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Biomedical Microdevices

Pei Liu, Yisi Zhu, Seung Hee Lee, Minhee Yun
In this work, we report a flexible field-effect-transistor (FET) biosensor design based on two-dimensional (2-D) polyaniline (PANI) nanostructure. The flexible biosensor devices were fabricated through a facile and inexpensive method that combines top-down and bottom-up processes. The chemically synthesized PANI nanostructure showed excellent p-type semiconductor properties as well as good compatibility with flexible design. With the 2-D PANI nanostructure being as thin as 80 nm and its extremely large surface-area-to-volume (SA/V) ratio due to the intrinsic properties of PANI chemical synthesis, the developed flexible biosensor exhibited outstanding sensing performance in detecting B-type natriuretic peptide (BNP) biomarkers, and was able to achieve high specificity (averagely 112 folds) with the limit of detection as low as 100 pg/mL...
December 2016: Biomedical Microdevices
Wenwen Yi, Yuanyuan Yang, Parastoo Hashemi, Mark Ming-Cheng Cheng
In this paper, we have fabricated 3D carbon nanofiber microelectrode arrays (MEAs) with highly reproducible and rich chemical surface areas for fast scan cyclic voltammetry (FSCV). Carbon nanofibers are created from negative photoresist by a new process called dual O2 plasma-assisted pyrolysis. The proposed approach significantly improves film adhesion and increases surface reactivity. We showcase our sensor's compatibility with FSCV analysis by demonstrating highly sensitive and stable FSCV dopamine measurements on a prototype 4-channel array...
December 2016: Biomedical Microdevices
Durga Prakash Matta, Suryasnata Tripathy, Siva Rama Krishna Vanjari, Chandra Shekhar Sharma, Shiv Govind Singh
We report the fabrication of a label free nano biosensor platform comprising single nanofiber that is derived out of multi-walled carbon nanotubes (MWCNTs) embedded SU-8 photoresist, for the detection of three important human cardiac biomarkers viz., myoglobin (Myo), cardiac Troponin I (cTn I) and Creatine Kinase-MB (CK-MB). These composite nanofibers were synthesized using electrospinning process. Single nanofibers were aligned between pairs of electrodes in-situ during the electrospinning process. The target proteins were detected using chemiresistive detection methodology...
December 2016: Biomedical Microdevices
Jingjing Wang, Lihao Wang, Yinfang Zhu, Jinying Zhang, Ju Liao, Shuaipeng Wang, Jinling Yang, Fuhua Yang
Early liver cancer diagnosis has clinical significance in treating cancer. Joint detection of multiple biomarkers has been considered as an effective and reliable method for early cancer diagnosis. In this work, a novel biosensor based on microcantilever array was batch-fabricated for multiple liver cancer biomarkers detection with high sensitivity, high accuracy, high throughput, and high specification. A micro-cavity was designed in the free end of the cantilever for local reaction between antibody and antigen, which can dramatically reduce the effect of adsorption-induced stiffness coefficient k variation...
December 2016: Biomedical Microdevices
Sravani Kondapavulur, Andre M Cote, Kiel D Neumann, Caroline D Jordan, David McCoy, Marc C Mabray, Derek Liu, Chia-Hung Sze, Ayushi Gautam, Henry F VanBrocklin, Mark Wilson, Steven W Hetts
To computationally optimize the design of an endovascular magnetic filtration device that binds iron oxide nanoparticles and to validate simulations with experimental results of prototype devices in physiologic flow testing. Three-dimensional computational models of different endovascular magnetic filter devices assessed magnetic particle capture. We simulated a series of cylindrical neodymium N52 magnets and capture of 1500 iron oxide nanoparticles infused in a simulated 14 mm-diameter vessel. Device parameters varied included: magnetization orientation (across the diameter, "D", along the length, "L", of the filter), magnet outer diameter (3, 4, 5 mm), magnet length (5, 10 mm), and spacing between magnets (1, 3 mm)...
December 2016: Biomedical Microdevices
Elisabetta Esposito, Markus Drechsler, Nicolas Huang, Gabriella Pavoni, Rita Cortesi, Debora Santonocito, Carmelo Puglia
The present study describes the production and characterization of phosphatidylcholine based ethosomes and organogels, as percutaneous delivery systems for crocin. Crocin presence did not influence ethosome morphology, while the drug slightly increased ethosome mean diameter. Importantly, the poor chemical stability of crocin has been found to be long controlled by organogel. To investigate the performance of phosphatidylcholine lipid formulations as crocin delivery system, in vivo studies, based on tape stripping and skin reflectance spectrophotometry, were performed...
December 2016: Biomedical Microdevices
Wenguang Yang, Haibo Yu, Gongxin Li, Yuechao Wang, Lianqing Liu
Poly(ethylene glycol) diacrylate (PEGDA) is a common hydrogel that has been actively investigated for various tissue engineering applications owing to its biocompatibility and excellent mechanical properties. However, the native PEGDA films are known for their bio-inertness which can hinder cell adhesion, thereby limiting their applications in tissue engineering and biomedicine. Recently, nano composite technology has become a particularly hot topic, and has led to the development of new methods for delivering desired properties to nanomaterials...
December 2016: Biomedical Microdevices
Christoph Bechtold, Rodrigo Lima de Miranda, Christoph Chluba, Eckhard Quandt
Self-expandable medical devices provide mechanical functionality at a specific location of the human body and are viable for minimal invasive procedures. Besides radiopaque markers and drug-eluting coatings, next generation self-expandable devices can be equipped with additional functionality, such as conductive and flexible electrodes, which enables chronic recording of bioelectrical signals, stimulating or ablating tissue. This promises new therapeutic options in various medical fields, among them in particular neuromodulation (e...
December 2016: Biomedical Microdevices
Cole R Drifka, Agnes G Loeffler, Corinne R Esquibel, Sharon M Weber, Kevin W Eliceiri, W John Kao
A hallmark of pancreatic ductal adenocarcinoma (PDAC) is the ability for cancer cells to aggressively infiltrate and navigate through a dense stroma during the metastatic process. Key features of the PDAC stroma include an abundant population of activated pancreatic stellate cells (PSCs) and highly aligned collagen fibers; however, important questions remain regarding how collagen becomes aligned and what the biological manifestations are. To better understand how PSCs, aligned collagen, and PDAC cells might cooperate during the transition to invasion, we utilized a microchannel-based in vitro tumor model and advanced imaging technologies to recreate and examine in vivo-like heterotypic interactions...
December 2016: Biomedical Microdevices
Jennifer Campbell, Christine McBeth, Maxim Kalashnikov, Anna K Boardman, Andre Sharon, Alexis F Sauer-Budge
A strong natural selection for microbial antibiotic resistance has resulted from the extensive use and misuse of antibiotics. Though multiple factors are responsible for this crisis, the most significant factor - widespread prescription of broad-spectrum antibiotics - is largely driven by the fact that the standard process for determining antibiotic susceptibility includes a 1-2-day culture period, resulting in 48-72 h from patient sample to final determination. Clearly, disruptive approaches, rather than small incremental gains, are needed to address this issue...
December 2016: Biomedical Microdevices
Xueye Chen, Jienan Shen, Zengliang Hu, Xuyao Huo
Applications of membranes in microfluidics solved many thorny problems for analytical chemistry and bioscience, so that the use of membranes in microfluidics has been a topic of growing interest. Many different examples have been reported, demonstrating the versatile use of membranes. This work reviews a lot of applications of membranes in microfluidics. Membranes in microfluidics for applications including chemical reagents detection, gas detection, drug screening, cell, protein, microreactor, electrokinetical fluid, pump and valve and fluid transport control and so on, have been analyzed and discussed...
December 2016: Biomedical Microdevices
Hao Zhou, Gursel Alici, Fredy Munoz
In this study, we propose a new magnetically actuated anchoring system for wireless capsule endoscopes (WCE) by employing the principle of a switchable magnetic spring. A force model is derived to predict the magnetic force needed to support the interaction between the anchors and the intestinal lumen. The theoretical and experimental analysis conducted shows that the magnetic spring is capable of providing the force needed to activate the anchoring mechanism, which consists of four foldable legs. A prototype capsule with a size comparable with the size of a commercial WCE was designed, fabricated, and tested...
December 2016: Biomedical Microdevices
Whui Lyn Then, Heather McLiesh, Marie-Isabel Aguilar, Gil Garnier
The most widely known blood groups, ABO and RhD, have been extensively observed as having strong antibody-antigen interactions during blood typing. However, not all interactions show the same binding affinity. The Duffy blood group system, where Fy(a) and Fy(b) antigens are the most clinically significant, are only available with an IgG antibody structure, and display weak binding interactions. While current blood typing techniques are well established, methods for quantifying the binding strength are more limited...
December 2016: Biomedical Microdevices
Wlodek Mandecki, Efrain Frank Rodriguez, Julie Drawbridge
Collecting information about biochemical processes occurring inside a single cell or embryo is traditionally done either using fluorescent dyes with microscopy or via microelectrode voltage-clamp techniques. This paper demonstrates that a more direct method - transmission of information using an electronic chip implanted in an embryo - is feasible. A light-activated microtransponder with dimensions 250 μm × 250 μm × 100 μm (a "p-Chip") was implanted into a blastula-stage frog (Xenopus laevis) embryo...
December 2016: Biomedical Microdevices
Qianghua Quan, Shuwen Zhang, Xudong Wang, Qi Ouyang, Yugang Wang, Gen Yang, Chunxiong Luo
Cell migration assays for different chemical environments are important for both scientists and clinicians searching for new therapeutics. In this study, we developed a multi-well-based microfluidic chip that has multiple units for different conditions. In each unit, cells can be patterned and then released to observe their migration. Automatic image analysis and model-based data processing were developed to describe the integrated cell migration assay precisely and quickly. As a demonstration, the migration behaviors of two types of cells in eight chemical conditions were studied...
December 2016: Biomedical Microdevices
Mariam S Aboian, Jay F Yu, Ayushi Gautam, Chia-Hung Sze, Jeffrey K Yang, Jonathan Chan, Prasheel V Lillaney, Caroline D Jordan, Hee-Jeung Oh, David M Wilson, Anand S Patel, Mark W Wilson, Steven W Hetts
To report a novel method using immobilized DNA within mesh to sequester drugs that have intrinsic DNA binding characteristics directly from flowing blood. DNA binding experiments were carried out in vitro with doxorubicin in saline (PBS solution), porcine serum, and porcine blood. Genomic DNA was used to identify the concentration of DNA that shows optimum binding clearance of doxorubicin from solution. Doxorubicin binding kinetics by DNA enclosed within porous mesh bags was evaluated. Flow model simulating blood flow in the inferior vena cava was used to determine in vitro binding kinetics between doxorubicin and DNA...
December 2016: Biomedical Microdevices
Rakesh Khilwani, Peter J Gilgunn, Takashi D Y Kozai, Xiao Chuan Ong, Emrullah Korkmaz, Pallavi K Gunalan, X Tracy Cui, Gary K Fedder, O Burak Ozdoganlar
Stable chronic functionality of intracortical probes is of utmost importance toward realizing clinical application of brain-machine interfaces. Sustained immune response from the brain tissue to the neural probes is one of the major challenges that hinder stable chronic functionality. There is a growing body of evidence in the literature that highly compliant neural probes with sub-cellular dimensions may significantly reduce the foreign-body response, thereby enhancing long term stability of intracortical recordings...
December 2016: Biomedical Microdevices
V N Lad, Swati Ralekar
Development of controlled vacuum is having many applications in the realm of biotechnology, cell transfer, gene therapy, biomedical engineering and other engineering activities involving separation or chemical reactions. Here we show the controlled vacuum generation through a biocompatible, energy efficient, low-cost and flexible miniature device. We have designed and fabricated microfluidic devices from polydimethylsiloxane which are capable of producing vacuum at a highly controlled rate by using water as a motive fluid...
October 2016: Biomedical Microdevices
Sowmya Subramanian, Konstantinos Gerasopoulos, Min Guo, Herman O Sintim, William E Bentley, Reza Ghodssi
Bacterial biofilms are a common cause of chronic medical implant infections. Treatment and eradication of biofilms by conventional antibiotic therapy has major drawbacks including toxicity and side effects associated with high-dosage antibiotics. Additionally, administration of high doses of antibiotics may facilitate the emergence of antibiotic resistant bacteria. Thus, there is an urgent need for the development of treatments that are not based on conventional antibiotic therapies. Presented herein is a novel bacterial biofilm combination treatment independent of traditional antibiotics, by using low electric fields in combination with small molecule inhibitors of bacterial quorum sensing - autoinducer-2 analogs...
October 2016: Biomedical Microdevices
Ning Hu, Jiaru Fang, Ling Zou, Hao Wan, Yuxiang Pan, Kaiqi Su, Xi Zhang, Ping Wang
Cell-based bioassays were effective method to assess the compound toxicity by cell viability, and the traditional label-based methods missed much information of cell growth due to endpoint detection, while the higher throughputs were demanded to obtain dynamic information. Cell-based biosensor methods can dynamically and continuously monitor with cell viability, however, the dynamic information was often ignored or seldom utilized in the toxin and drug assessment. Here, we reported a high-efficient and high-content cytotoxic recording method via dynamic and continuous cell-based impedance biosensor technology...
October 2016: Biomedical Microdevices
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