandro Grattoni
With nearly 40% of U.S. adults obese, and childhood and adolescent rates rising, obesity and associated comorbidities are serious public health concerns with massive societal costs. Often, lifestyle interventions do not offer sufficient weight loss to improve health, requiring surgery and medications as adjunct management strategies. Here, we present a 4-month case study in which the sustained, low-dose, and constant administration of the thyroid receptor β selective agonist GC-1 (sobetirome) from a novel nanochannel membrane implant was assessed in an obese, pre-diabetic rhesus macaque...
June 18, 2018: Biomedical Microdevices
Audrey Hammack, Rashed T Rihani, Bryan J Black, Joseph J Pancrazio, Bruce E Gnade
Substrate-integrated microelectrode arrays (MEAs) are non-invasive platforms for recording supra-threshold signals, i.e. action potentials or spikes, from a variety of cultured electrically active cells, and are useful for pharmacological and toxicological studies. However, the MEA substrate, which is often fabricated using semiconductor processing technology, presents some challenges to the user. Specifically, the electrode encapsulation, which may consist of a variety of inorganic and organic materials, requires a specific substrate preparation protocol to optimize cell adhesion to the surface...
June 16, 2018: Biomedical Microdevices
Aykut Aksit, Daniel N Arteaga, Miguel Arriaga, Xun Wang, Hirobumi Watanabe, Karen E Kasza, Anil K Lalwani, Jeffrey W Kysar
The cochlea, or inner ear, is a space fully enclosed within the temporal bone of the skull, except for two membrane-covered portals connecting it to the middle ear space. One of these portals is the round window, which is covered by the Round Window Membrane (RWM). A longstanding clinical goal is to reliably and precisely deliver therapeutics into the cochlea to treat a plethora of auditory and vestibular disorders. Standard of care for several difficult-to-treat diseases calls for injection of a therapeutic substance through the tympanic membrane into the middle ear space, after which a portion of the substance diffuses across the RWM into the cochlea...
June 8, 2018: Biomedical Microdevices
Dingqiang Lu, Qiuda Xu, Guangchang Pang, Fuping Lu
An electrochemical double-layer Au nanoparticle membrane immunosensor was developed using an electrochemical biosensing signal amplification system with Au nanoparticles, thionine, chitosan, and horseradish peroxidase, which was fabricated using double self-adsorption of Au nanoparticle sol followed by anti-α-fetoprotein Balb/c mouse monoclonal antibody adsorption. The AuNPs sol was characterized by spectrum scanning and transmission electron microscopy. The immunosensor was characterized by atomic force microscopy, cyclic voltammetry, and alternating-current impedance during each stage of adsorption and assembly...
June 5, 2018: Biomedical Microdevices
Anurup Ganguli, Yoshihiko Watanabe, Michael T Hwang, Jui-Cheng Huang, Rashid Bashir
Detection of nucleic acid molecules is one of the most pervasive assays in biology, medicine, and agriculture applications. Currently, most comely used DNA/RNA detection platforms use fluorescence labeling and require lab-scale setting for performing the assay. There is a need for developing less expensive, label-free, and rapid detection of biomolecules with minimal utilization of resources. Use of electrical approaches for detection of biomolecules by utilizing their inherent charge is a promising direction for biosensing assays...
June 2, 2018: Biomedical Microdevices
Francesco Dal Dosso, Tadej Kokalj, Jaroslav Belotserkovsky, Dragana Spasic, Jeroen Lammertyn
In this work, we present a new iSIMPLE concept (infusion Self-powered Imbibing Microfluidic Pump by Liquid Encapsulation), which requires no external power for activation nor liquid manipulation, it is easy to use while its fabrication method is extremely simple, inexpensive and suited for mass replication. The pump consists of a working liquid, which is - after finger activation - absorbed in a porous material (e.g. filter paper). The air expelled from the porous material increases the pressure in the downstream outlet channel and propels the outlet liquid (i...
May 31, 2018: Biomedical Microdevices
Matthew Walker, Michel Godin, Andrew E Pelling
Although our understanding of cellular behavior in response to extracellular biological and mechanical stimuli has greatly advanced using conventional 2D cell culture methods, these techniques lack physiological relevance. To a cell, the extracellular environment of a 2D plastic petri dish is artificially flat, extremely rigid, static and void of matrix protein. In contrast, we developed the microtissue vacuum-actuated stretcher (MVAS) to probe cellular behavior within a 3D multicellular environment composed of innate matrix protein, and in response to continuous uniaxial stretch...
May 28, 2018: Biomedical Microdevices
Jiawei Zhou, Albert Kim, Babak Ziaie
In this paper, we present an ultrasonically controlled switching system that can save the battery power for implantable devices by turning the system on and off, on-demand. Ultrasonic control is employed to reduce the device size, increase the penetration depth, and reduce misalignment sensitivity associated with alternative techniques using permanent magnet and RF signal. As a proof-of-concept demonstration, a 665 kHz ultrasonic signal is used to activate a piezoelectric receiver which in turn switches a battery-powered RF system on-and-off...
May 23, 2018: Biomedical Microdevices
Ngoc M Pham, Sebastian Rusch, Yuksel Temiz, Robert D Lovchik, Hans-Peter Beck, Walter Karlen, Emmanuel Delamarche
Point-of-care (POC) diagnostics are critically needed for the detection of infectious diseases, particularly in remote settings where accurate and appropriate diagnosis can save lives. However, it is difficult to implement immunoassays, and specifically immunoassays relying on signal amplification using silver staining, into POC diagnostic devices. Effective immobilization of antibodies in such devices is another challenge. Here, we present strategies for immobilizing capture antibodies (cAbs) in capillary-driven microfluidic chips and implementing a gold-catalyzed silver staining reaction...
May 21, 2018: Biomedical Microdevices
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