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Xiaonan Xu, Haojun Yuan, Ruyuan Song, Miao Yu, Ho Yin Chung, Youmin Hou, Yuhe Shang, Hongbo Zhou, Shuhuai Yao
Droplet microfluidics, which involves micrometer-sized emulsion droplets on a microfabricated platform, has been demonstrated as a unique system for many biological and chemical applications. Robust and scalable generation of monodisperse droplets at high throughput is of fundamental importance for droplet microfluidics. Classic designs for droplet generation employ shear fluid dynamics to induce the breakup of droplets in a two-phase flow and the droplet size is sensitive to flow rate fluctuations, often resulting in polydispersity...
January 2018: Biomicrofluidics
Zeina S Khan, Julianna M Santos, Fazle Hussain
It has been hypothesized that highly metastatic cancer cells have softer nuclei and hence would travel faster through confining environments. Our goal was to prove this untested hypothesis for prostate cells. Our nuclear creep experiments using a microfluidic channel with a narrow constriction show that stiffness of aggressive immortalized prostate cancer nuclei is significantly lower than that of immortalized normal cell nuclei and hence can be a convenient malignancy marker. Nuclear stiffness is found to be the highest for cells expressing high levels of lamin A/C but lowest for cells expressing low lamin A/C levels...
January 2018: Biomicrofluidics
Christopher George Uhl, Vladimir R Muzykantov, Yaling Liu
Therapeutic delivery from microvasculature to cancerous sites is influenced by many factors including endothelial permeability, vascular flow rates/pressures, cancer secretion of cytokines and permeabilizing agents, and characteristics of the chosen therapeutics. This work uses bi-layer microfluidics capable of studying dye and therapeutic transport from a simulated vessel to a cancerous region while allowing for direct visualization and quantification of endothelial permeability. 2.5 to 13 times greater dye transport was observed when utilizing small dye sizes (FITC) when compared to larger molecules (FITC-Dextran 4 kDa and FITC-Dextran 70 kDa), respectively...
January 2018: Biomicrofluidics
Amir Hossein Raffiee, Sadegh Dabiri, Arezoo M Ardekani
In this paper, we study the dynamics of deformable cells in a channel flow of Newtonian and polymeric fluids and unravel the effects of deformability, elasticity, inertia, and size on the cell motion. We investigate the role of polymeric fluids on the cell migration behavior and the performance of inertial microfluidic devices. Our results show that the equilibrium position of the cell is on the channel diagonal, in contrast to that of rigid particles, which is on the center of the channel faces for the same range of Reynolds number...
November 2017: Biomicrofluidics
Kwangseok Park, Jinsoo Park, Jin Ho Jung, Ghulam Destgeer, Husnain Ahmed, Hyung Jin Sung
Droplets in microfluidic systems can contain microscale objects such as cells and microparticles. The control of the positions of microscale objects within a microchannel is crucial for practical applications in not only continuous-flow-based but also droplet-based systems. This paper proposes an active method for the separation of microparticles inside moving droplets which uses travelling surface acoustic waves (TSAWs). We demonstrate the preconcentration and separation of 5 and 10 μm polystyrene microparticles in moving water-in-oil droplets through the application of TSAWs with two different frequencies...
November 2017: Biomicrofluidics
J Cottet, C Vaillier, F Buret, M Frénéa-Robin, P Renaud
This paper describes a reproducible method for μm precision alignment of polydimethylsiloxane (PDMS) microchannels with coplanar electrodes using a conventional mask aligner for lab-on-a-chip applications. It is based on the use of a silicon mold in combination with a PMMA sarcophagus for precise control of the parallelism between the top and bottom surfaces of molded PDMS. The alignment of the fabricated PDMS slab with electrodes patterned on a glass chip is then performed using a conventional mask aligner with a custom-made steel chuck and magnets...
November 2017: Biomicrofluidics
Shigeru Tada, Masako Hayashi, Masanori Eguchi, Akira Tsukamoto
We propose a novel, high-performance dielectrophoretic (DEP) cell-separation flow chamber with a parallel-plate channel geometry. The flow chamber, consisting of a planar electrode on the top and an interdigitated-pair electrode array at the bottom, was developed to facilitate the separation of cells by creating a nonuniform AC electric field throughout the volume of the flow chamber. The operation and performance of the device were evaluated using live and dead human epithermal breast (MCF10A) cells. The separation dynamics of the cell suspension in the flow chamber was also investigated by numerically simulating the trajectories of individual cells...
November 2017: Biomicrofluidics
Farnaz Asayesh, Mir Pouyan Zarabadi, Jesse Greener
Specially designed microfluidic bioflow cells were used to temporarily trap microbubbles during different inoculation stages of Pseudomonas sp. biofilms. Despite being eliminated many hours before biofilm appearance, templated growth could occur at former bubble positions. Bubble-templated growth was either continuous or in ring patterns, depending on the stage of inoculation when the bubbles were introduced. Templated biofilms were strongly enhanced in terms of their growth kinetics and structural homogeneity...
November 2017: Biomicrofluidics
Ju-Ching Yu, Pang-Hsin Hsieh, Hsing-Wen Tsai, Wen-Hsin Chang, Ting-Hang Liu, Mel S Lee, Kuo-Ti Peng, Kuo-Chin Huang, Gwo-Bin Lee
Necrotic fasciitis (NF) is a particularly aggressive and serious infection of the fascia that can penetrate into the musculature and internal organs, resulting in death if not treated promptly. In this work, an integrated microfluidic system composed of micropumps, microvalves, and micromixers was used to automate the detection of pathogens associated with NF. The entire molecular diagnostic process, including bacteria isolation, lysis, nucleic acid amplification and optical detection steps, was enacted on this developed system...
November 2017: Biomicrofluidics
Min Ho Hwang, Dong Hyun Cho, Seung Min Baek, Jae Won Lee, Jeong Hun Park, Chang Min Yoo, Jae Hee Shin, Hyo Geun Nam, Hyeong Guk Son, Hyun Jung Lim, Han Sang Cho, Hong Joo Moon, Joo Han Kim, Jong Kwang Lee, Hyuk Choi
The aetiology of intervertebral disc (IVD) degeneration accompanied by low back pain (LBP) is largely unknown, and there are no effective fundamental therapies. Symptomatic IVD is known to be associated with nerve root compression. However, even in the absence of nerve compression, LBP occurs in patients with IVD degeneration. We hypothesize that this phenomenon is associated with a concentration of pro-inflammatory cytokines such as interleukin (IL)-1β and tumour necrosis factor-alpha (TNF-α), which can lead to altered histologic features and cellular phenotypes observed during IVD degeneration...
November 2017: Biomicrofluidics
Nesreen Z Alsmadi, Sarah J Shapiro, Christopher S Lewis, Vinit M Sheth, Trevor A Snyder, David W Schmidtke
Due to the critical roles that platelets play in thrombosis during many biological and pathological events, altered platelet function may be a key contributor to altered hemostasis, leading to both thrombotic and hemorrhagic complications. Platelet adhesion at arterial shear rates occurs through binding to von Willebrand Factor via the glycoprotein (GP) GPIb receptor. GPIb binding can induce platelet activation distinguishable by P-selectin (CD62P) surface expression and αIIbβ3 activation, resulting in platelet aggregation and formation of the primary hemostatic plug to stop bleeding...
November 2017: Biomicrofluidics
Zhen Xu, Yingjun Wang, Yuncong Chen, Martin H Spalding, Liang Dong
This paper reports on a microfluidic device capable of screening carbon dioxide (CO2) conditions for microalgal cell growth. The device mainly consists of a microfluidic cell culture (MCC) unit, a gas concentration gradient generator (CGG), and an in-line cell growth optical measurement unit. The MCC unit is structured with multiple aqueous-filled cell culture channels at the top layer, multiple CO2 flow channels at the bottom layer, and a commercial hydrophobic gas semipermeable membrane sandwiched between the two channel layers...
November 2017: Biomicrofluidics
Max A Stockslager, Josephine Shaw Bagnall, Vivian C Hecht, Kevin Hu, Edgar Aranda-Michel, Kristofor Payer, Robert J Kimmerling, Scott R Manalis
The physical characteristics of the T cell receptor (TCR)-peptide-major histocompatibility complex (pMHC) interaction are known to play a central role in determining T cell function in the initial stages of the adaptive immune response. State-of-the-art assays can probe the kinetics of this interaction with single-molecular-bond resolution, but this precision typically comes at the cost of low throughput, since the complexity of these measurements largely precludes "scaling up." Here, we explore the feasibility of detecting specific TCR-pMHC interactions by flowing T cells past immobilized pMHC and measuring the reduction in cell speed due to the mechanical force of the receptor-ligand interaction...
November 2017: Biomicrofluidics
Qi Chen, Di Li, Jessica Zielinski, Lukasz Kozubowski, Jianhan Lin, Maohua Wang, Xiangchun Xuan
Morphology is an important particle (both biological and synthetic) property and potentially a useful marker for label-free particle separation. We present in this work a continuous-flow morphology-based fractionation of a heterogeneous mixture of drug-treated yeast cells in dilute ferrofluids. Such a diamagnetic cell separation technique utilizes the negative magnetophoretic motion to direct pre-focused yeast cells to morphology-dependent streamlines in a laminar flow. The separation performance is evaluated by comparing the exiting positions of the four classified groups of yeast cells: Singles, Doubles, Triples, and Others...
November 2017: Biomicrofluidics
Yuan Jia, Hui Dong, Jianping Zheng, Hao Sun
Particulate matter (PM), a key indicator of air pollution by natural and anthropogenic activities, contributes to a wide spectrum of diseases that lead to a shortening of life expectancy. It has been recognized that trace metals in airborne PM are highly toxic and can be correlated with lesion in respiratory, gastrointestinal, immunological, and hematological systems. Traditional methods for trace metal assay require sophisticated instrumentations and highly trained operators in centralized laboratories. In this work, by integrating the technologies of microfluidic paper-based analytical devices, additive manufacturing, smartphone, and colorimetric sensing, we developed the first smartphone based paper microfluidic platform for portable, disposable, and quantitative measurements of cobalt (Co), copper (Cu), and iron (Fe) in ambient air and street sediments...
November 2017: Biomicrofluidics
Remo Freimann, Anton Wutz
Hemizygous mutations introduced in haploid genomes can directly expose a phenotype, thus facilitating gene function analysis and forward genetic screening. Recently, mammalian haploid cells could be derived from mouse, rat, monkey, and human embryos and have been applied to screens of cellular mechanisms including cell signaling, pathogen host factors, and developmental pathways. Notably, haploid cell cultures have an intrinsic tendency for diploidization and, thus, require periodic cell sorting. Here, we report a method for rapid purification of haploid mouse embryonic stem cells from mixed cell populations with high viability and yield...
September 2017: Biomicrofluidics
Matthew B Byrne, Matthew T Leslie, Heeral S Patel, H Rex Gaskins, Paul J A Kenis
Regions of hypoxia are common in solid tumors and are associated with enhanced malignancy, metastasis, and chemo/radio resistance. Real-time hypoxic cellular experimentation is challenging due to the constant need for oxygen control. Most microfluidic platforms developed thus far for hypoxic cell studies are burdened by complex design parameters and are difficult to use for uninitiated investigators. However, open-well microfluidic platforms enable short and long term hypoxic cell studies with an ease of use workflow...
September 2017: Biomicrofluidics
Gergely Simon, Marco A B Andrade, Julien Reboud, Jose Marques-Hueso, Marc P Y Desmulliez, Jonathan M Cooper, Mathis O Riehle, Anne L Bernassau
High efficiency isolation of cells or particles from a heterogeneous mixture is a critical processing step in lab-on-a-chip devices. Acoustic techniques offer contactless and label-free manipulation, preserve viability of biological cells, and provide versatility as the applied electrical signal can be adapted to various scenarios. Conventional acoustic separation methods use time-of-flight and achieve separation up to distances of quarter wavelength with limited separation power due to slow gradients in the force...
September 2017: Biomicrofluidics
Elif Gencturk, Senol Mutlu, Kutlu O Ulgen
Silicon and glass were the main fabrication materials of microfluidic devices, however, plastics are on the rise in the past few years. Thermoplastic materials have recently been used to fabricate microfluidic platforms to perform experiments on cellular studies or environmental monitoring, with low cost disposable devices. This review describes the present state of the development and applications of microfluidic systems used in cell biology and analyses since the year 2000. Cultivation, separation/isolation, detection and analysis, and reaction studies are extensively discussed, considering only microorganisms (bacteria, yeast, fungi, zebra fish, etc...
September 2017: Biomicrofluidics
I Montasser, A W Coleman, Y Tauran, G Perret, L Jalabert, D Collard, B J Kim, M C Tarhan
We examine the effect of physiological cations Na(+), K(+), Mg(2+), and Ca(2+) on the mechanical properties of bundles of λ-phage DNA using silicon nanotweezers (SNTs). Integrating SNTs with a microfluidic device allows us to perform titration experiments while measuring the effect in real-time. The results show that only for Mg(2+) and in particular, at the intra-nuclear concentration (100 mM), the interaction occurs.
September 2017: Biomicrofluidics
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