Shi, Mingjian; Majumdar, Devi; Gao, Yandong; Brewer, Bryson M; Goodwin, Cody R; McLean, John A; Li, Deyu; Webb, Donna J
Two novel microfluidic cell culture schemes, a vertically-layered set-up and a four chamber set-up, were developed for co-culturing central nervous system (CNS) neurons and glia. The cell chambers in these devices were separated by pressure-enabled valve barriers, which permitted us to control communication between the two cell types. The unique design of these devices facilitated the co-culture of glia with neurons in close proximity (∼50-100 μm), differential transfection of neuronal populations, and dynamic visualization of neuronal interactions, such as the development of synapses. With these co-culture devices, initial synaptic contact between neurons transfected with different fluorescent markers, such as green fluorescent protein (GFP) and mCherry-synaptophysin, was imaged using high-resolution fluorescence microscopy. The presence of glial cells had a profound influence on synapses by increasing the number and stability of synaptic contacts. Interestingly, as determined by liquid chromatography-ion mobility-mass spectrometry, neuron-glia co-cultures produced elevated levels of soluble factors compared to that secreted by individual neuron or glia cultures, suggesting a potential mechanism by which neuron-glia interactions could modulate synaptic function. Collectively, these results show that communication between neurons and glia is critical for the formation and stability of synapses and point to the importance of developing neuron-glia co-culture systems such as the microfluidic platforms described in this study.
Fernandes, João T S; Chutna, Oldriska; Chu, Virginia; Conde, João P; Outeiro, Tiago F
Although, the precise molecular mechanisms underlying Parkinson's disease (PD) are still elusive, it is now known that spreading of alpha-synuclein (aSyn) pathology and neuroinflammation are important players in disease progression. Here, we developed a novel microfluidic cell-culture platform for studying the communication between two different cell populations, a process of critical importance not only in PD but also in many biological processes. The integration of micro-valves in the device enabled us to control fluid routing, cellular microenvironments, and to simulate paracrine signaling. As proof of concept, two sets of experiments were designed to show how this platform can be used to investigate specific molecular mechanisms associated with PD. In one experiment, naïve H4 neuroglioma cells were co-cultured with cells expressing aSyn tagged with GFP (aSyn-GFP), to study the release and spreading of the protein. In our experimental set up, we induced the release of the contents of aSyn-GFP producing cells to the medium and monitored the protein's diffusion. In another experiment, H4 cells were co-cultured with N9 microglial cells to assess the interplay between two cell lines in response to environmental stimuli. Here, we observed an increase in the levels of reactive oxygen species in H4 cells cultured in the presence of activated N9 cells, confirming the cross talk between different cell populations. In summary, the platform developed in this study affords novel opportunities for the study of the molecular mechanisms involved in PD and other neurodegenerative diseases.
Microfluidic devices are popular tools in the biotechnology industry where they provide smaller reagent requirements, high speed of analysis and the possibility for automation. The aim of the project is to make a flexible biocompatible microfluidic platform adapted to different specific applications, mainly analytical and separations which parameters and configuration can be changed multiple times by changing corresponding computer programme. The current project has been sup...
Burger, Robert; Amato, Letizia; Boisen, Anja
Centrifugal microfluidics has attracted much interest from academia as well as industry, since it potentially offers solutions for affordable, user-friendly and portable biosensing. A wide range of so-called fluidic unit operations, e.g. mixing, metering, liquid routing, and particle separation...... for the centrifugal microfluidics platform and cover optical as well as mechanical and electrical detection principles....
Benett, William [Livermore, CA; Krulevitch, Peter [Pleasanton, CA; Maghribi, Mariam [Livermore, CA; Hamilton, Julie [Tracy, CA; Rose, Klint [Boston, MA; Wang, Amy W [Oakland, CA
A method of forming a polymer-based microfluidic system platform using network building blocks selected from a set of interconnectable network building blocks, such as wire, pins, blocks, and interconnects. The selected building blocks are interconnectably assembled and fixedly positioned in precise positions in a mold cavity of a mold frame to construct a three-dimensional model construction of a microfluidic flow path network preferably having meso-scale dimensions. A hardenable liquid, such as poly (dimethylsiloxane) is then introduced into the mold cavity and hardened to form a platform structure as well as to mold the microfluidic flow path network having channels, reservoirs and ports. Pre-fabricated elbows, T's and other joints are used to interconnect various building block elements together. After hardening the liquid the building blocks are removed from the platform structure to make available the channels, cavities and ports within the platform structure. Microdevices may be embedded within the cast polymer-based platform, or bonded to the platform structure subsequent to molding, to create an integrated microfluidic system. In this manner, the new microfluidic platform is versatile and capable of quickly generating prototype systems, and could easily be adapted to a manufacturing setting.
Micro- and Nanotechnology have the potential to offer a smart solution for diagnostics and academia research with rapid, low cost, robust analysis systems to facilitate biological analyses. New, high throughput microfluidic platforms have the potential to surpass in performance the conventional...... analyses systems in use today. The overall goal of this PhD project is to address two different areas using microfluidics : i) Chromosome analysis by metaphase FISH such a platform, if successful, can immediately substitute the routine, labor-intensive, glass slide-based FISH analyses in Clinical...... Cytogenetics laboratories. During the course of this project, initially the suitability of the polymeric chip substrate was tested and a microfluidic device was developed for performing interphase FISH analysis. With this device, the key factors involved in chromosome spreading crucial to FISH analysis were...
van den Brink, Floris Teunis Gerardus; Gool, Elmar; Frimat, Jean-Philippe; Bomer, Johan G.; van den Berg, Albert; le Gac, Severine
We report a PDMS microfluidic platform for parallel single-cell analysis (PaSCAl) as a powerful tool to decipher the heterogeneity found in cell populations. Cells are trapped individually in dedicated pockets, and thereafter, a number of invasive or non-invasive analysis schemes are performed.
Full Text Available is also offered as numerous devices can be implemented on one disc. A variety of components from sample preparation through to detection can be implemented simply and effectively into an integrated microfluidic solution for life sciences. The lab... in the field of centrifugal microfluidics. New microfluidic platform for life sciences in South Africa S. HUGO, K. LAND CSIR Materials Science and Manufacturing P O Box 395, Pretoria 0001, SOUTH AFRICA Email: firstname.lastname@example.org INTRODUCTION Microfluidic...
Vittayarukskul, Kevin; Lee, Abraham Phillip
Ideally, a modular microfluidics platform should be simple to assemble and support 3D configurations for increased versatility. The modular building blocks should also be mass producible like electrical components. These are fundamental features of world-renowned Legos® and why Legos® inspire many existing modular microfluidics platforms. In this paper, a truly Lego®-like microfluidics platform is introduced, and its basic feasibility is demonstrated. Here, PDMS building blocks resembling 2 × 2 Lego® bricks are cast from 3D-printed master molds. The blocks are pegged and stacked on a traditional Lego® plate to create simple, 3D microfluidic networks, such as a single basket weave. Characteristics of the platform, including reversible sealing and automatic alignment of channels, are also analyzed and discussed in detail.
Vittayarukskul, Kevin; Lee, Abraham Phillip
Ideally, a modular microfluidics platform should be simple to assemble and support 3D configurations for increased versatility. The modular building blocks should also be mass producible like electrical components. These are fundamental features of world-renowned Legos ® and why Legos ® inspire many existing modular microfluidics platforms. In this paper, a truly Lego ® -like microfluidics platform is introduced, and its basic feasibility is demonstrated. Here, PDMS building blocks resembling 2 × 2 Lego ® bricks are cast from 3D-printed master molds. The blocks are pegged and stacked on a traditional Lego ® plate to create simple, 3D microfluidic networks, such as a single basket weave. Characteristics of the platform, including reversible sealing and automatic alignment of channels, are also analyzed and discussed in detail. (paper)
Chung, Chih-Yao; Wang, Jhih-Cheng; Chuang, Han-Sheng
Successful treatments against bacterial infections depend on antimicrobial susceptibility testing (AST). However, conventional AST requires more than 24 h to obtain an outcome, thereby contributing to high patient mortality. An antibiotic therapy based on experiences is therefore necessary for saving lives and escalating the emergence of multidrug-resistant pathogens. Accordingly, a fast and effective drug screen is necessary for the appropriate administration of antibiotics. The mixed pathogenic nature of infectious diseases emphasizes the need to develop an assay system for polymicrobial infections. On this basis, we present a novel technique for simultaneous and quantitative monitoring of co-cultured microorganisms by coupling optical diffusometry with bead-based immunoassays. This simple integration simultaneously achieves a rapid AST analysis for two pathogens. Triple color particles were simultaneously recorded and subsequently analyzed by functionalizing different fluorescent color particles with dissimilar pathogen-specific antibodies. Results suggested that the effect of the antibiotic, gentamicin, on co-cultured Pseudomonas aeruginosa and Staphylococcus aureus was effectively distinguished by the proposed technique. This study revealed a multiplexed and time-saving (within 2 h) platform with a small sample volume (~0.5 μL) and a low initial bacterial count (50 CFU per droplet, ~105 CFU/mL) for continuously monitoring the growth of co-cultured microorganisms. This technique provides insights into timely therapies against polymicrobial diseases in the near future.
This PhD thesis demonstrates (i) centrifugal microfluidics disc platform integrated with Au capped nanopillar (NP) substrates for surface-enhanced Raman spectroscopy (SERS) based sensing, and (ii) novel sample analysis concepts achieved by synergistical combination of sensing techniques and minia......This PhD thesis demonstrates (i) centrifugal microfluidics disc platform integrated with Au capped nanopillar (NP) substrates for surface-enhanced Raman spectroscopy (SERS) based sensing, and (ii) novel sample analysis concepts achieved by synergistical combination of sensing techniques...... dense array of NP structures. Furthermore, the wicking assisted nanofiltration procedure was accomplished in centrifugal microfluidics platform and as a result additional sample purification was achieved through the centrifugation process. In this way, the Au coated NP substrate was utilized...
Gach, Philip C; Shih, Steve C C; Sustarich, Jess; Keasling, Jay D; Hillson, Nathan J; Adams, Paul D; Singh, Anup K
We present a water-in-oil droplet microfluidic platform for transformation, culture and expression of recombinant proteins in multiple host organisms including bacteria, yeast and fungi. The platform consists of a hybrid digital microfluidic/channel-based droplet chip with integrated temperature control to allow complete automation and integration of plasmid addition, heat-shock transformation, addition of selection medium, culture, and protein expression. The microfluidic format permitted significant reduction in consumption (100-fold) of expensive reagents such as DNA and enzymes compared to the benchtop method. The chip contains a channel to continuously replenish oil to the culture chamber to provide a fresh supply of oxygen to the cells for long-term (∼5 days) cell culture. The flow channel also replenished oil lost to evaporation and increased the number of droplets that could be processed and cultured. The platform was validated by transforming several plasmids into Escherichia coli including plasmids containing genes for fluorescent proteins GFP, BFP and RFP; plasmids with selectable markers for ampicillin or kanamycin resistance; and a Golden Gate DNA assembly reaction. We also demonstrate the applicability of this platform for transformation in widely used eukaryotic organisms such as Saccharomyces cerevisiae and Aspergillus niger. Duration and temperatures of the microfluidic heat-shock procedures were optimized to yield transformation efficiencies comparable to those obtained by benchtop methods with a throughput up to 6 droplets/min. The proposed platform offers potential for automation of molecular biology experiments significantly reducing cost, time and variability while improving throughput.
Andreasen, Sune Zoëga; Burger, Robert; Emnéus, Jenny
Here we present a pump-less microfluidic pla>orm which performs sample clean-up and enrichment in a single step, by integraAng Supported Liquid Membrane (SLM) extracAon. Our pla>orm offers a simple, yet very efficient, method for achieving sample pre-treatment and enrichment of rare analytes, in ...
the specialized laboratory. Microfluidic cell migration devices, imitating in vivo conditions were developed with success, improving the in vitro experimental setup for basic research and drug discovery. Polymer biosensors have reached a new level of maturity, and pathogen detection could benefit from...
Geng, Tao; Smallwood, Chuck R.; Zhu, Ying; Bredeweg, Erin L.; Baker, Scott E.; Evans, James E.; Kelly, Ryan T.
Modern live-cell imaging approaches permit real-time visualization of biological processes. However, limitations for unicellular organism trapping, culturing and long-term imaging can preclude complete understanding of how such microorganisms respond to perturbations in their local environment or linking single-cell variability to whole population dynamics. We have developed microfluidic platforms to overcome prior technical bottlenecks to allow both chemostat and compartmentalized cellular growth conditions using the same device. Additionally, a nanowell-based platform enables a high throughput approach to scale up compartmentalized imaging optimized within the microfluidic device. These channel and nanowell platforms are complementary, and both provide fine control over the local environment as well as the ability to add/replace media components at any experimental time point.
Malik, Sarul; Balyan, Prerna; Akhtar, J.; Agarwal, Ajay
Cell sorting and separation are considered to be very crucial preparatory steps for numerous clinical diagnostics and therapeutics applications in cell biology research arena. Label free cell separation techniques acceptance rate has been increased to multifold by various research groups. Size based cell separation method focuses on the intrinsic properties of the cell which not only avoids clogging issues associated with mechanical and centrifugation filtration methods but also reduces the overall cost for the process. Consequentially flow based cell separation method for continuous flow has attracted the attention of millions. Due to the realization of structures close to particle size in micro dimensions, the microfluidic devices offer precise and rapid particle manipulation which ultimately leads to an extraordinary cell separation results. The proposed microfluidic device is fabricated to separate polystyrene beads of size 1 µm, 5 µm, 10 µm and 20 µm. The actual dimensions of blood corpuscles were kept in mind while deciding the particle size of polystyrene beads which are used as a model particles for study.
In this thesis a lab on a chip platform is described which is capable of electrofusing cells in a picoliter droplet. The platform consist out of glass part containing recessed platinum electrodes plasma bonded to a PDMS slab containing microchannels. First the two cell populations are introduced
Ajit, Smrithi; Praveen, Hemanth Mithun; Puneeth, S. B.; Dave, Abhishek; Sesham, Bharat; Mohan, K. N.; Goel, Sanket
Today, Polymerase Chain Reaction (PCR) based DNA amplification plays an indispensable role in the field of biomedical research. Its inherent ability to exponentially amplify sample DNA has proven useful for the identification of virulent pathogens like those causing Multiple Drug-Resistant Tuberculosis (MDR-TB). The intervention of Microfluidics technology has revolutionized the concept of PCR from being a laborious and time consuming process into one that is faster, easily portable and capable of being multifunctional. The Microfluidics based PCR outweighs its traditional counterpart in terms of flexibility of varying reaction rate, operation simplicity, need of a fraction of volume and capability of being integrated with other functional elements. The scope of the present work involves the development of a real-time continuous flow microfluidic device, fabricated by 3D printing-governed rapid prototyping method, eventually leading to an automated and robust platform to process multiple DNA samples for detection of MDRTB-associated mutations. The thermal gradient characteristic to the PCR process is produced using peltier units appropriate to the microfluidic environment fully monitored and controlled by a low cost controller driven by a Data Acquisition System. The process efficiency achieved in the microfluidic environment in terms of output per cycle is expected to be on par with the traditional PCR and capable of earning the additional advantages of being faster and minimizing the handling.
Full Text Available The Franz diffusion cell is one of the most widely used devices to evaluate transdermal drug delivery. However, this static and nonflowing system has some limitations, such as a relatively large solution volume and skin area and the development of gas bubbles during sampling. To overcome these disadvantages, this study provides a proof of concept for miniaturizing models of transdermal delivery by using a microfluidic chip combined with a diffusion cell. The proposed diffusion microchip system requires only 80 μL of sample solution and provides flow circulation. Two model compounds, Coomassie Brilliant Blue G-250 and potassium ferricyanide, were successfully tested for transdermal delivery experiments. The diffusion rate is high for a high sample concentration or a large membrane pore size. The developed diffusion microchip system, which is feasible, can be applied for transdermal measurement in the future.
Figueras-Mari, I.; Rodriguez-Trujillo, L.; Samitier-Marti, J.
Circulating tumor cells (CTCs) are released from primary tumors into the bloodstream and transported to distant organs, promoting metastasis, which is known to be responsible for most cancer‐related deaths. Currently tumors are not found until symptoms appear or by chance when the patient undergoes a medical test, which in both situations can be too late. Once a tumor is found it is studied from tissue samples obtained directly from the patient in an invasive way. This invasive procedure is known as biopsy and apart from being invasive, it is costly, time consuming and can sometimes be painful and even risky for the patients’ health condition. Therefore, CTCs detection in blood also addressed as “liquid biopsy” would be very useful because by running routine blood analysis CTCs could be detected and collected suggesting tumor presence. However, due to the scarce presence in blood of these cells and to the huge amount of contamination from other cellular components a perfect method providing good capture and purity of CTCs has not been developed yet. In this project, a spiral size sorter microfluidic device has been manufactured and tested in order to determine its performance and limitations. Device performance was tested with different dilutions of healthy donor blood samples mixed with 30 micron particles simulating CTCs. The results obtained from these experiments show very good CTC recovery of up to 100% and the depletion of blood cellular components is around 99.9%. (Author)
Ferraro, Davide; Champ, Jérôme; Teste, Bruno; Serra, M; Malaquin, Laurent; Descroix, Stéphanie; de Cremoux, Patricia; Viovy, Jean-Louis
Analyses of nucleic acids are routinely performed in hospital laboratories to detect gene alterations for cancer diagnosis and treatment decision. Among the different possible investigations, mRNA analysis provides information on abnormal levels of genes expression. Standard laboratory methods are still not adapted to the isolation and quantitation of low mRNA amounts and new techniques needs to be developed in particular for rare subsets analysis. By reducing the volume involved, time process, and the contamination risks, droplet microfluidics provide numerous advantages to perform analysis down to the single cell level.We report on a droplet microfluidic platform based on the manipulation of magnetic particles that allows the clinical analysis of tumor tissues. In particular, it allows the extraction of mRNA from the total-RNA sample, Reverse Transcription, and cDNA amplification, all in droplets.
Microfluidic platforms are well-suited for biomedical analysis and usually consist of a set of units which guarantee the manipulation, detection and recognition of bioanalyte in a reliable and flexible manner. Additionally, the use of magnetic fields for perfoming the aforementioned tasks has been steadily gainining interest. This is due to the fact that magnetic fields can be well tuned and applied either externally or from a directly integrated solution in the diagnostic system. In combination with these applied magnetic fields, magnetic nanoparticles are used. In this paper, we present some of our most recent results in research towards a) microfluidic diagnostics using MR sensors and magnetic particles and b) single cell analysis using magnetic particles. We have successfully manipulated magnetically labeled bacteria and measured their response with integrated GMR sensors and we have also managed to separate magnetically labeled jurkat cells for single cell analysis. © 2015 Trans Tech Publications, Switzerland.
Stipsitz, Martin; Kokkinis, Georgios; Gooneratne, Chinthaka Pasan; Kosel, Jü rgen; Cardoso, Susana; Cardoso, Filipe; Giouroudi, Ioanna
Microfluidic platforms are well-suited for biomedical analysis and usually consist of a set of units which guarantee the manipulation, detection and recognition of bioanalyte in a reliable and flexible manner. Additionally, the use of magnetic fields for perfoming the aforementioned tasks has been steadily gainining interest. This is due to the fact that magnetic fields can be well tuned and applied either externally or from a directly integrated solution in the diagnostic system. In combination with these applied magnetic fields, magnetic nanoparticles are used. In this paper, we present some of our most recent results in research towards a) microfluidic diagnostics using MR sensors and magnetic particles and b) single cell analysis using magnetic particles. We have successfully manipulated magnetically labeled bacteria and measured their response with integrated GMR sensors and we have also managed to separate magnetically labeled jurkat cells for single cell analysis. © 2015 Trans Tech Publications, Switzerland.
Cardoso, F. A.; Martins, V. C.; Fonseca, L. P.; Germano, J.; Sousa, L. A.; Piedade, M. S.; Freitas, P. P.
Faster, more sensitive and easy to operate biosensing devices still are a need at important areas such as biomedical diagnostics, food control and environmental monitoring. Recently, spintronic-devices have emerged as a promising alternative to the existent technologies [1-3]. A number of advantages, namely high sensitivity, easy integration, miniaturization, scalability, robustness and low cost make these devices potentially capable of responding to the existent technological need. In parallel, the field of microfluidics has shown great advances . Microfluidic systems allow the analysis of small sample volumes (from micro- down to pico-liters), often by automate sample processing with the ability to integrate several steps into a single device (analyte amplification, concentration, separation and/or labeling), all in a reduced assay time (minutes to hours) and affordable cost. The merging of these two technologies, magnetoresistive biochips and microfluidics, will enable the development of highly competitive devices. This work reports the integration of a magnetoresistive biochip with a microfluidic system inside a portable and autonomous electronic platform aiming for a fully integrated device. A microfluidic structure fabricated in polydimethylsiloxane with dimensions of W: 0.5mm, H: 0.1mm, L: 10mm, associated to a mechanical system to align and seal the channel by pressure is presented (Fig. 1) . The goal is to perform sample loading and transportation over the chip and simultaneously control the stringency and uniformity of the wash-out process. The biochip output is acquired by an electronic microsystem incorporating the circuitry to control, address and read-out the 30 spin-valve sensors sequentially (Fig. 1) . This platform is being applied to the detection of water-borne microbial pathogens (e.g. Salmonella and Escherichia coli) and genetic diseases diagnosis (e.g. cystic fibrosis) through DNA hybridization assays. Open chamber measurements were
Aeinehvand, Mohammad Mahdi; Ibrahim, Fatimah; Harun, Sulaiman Wadi; Kazemzadeh, Amin; Rothan, Hussin A; Yusof, Rohana; Madou, Marc
Centrifugal microfluidic systems utilize a conventional spindle motor to automate parallel biochemical assays on a single microfluidic disk. The integration of complex, sequential microfluidic procedures on these platforms relies on robust valving techniques that allow for the precise control and manipulation of fluid flow. The ability of valves to consistently return to their former conditions after each actuation plays a significant role in the real-time manipulation of fluidic operations. In this paper, we introduce an active valving technique that operates based on the deflection of a latex film with the potential for real-time flow manipulation in a wide range of operational spinning speeds. The reversible thermo-pneumatic valve (RTPV) seals or reopens an inlet when a trapped air volume is heated or cooled, respectively. The RTPV is a gas-impermeable valve composed of an air chamber enclosed by a latex membrane and a specially designed liquid transition chamber that enables the efficient usage of the applied thermal energy. Inputting thermo-pneumatic (TP) energy into the air chamber deflects the membrane into the liquid transition chamber against an inlet, sealing it and thus preventing fluid flow. From this point, a centrifugal pressure higher than the induced TP pressure in the air chamber reopens the fluid pathway. The behaviour of this newly introduced reversible valving system on a microfluidic disk is studied experimentally and theoretically over a range of rotational frequencies from 700 RPM to 2500 RPM. Furthermore, adding a physical component (e.g., a hemispherical rubber element) to induce initial flow resistance shifts the operational range of rotational frequencies of the RTPV to more than 6000 RPM. An analytical solution for the cooling of a heated RTPV on a spinning disk is also presented, which highlights the need for the future development of time-programmable RTPVs. Moreover, the reversibility and gas impermeability of the RTPV in the
Mark, D.; Haeberle, S.; Roth, G.; von Stetten, F.; Zengerle, R.
This review summarizes recent developments in microfluidic platform approaches. In contrast to isolated application-specific solutions, a microfluidic platform provides a set of fluidic unit operations, which are designed for easy combination within a well-defined fabrication technology. This allows the implementation of different application-specific (bio-) chemical processes, automated by microfluidic process integration . A brief introduction into technical advances, major market segments and promising applications is followed by a detailed characterization of different microfluidic platforms, comprising a short definition, the functional principle, microfluidic unit operations, application examples as well as strengths and limitations. The microfluidic platforms in focus are lateral flow tests, linear actuated devices, pressure driven laminar flow, microfluidic large scale integration, segmented flow microfluidics, centrifugal microfluidics, electro-kinetics, electrowetting, surface acoustic waves, and systems for massively parallel analysis. The review concludes with the attempt to provide a selection scheme for microfluidic platforms which is based on their characteristics according to key requirements of different applications and market segments. Applied selection criteria comprise portability, costs of instrument and disposable, sample throughput, number of parameters per sample, reagent consumption, precision, diversity of microfluidic unit operations and the flexibility in programming different liquid handling protocols.
Fernandes, Ana C.; Semenova, Daria; Panjan, Peter
The limited availability of metabolite-specific sensors for continuous sampling and monitoring is one of the main bottlenecks contributing to failures in bioprocess development. Furthermore, only a limited number of approaches exist to connect currently available measurement systems with high...... throughput reactor units. This is especially relevant in the biocatalyst screening and characterization stage of process development. In this work, a strategy for sensor integration in microfluidic platforms is demonstrated, to address the need for rapid, cost-effective and high-throughput screening...... of the sample solution up to 10 times. In order to highlight the features of the proposed platform, inline monitoring of glucose levels is presented and discussed. Glucose was chosen due to its importance in biotechnology as a relevant substrate. The platform demonstrated continuous measurement of substrate...
Fernandes, Ana C; Semenova, Daria; Panjan, Peter; Sesay, Adama M; Gernaey, Krist V; Krühne, Ulrich
The limited availability of metabolite-specific sensors for continuous sampling and monitoring is one of the main bottlenecks contributing to failures in bioprocess development. Furthermore, only a limited number of approaches exist to connect currently available measurement systems with high throughput reactor units. This is especially relevant in the biocatalyst screening and characterization stage of process development. In this work, a strategy for sensor integration in microfluidic platforms is demonstrated, to address the need for rapid, cost-effective and high-throughput screening in bioprocesses. This platform is compatible with different sensor formats by enabling their replacement and was built in order to be highly flexible and thus suitable for a wide range of applications. Moreover, this re-usable platform can easily be connected to analytical equipment, such as HPLC, laboratory scale reactors or other microfluidic chips through the use of standardized fittings. In addition, the developed platform includes a two-sensor system interspersed with a mixing channel, which allows the detection of samples that might be outside the first sensor's range of detection, through dilution of the sample solution up to 10 times. In order to highlight the features of the proposed platform, inline monitoring of glucose levels is presented and discussed. Glucose was chosen due to its importance in biotechnology as a relevant substrate. The platform demonstrated continuous measurement of substrate solutions for up to 12 h. Furthermore, the influence of the fluid velocity on substrate diffusion was observed, indicating the need for in-flow calibration to achieve a good quantitative output. Copyright © 2018 Elsevier B.V. All rights reserved.
Kittelmann, Jörg; Radtke, Carsten P.; Waldbaur, Ansgar; Neumann, Christiane; Hubbuch, Jürgen; Rapp, Bastian E.
Since the early days microfluidics as a scientific discipline has been an interdisciplinary research field with a wide scope of potential applications. Besides tailored assays for point-of-care (PoC) diagnostics, microfluidics has been an important tool for large-scale screening of reagents and building blocks in organic chemistry, pharmaceutics and medical engineering. Furthermore, numerous potential marketable products have been described over the years. However, especially in industrial applications, microfluidics is often considered only an alternative technology for fluid handling, a field which is industrially mostly dominated by large-scale numerically controlled fluid and liquid handling stations. Numerous noteworthy products have dominated this field in the last decade and have been inhibited the widespread application of microfluidics technology. However, automated liquid handling stations and microfluidics do not have to be considered as mutually exclusive approached. We have recently introduced a hybrid fluidic platform combining an industrially established liquid handling station and a generic microfluidic interfacing module that allows probing a microfluidic system (such as an essay or a synthesis array) using the instrumentation provided by the liquid handling station. We term this technology "Microfluidic on Liquid Handling Stations (μF-on-LHS)" - a classical "best of both worlds"- approach that allows combining the highly evolved, automated and industry-proven LHS systems with any type of microfluidic assay. In this paper we show, to the best of our knowledge, the first droplet microfluidics application on an industrial LHS using the μF-on-LHS concept.
Fractal capacitive electrodes have been successfully integrated into a digital microfluidic open-platform. These electrodes perform actuation and withstand voltages up to 300V without insulation-layer breakdown. They were used to quantify the concentration levels of C-reactive protein (CRP) to determine the risk of cardiovascular disease. The capacitance increased sevenfold and stabilized in less than 5 minutes. The sensor shows a decreasing trend of capacitance readouts with the increase of concentrations. The same immunoassay was tested with untreated electrodes and showed no significant response, which suggests that immobilization was necessary. This configuration allows the electrodes to be used as biosensors.
droplet-based microfluidic technology to generate population ‘bottleneck’. This platform will serve as a critical foundation for our long-term goal to...Final Report: Development of a Microfluidic Platform to Analyze Evolution of Programmed Bacterial Death The views, opinions and/or findings contained...Triangle Park, NC 27709-2211 Microfluidics , systems biology REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 10. SPONSOR/MONITOR’S ACRONYM
Han, Hao-Wei; Hsu, Shan-Hui
The controversial roles of mesenchymal stem cells (MSCs) in lung cancer development are not yet resolved because of the lack of an extracellular environment that mimics the tumor microenvironment. Three-dimensional (3D) culture system is an emerging research tool for biomedical applications such as drug screening. In this study, MSCs and human non-small cell lung carcinoma cells (A549) were co-cultured on a thin biomaterial-based substratum (hyaluronan-grafted chitosan, CS-HA; ∼2μm), and they were self-organized into the 3D tumor co-spheroids with core-shell structure. The gene expression levels of tumorigenicity markers in cancer cells associated with cancer stemness, epithelial-mesenchymal transition (EMT) property, and cell mobility were up-regulated for more than twofold in the MSC-tumor co-spheroids, through the promoted expression of certain tumor enhancers and the direct cell-cell interaction. To verify the different extents of tumorigenicity, A549 cells or those co-cultured with MSCs were transplanted into zebrafish embryos for evaluation in vivo. The tumorigenicity obtained from the zebrafish xenotransplantation model was consistent with that observed in vitro. These evidences suggest that the CS-HA substrate-based 3D co-culture platform for cancer cells and MSCs may be a convenient tool for studying the cell-cell interaction in a tumor-like microenvironment and potentially for cancer drug testing. Mesenchymal stem cells (MSCs) have been found in several types of tumor tissues. However, the controversial roles of MSCs in cancer development are still unsolved. Chitosan and hyaluronan are commonly used materials in the biomedical field. In the current study, we co-cultured lung cancer cells and MSCs on the planar hyaluronan-grafted chitosan (CS-HA) hybrid substrates, and discovered that lung cancer cells and MSCs were rapidly self-assembled into 3D tumor spheroids with core-shell structure on the substrates after only two days in culture. Therefore, CS
Gerard , Charline ,; Ferry , Gilles; Vuillard , Laurent ,; Boutin , Jean ,; Ferte , Nathalie ,; Grossier , Romain ,; Candoni , Nadine ,; Veesler , Stéphane ,
Here, we describe a plug-and-play microfluidic platform, suitable for protein crystallization. The droplet factory is designed to generate hundreds of droplets as small as a few nanoliters (2 to 10nL) for screening and optimization of crystallization conditions. Commercially-available microfluidic junctions and tubing are combined to create the appropriate geometry. In addition, a " chemical library " is produced in tubing. The microfluidic geometry for a " crystallization agent-based chemica...
Lan, Shih-Feng; Starly, Binil
Prediction of human response to potential therapeutic drugs is through conventional methods of in vitro cell culture assays and expensive in vivo animal testing. Alternatives to animal testing require sophisticated in vitro model systems that must replicate in vivo like function for reliable testing applications. Advancements in biomaterials have enabled the development of three-dimensional (3D) cell encapsulated hydrogels as in vitro drug screening tissue model systems. In this study, we have developed an in vitro platform to enable high density 3D culture of liver cells combined with a monolayer growth of target breast cancer cell line (MCF-7) in a static environment as a representative example of screening drug compounds for hepatotoxicity and drug efficacy. Alginate hydrogels encapsulated with serial cell densities of HepG2 cells (10 5 -10 8 cells/ml) are supported by a porous poly-carbonate disc platform and co-cultured with MCF-7 cells within standard cell culture plates during a 3 day study period. The clearance rates of drug transformation by HepG2 cells are measured using a coumarin based pro-drug. The platform was used to test for HepG2 cytotoxicity 50% (CT 50 ) using commercially available drugs which further correlated well with published in vivo LD 50 values. The developed test platform allowed us to evaluate drug dose concentrations to predict hepatotoxicity and its effect on the target cells. The in vitro 3D co-culture platform provides a scalable and flexible approach to test multiple-cell types in a hybrid setting within standard cell culture plates which may open up novel 3D in vitro culture techniques to screen new chemical entity compounds. - Graphical abstract: Display Omitted Highlights: → A porous support disc design to support the culture of desired cells in 3D hydrogels. → Demonstrated the co-culture of two cell types within standard cell-culture plates. → A scalable, low cost approach to toxicity screening involving multiple cell
Full Text Available Microfluidic systems enable precise control over tiny volumes of fluid in a compact and low-cost form, thus providing the ideal platform on which to develop point-of-care diagnostic solutions. Centrifugal microfluidic systems, also referred...
Ahmad Rezaei Kolahchi
Full Text Available Development of predictive multi-organ models before implementing costly clinical trials is central for screening the toxicity, efficacy, and side effects of new therapeutic agents. Despite significant efforts that have been recently made to develop biomimetic in vitro tissue models, the clinical application of such platforms is still far from reality. Recent advances in physiologically-based pharmacokinetic and pharmacodynamic (PBPK-PD modeling, micro- and nanotechnology, and in silico modeling have enabled single- and multi-organ platforms for investigation of new chemical agents and tissue-tissue interactions. This review provides an overview of the principles of designing microfluidic-based organ-on-chip models for drug testing and highlights current state-of-the-art in developing predictive multi-organ models for studying the cross-talk of interconnected organs. We further discuss the challenges associated with establishing a predictive body-on-chip (BOC model such as the scaling, cell types, the common medium, and principles of the study design for characterizing the interaction of drugs with multiple targets.
The digital microfluidic (DMF) platform introduces many applications in biomedical assays. If it is to be commercially available to the public, it needs to have the essential features of smart sensing and a compact size. In this work, we report on a fractal electrode biosensor that is used for both droplet actuation and sensing C-reactive protein (CRP) concentration levels to assess cardiac disease risk. Our proposed electrode is the first two-terminal electrode design to be integrated into DMF platforms. A simulation of the electrical field distribution shows reduced peak intensities and uniform distribution of the field. When compared to a V-notch square electrode, the fractal electrode shows a superior performance in both aspects, i.e. field uniformity and intensity. These improvements are translated into a successful and responsive actuation of a water droplet with 100V. Likewise, the effective dielectric strength is improved by a 33% increase in the fractal electrode breakdown voltage. Additionally, the capability of the fractal electrode to work as a capacitive biosensor is evaluated with CRP quantification test. Selected fractal electrodes undergo a surface treatment to immobilize anti-CRP antibodies on their surface. The measurement shows a response to the added CRP in capacitance within three minutes. When the untreated electrodes were used for quantification, there was no significant change in capacitance, and this suggested that immobilization was necessary. The electrodes configuration in the fabricated DMF platform allows the fractal electrodes to be selectively used as biosensors, which means the device could be integrated into point-of-care applications.
Full Text Available Microfluidic systems enable precise control over tiny volumes of fluid in a compact and low-cost form, thus providing the ideal platform on which to develop point-of-care diagnostic solutions. Centrifugal microfluidic systems, also referred to as lab-on-a-disc or lab-on-a-CD systems, provide a particularly attractive solution for the implementation of microfluidic point-of-care diagnostic solutions as a result of their simple and compact instrumentation, as well as their functional diversity. Here we detail the implementation of a centrifugal microfluidic platform the first of its kind in South Africa as a foundation for the development of point-of-care diagnostic applications for which both the need and impact is great. The centrifugal microfluidic platform consists of three main components: a microfluidic disc device similar in size and shape to a CD, a system for controlling fluid flow on the device, and a system for recording the results obtained. These components have been successfully implemented and tested. Preliminary test results show that microfluidic functions such as pumping and valving of fluids can be successfully achieved, as well as the generation of monodisperse microfluidic droplets, providing a complete centrifugal microfluidic platform and the building blocks on which to develop a variety of applications, including point-of-care diagnostics. The lab-on-a-disc platform has the potential to provide new diagnostic solutions at the point-of-need in health- and industry-related areas. This paves the way for providing resource limited areas with services such as improved, decentralised health-care access or water-quality monitoring, and reduced diagnosis times at a low cost.
Sanjay, Sharma T; Fu, Guanglei; Dou, Maowei; Xu, Feng; Liu, Rutao; Qi, Hao; Li, XiuJun
Early and timely detection of disease biomarkers can prevent the spread of infectious diseases, and drastically decrease the death rate of people suffering from different diseases such as cancer and infectious diseases. Because conventional diagnostic methods have limited application in low-resource settings due to the use of bulky and expensive instrumentation, simple and low-cost point-of-care diagnostic devices for timely and early biomarker diagnosis is the need of the hour, especially in rural areas and developing nations. The microfluidics technology possesses remarkable features for simple, low-cost, and rapid disease diagnosis. There have been significant advances in the development of microfluidic platforms for biomarker detection of diseases. This article reviews recent advances in biomarker detection using cost-effective microfluidic devices for disease diagnosis, with the emphasis on infectious disease and cancer diagnosis in low-resource settings. This review first introduces different microfluidic platforms (e.g. polymer and paper-based microfluidics) used for disease diagnosis, with a brief description of their common fabrication techniques. Then, it highlights various detection strategies for disease biomarker detection using microfluidic platforms, including colorimetric, fluorescence, chemiluminescence, electrochemiluminescence (ECL), and electrochemical detection. Finally, it discusses the current limitations of microfluidic devices for disease biomarker detection and future prospects.
Full Text Available Microfluidic platforms have received much attention in recent years. In particular, there is interest in combining spectroscopy with microfluidic platforms. This work investigates the integration of microfluidic platforms and terahertz time-domain spectroscopy (THz-TDS systems. A semiclassical computational model is used to simulate the emission of THz radiation from a GaAs photoconductive THz emitter. This model incorporates white noise with increasing noise amplitude (corresponding to decreasing dynamic range values. White noise is selected over other noise due to its contributions in THz-TDS systems. The results from this semiclassical computational model, in combination with defined sample thicknesses, can provide the maximum measurable absorption coefficient for a microfluidic-based THz-TDS system. The maximum measurable frequencies for such systems can be extracted through the relationship between the maximum measurable absorption coefficient and the absorption coefficient for representative biofluids. The sample thickness of the microfluidic platform and the dynamic range of the THz-TDS system play a role in defining the maximum measurable frequency for microfluidic-based THz-TDS systems. The results of this work serve as a design tool for the development of such systems.
Strohmeier, O; Keller, M; Schwemmer, F; Zehnle, S; Mark, D; von Stetten, F; Zengerle, R; Paust, N
Centrifugal microfluidics has evolved into a mature technology. Several major diagnostic companies either have products on the market or are currently evaluating centrifugal microfluidics for product development. The fields of application are widespread and include clinical chemistry, immunodiagnostics and protein analysis, cell handling, molecular diagnostics, as well as food, water, and soil analysis. Nevertheless, new fluidic functions and applications that expand the possibilities of centrifugal microfluidics are being introduced at a high pace. In this review, we first present an up-to-date comprehensive overview of centrifugal microfluidic unit operations. Then, we introduce the term "process chain" to review how these unit operations can be combined for the automation of laboratory workflows. Such aggregation of basic functionalities enables efficient fluidic design at a higher level of integration. Furthermore, we analyze how novel, ground-breaking unit operations may foster the integration of more complex applications. Among these are the storage of pneumatic energy to realize complex switching sequences or to pump liquids radially inward, as well as the complete pre-storage and release of reagents. In this context, centrifugal microfluidics provides major advantages over other microfluidic actuation principles: the pulse-free inertial liquid propulsion provided by centrifugal microfluidics allows for closed fluidic systems that are free of any interfaces to external pumps. Processed volumes are easily scalable from nanoliters to milliliters. Volume forces can be adjusted by rotation and thus, even for very small volumes, surface forces may easily be overcome in the centrifugal gravity field which enables the efficient separation of nanoliter volumes from channels, chambers or sensor matrixes as well as the removal of any disturbing bubbles. In summary, centrifugal microfluidics takes advantage of a comprehensive set of fluidic unit operations such as
Hlawatsch, Nadine; Bangert, Michael; Miethe, Peter; Becker, Holger; Gärtner, Claudia
Point-of-care diagnostics (POC) is one of the key application fields for lab-on-a-chip devices. While in recent years much of the work has concentrated on integrating complex molecular diagnostic assays onto a microfluidic device, there is a need to also put comparatively simple immunoassay-type protocols on a microfluidic platform. In this paper, we present the development of a microfluidic cartridge using an immunofiltration approach. In this method, the sandwich immunoassay takes place in a porous frit on which the antibodies have immobilized. The device is designed to be able to handle three samples in parallel and up to four analytical targets per sample. In order to meet the critical cost targets for the diagnostic market, the microfluidic chip has been designed and manufactured using high-volume manufacturing technologies in mind. Validation experiments show comparable sensitivities in comparison with conventional immunofiltration kits.
Bruchet, Anthony; Mariet, Clarisse; Taniga, Velan; Descroix, Stephanie; Malaquin, Laurent; Goutelard, Florence
The use of a centrifugal micro-fluidic platform is for the first time reported as an alternative to classical chromatographic procedures for radiochemistry. The original design of the micro-fluidic platform has been thought to fasten and simplify the prototyping process with the use of a circular platform integrating four rectangular microchips made of thermoplastic. The microchips, dedicated to anion-exchange chromatographic separations, integrate a localized monolithic stationary phase as well as injection and collection reservoirs. The results presented here were obtained with a simplified simulated nuclear spent fuel sample composed of non-radioactive isotopes of Europium and Uranium, in proportion usually found for uranium oxide nuclear spent fuel. While keeping the analytical results consistent with the conventional procedure (extraction yield for Europium of ∼97%), the use of the centrifugal micro-fluidic platform allowed to reduce the volume of liquid needed by a factor of ∼250. Thanks to their unique 'easy-to-use' features, centrifugal micro-fluidic platforms are potential successful candidates for the down-scaling of chromatographic separation of radioactive samples (automation, multiplexing, easy integration in glove-boxes environment and low cost of maintenance). (authors)
Full Text Available The desideratum to develop a fully integrated Lab-on-a-chip device capable ofrapid specimen detection for high throughput in-situ biomedical diagnoses and Point-of-Care testing applications has called for the integration of some of the novel technologiessuch as the microfluidics, microphotonics, immunoproteomics and Micro ElectroMechanical Systems (MEMS. In the present work, a silicon based microfluidic device hasbeen developed for carrying out fluorescence based immunoassay. By hybrid attachment ofthe microfluidic device with a Spectrometer-on-chip, the feasibility of synthesizing anintegrated Lab-on-a-chip type device for fluorescence based biosensing has beendemonstrated. Biodetection using the microfluidic device has been carried out usingantigen sheep IgG and Alexafluor-647 tagged antibody particles and the experimentalresults prove that silicon is a compatible material for the present application given thevarious advantages it offers such as cost-effectiveness, ease of bulk microfabrication,superior surface affinity to biomolecules, ease of disposability of the device etc., and is thussuitable for fabricating Lab-on-a-chip type devices.
Vedarethinam, Indumathi; Avaliani, N.; Tønnesen, J.
In this work, we present the development of a transparent poly(methyl methacrylate) (PMMA) based microfluidic culture system for handling long-term brain slice cultures independent of an incubator. The different stages of system development have been validated by culturing GFP producing brain sli...
Ghazal, Aghiad; Gontsarik, Mark; Kutter, Jörg P.
A microfluidic platform combined with synchrotron small-angle X-ray scattering (SAXS) was used for monitoring the continuous production of multilamellar vesicles (MLVs). Their production was fast and started to evolve within less than 0.43 s of contact between the lipids and the aqueous phase...
Wu, Meiye; Singh, Anup K.
The present invention relates to a microfluidic device and platform configured to conduct multiplexed analysis within the device. In particular, the device allows multiple targets to be detected on a single-cell level. Also provided are methods of performing multiplexed analyses to detect one or more target nucleic acids, proteins, and post-translational modifications.
Giri, Basant; Peesara, Ravichander R.; Yanagisawa, Naoki; Dutta, Debashis
Implementing enzyme-linked immunosorbent assays (ELISA) in microchannels offers several advantages over its traditional microtiter plate-based format, including a reduced sample volume requirement, shorter incubation period, and greater sensitivity. Moreover, microfluidic ELISA platforms are inexpensive to fabricate and allow integration of…
Nery, Flavia C.; da Hora, Cintia C.; Atai, Nadia A.; Kim, Edward Y.; Hettich, Jasmin; Mempel, Thorsten R.; Breakefield, Xandra O.; Irimia, Daniel
Microfluidic platforms for quantitative evaluation of cell biologic processes allow low cost and time efficient research studies of biological and pathological events, such as monitoring cell migration by real-time imaging. In healthy and disease states, cell migration is crucial in development and
Flores, G; Aracil, C; Perdigones, F; Quero, J M
In this paper, a single-use and unidirectional microvalve with low consumption of energy for PCB-based microfluidic platforms is reported. Its activation is easy because it works as a fuse. The fabrication process of the device is based on PCB technology and a typical SU-8 process, using the PCB as a substrate and SU-8 for the microfluidic channels and chambers. The microvalve is intended to be used to impulse small volumes of fluids and it has been designed to be highly integrable in PCB-based microfluidic platforms. The proposed device has been fabricated, integrated and tested in a general purpose microfluidic circuit, resulting in a low activation time, of about 100 μs, and a low consumption of energy, with a maximum of 27 mJ. These results show a significant improvement because the energy consumption is about 84% lower and the time response is about four orders of magnitude shorter if compared with similar microvalves for impulsion of fluids on PCB-based platforms. (paper)
Russo, Maria; Bevilacqua, Paolo; Netti, Paolo Antonio; Torino, Enza
Recent advancements in imaging diagnostics have focused on the use of nanostructures that entrap Magnetic Resonance Imaging (MRI) Contrast Agents (CAs), without the need to chemically modify the clinically approved compounds. Nevertheless, the exploitation of microfluidic platforms for their controlled and continuous production is still missing. Here, a microfluidic platform is used to synthesize crosslinked Hyaluronic Acid NanoParticles (cHANPs) in which a clinically relevant MRI-CAs, gadolinium diethylenetriamine penta-acetic acid (Gd-DTPA), is entrapped. This microfluidic process facilitates a high degree of control over particle synthesis, enabling the production of monodisperse particles as small as 35 nm. Furthermore, the interference of Gd-DTPA during polymer precipitation is overcome by finely tuning process parameters and leveraging the use of hydrophilic-lipophilic balance (HLB) of surfactants and pH conditions. For both production strategies proposed to design Gd-loaded cHANPs, a boosting of the relaxation rate T1 is observed since a T1 of 1562 is achieved with a 10 μM of Gd-loaded cHANPs while a similar value is reached with 100 μM of the relevant clinical Gd-DTPA in solution. The advanced microfluidic platform to synthesize intravascularly-injectable and completely biocompatible hydrogel nanoparticles entrapping clinically approved CAs enables the implementation of straightforward and scalable strategies in diagnostics and therapy applications.
Wade, James H; Jones, Joshua D; Lenov, Ivan L; Riordan, Colleen M; Sligar, Stephen G; Bailey, Ryan C
The characterization of integral membrane proteins presents numerous analytical challenges on account of their poor activity under non-native conditions, limited solubility in aqueous solutions, and low expression in most cell culture systems. Nanodiscs are synthetic model membrane constructs that offer many advantages for studying membrane protein function by offering a native-like phospholipid bilayer environment. The successful incorporation of membrane proteins within Nanodiscs requires experimental optimization of conditions. Standard protocols for Nanodisc formation can require large amounts of time and input material, limiting the facile screening of formation conditions. Capitalizing on the miniaturization and efficient mass transport inherent to microfluidics, we have developed a microfluidic platform for efficient Nanodisc assembly and purification, and demonstrated the ability to incorporate functional membrane proteins into the resulting Nanodiscs. In addition to working with reduced sample volumes, this platform simplifies membrane protein incorporation from a multi-stage protocol requiring several hours or days into a single platform that outputs purified Nanodiscs in less than one hour. To demonstrate the utility of this platform, we incorporated Cytochrome P450 into Nanodiscs of variable size and lipid composition, and present spectroscopic evidence for the functional active site of the membrane protein. This platform is a promising new tool for membrane protein biology and biochemistry that enables tremendous versatility for optimizing the incorporation of membrane proteins using microfluidic gradients to screen across diverse formation conditions.
Kim, Young Wook; Mosteller, Matthew P; Subramanian, Sowmya; Meyer, Mariana T; Ghodssi, Reza; Bentley, William E
Bacterial biofilms constitute in excess of 65% of clinical microbial infections, with the antibiotic treatment of biofilm infections posing a unique challenge due to their high antibiotic tolerance. Recent studies performed in our group have demonstrated that a bioelectric effect featuring low-intensity electric signals combined with antibiotics can significantly improve the efficacy of biofilm treatment. In this work, we demonstrate the bioelectric effect using sub-micron thick planar electrodes in a microfluidic device. This is critical in efforts to develop microsystems for clinical biofilm infection management, including both in vivo and in vitro applications. Adaptation of the method to the microscale, for example, can enable the development of localized biofilm infection treatment using microfabricated medical devices, while augmenting existing capabilities to perform biofilm management beyond the clinical realm. Furthermore, due to scale-down of the system, the voltage requirement for inducing the electric field is reduced further below the media electrolysis threshold. Enhanced biofilm treatment using the bioelectric effect in the developed microfluidic device elicited a 56% greater reduction in viable cell density and 26% further decrease in biomass growth compared to traditional antibiotic therapy. This biofilm treatment efficacy, demonstrated in a micro-scale device and utilizing biocompatible voltage ranges, encourages the use of this method for future clinical biofilm treatment applications. (paper)
Vergani, Marco; Carminati, Marco; Ferrari, Giorgio
An electrochemical detection system specifically designed for multi-parameter real-time monitoring of stem cell culturing/differentiation in a microfluidic system is presented. It is composed of a very compact 24-channel electronic board, compatible with arrays of microelectrodes and coupled...... to a microfluidic cell culture system. A versatile data acquisition software enables performing amperometry, cyclic voltammetry and impedance spectroscopy in each of the 12 independent chambers over a 100 kHz bandwidth with current resolution down to 5 pA for 100 ms measuring time. The design of the platform, its...... realization and experimental characterization are reported, with emphasis on the analysis of impact of input capacitance (i.e., microelectrode size) and microfluidic pump operation on current noise. Programmable sequences of successive injections of analytes (ferricyanide and dopamine) and rinsing buffer...
Due to the importance and wide applications of the DNA analysis, there is a need to make genetic analysis more available and more affordable. As such, the aim of this PhD thesis is to optimize a colorimetric DNA biosensor based on gold nanoprobes developed in CEMOP by reducing its price and the needed volume of solution without compromising the device sensitivity and reliability, towards the point of care use. Firstly, the price of the biosensor was decreased by replacing the silicon photodetector by a low cost, solution processed TiO2 photodetector. To further reduce the photodetector price, a novel fabrication method was developed: a cost-effective inkjet printing technology that enabled to increase TiO2 surface area. Secondly, the DNA biosensor was optimized by means of microfluidics that offer advantages of miniaturization, much lower sample/reagents consumption, enhanced system performance and functionality by integrating different components. In the developed microfluidic platform, the optical path length was extended by detecting along the channel and the light was transmitted by optical fibres enabling to guide the light very close to the analysed solution. Microfluidic chip of high aspect ratio ( 13), smooth and nearly vertical sidewalls was fabricated in PDMS using a SU-8 mould for patterning. The platform coupled to the gold nanoprobe assay enabled detection of Mycobacterium tuberculosis using 3 mul on DNA solution, i.e. 20 times less than in the previous state-of-the-art. Subsequently, the bio-microfluidic platform was optimized in terms of cost, electrical signal processing and sensitivity to colour variation, yielding 160% improvement of colorimetric AuNPs analysis. Planar microlenses were incorporated to converge light into the sample and then to the output fibre core increasing 6 times the signal-to-losses ratio. The optimized platform enabled detection of single nucleotide polymorphism related with obesity risk (FTO) using target DNA concentration
Cao, Weidong; Bean, Brian; Corey, Scott; Coursey, Johnathan S; Hasson, Kenton C; Inoue, Hiroshi; Isano, Taisuke; Kanderian, Sami; Lane, Ben; Liang, Hongye; Murphy, Brian; Owen, Greg; Shinoda, Nobuhiko; Zeng, Shulin; Knight, Ivor T
We report the development of an automated genetic analyzer for human sample testing based on microfluidic rapid polymerase chain reaction (PCR) with high-resolution melting analysis (HRMA). The integrated DNA microfluidic cartridge was used on a platform designed with a robotic pipettor system that works by sequentially picking up different test solutions from a 384-well plate, mixing them in the tips, and delivering mixed fluids to the DNA cartridge. A novel image feedback flow control system based on a Canon 5D Mark II digital camera was developed for controlling fluid movement through a complex microfluidic branching network without the use of valves. The same camera was used for measuring the high-resolution melt curve of DNA amplicons that were generated in the microfluidic chip. Owing to fast heating and cooling as well as sensitive temperature measurement in the microfluidic channels, the time frame for PCR and HRMA was dramatically reduced from hours to minutes. Preliminary testing results demonstrated that rapid serial PCR and HRMA are possible while still achieving high data quality that is suitable for human sample testing. © 2015 Society for Laboratory Automation and Screening.
Agudelo, C G; Sanati, A; Ghanbari, M; Packirisamy, M; Geitmann, A
Pollen tubes are an excellent model for the investigation of plant cell growth: they elongate at very high rates and are easily cultured in vitro. One major constraint in the study of pollen tube growth has been the difficulty in providing an in vitro testing environment that physically resembles the in vivo conditions. This work presents the development of a microfluidic platform for the study and manipulation of individual pollen tubes. The platform is fabricated from polydimethylsiloxane using a Silicon/SU-8 mold and makes use of microfluidics to distribute pollen grains to serially arranged microchannels into which the tubes grow to allow for individual testing. A 2D finite element fluid analysis is done to assist optimization of the architectural design. Validation of the device is carried out by growing Camellia japonica pollen. Results show that pollen tube germination and growth rate within the microfluidic network are similar to those obtained in conventional plate or batch assays. The microfluidic network allows for specific testing of a variety of structural features as demonstrated with a simple collision test, and it permits the straightforward integration of further single-cell test assays. (paper)
Huberts, Daphne H E W; Sik Lee, Sung; Gonzáles, Javier; Janssens, Georges E; Vizcarra, Ima Avalos; Heinemann, Matthias
This protocol describes the production and operation of a microfluidic dissection platform for long-term, high-resolution imaging of budding yeast cells. At the core of this platform is an array of micropads that trap yeast cells in a single focal plane. Newly formed daughter cells are subsequently washed away by a continuous flow of fresh culture medium. In a typical experiment, 50-100 cells can be tracked during their entire replicative lifespan. Apart from aging-related research, the microfluidic platform can also be a valuable tool for other studies requiring the monitoring of single cells over time. Here we provide step-by-step instructions on how to fabricate the silicon wafer mold, how to produce and operate the microfluidic device and how to analyze the obtained data. Production of the microfluidic dissection platform and setting up an aging experiment takes ~7 h.
National Aeronautics and Space Administration — HJ Science & Technology proposes a programmable, low-cost, and compact microfluidic platform capable of running automated end-to-end processes and optimization...
Fábio M. Pereira
Full Text Available This paper describes the development of a novel microfluidic platform for multifactorial analysis integrating four label-free detection methods: electrical impedance, refractometry, optical absorption and fluorescence. We present the rationale for the design and the details of the microfabrication of this multifactorial hybrid microfluidic chip. The structure of the platform consists of a three-dimensionally patterned polydimethylsiloxane top part attached to a bottom SU-8 epoxy-based negative photoresist part, where microelectrodes and optical fibers are incorporated to enable impedance and optical analysis. As a proof of concept, the chip functions have been tested and explored, enabling a diversity of applications: (i impedance-based identification of the size of micro beads, as well as counting and distinguishing of erythrocytes by their volume or membrane properties; (ii simultaneous determination of the refractive index and optical absorption properties of solutions; and (iii fluorescence-based bead counting.
Full Text Available Low cost, portable sensors can transform health care by bringing easily available diagnostic devices to low and middle income population, particularly in developing countries. Sample preparation, analyte handling and labeling are primary cost concerns for traditional lab-based diagnostic systems. Lab-on-a-chip (LoC platforms based on droplet-based microfluidics promise to integrate and automate these complex and expensive laboratory procedures onto a single chip; the cost will be further reduced if label-free biosensors could be integrated onto the LoC platforms. Here, we review some recent developments of label-free, droplet-based biosensors, compatible with “open” digital microfluidic systems. These low-cost droplet-based biosensors overcome some of the fundamental limitations of the classical sensors, enabling timely diagnosis. We identify the key challenges that must be addressed to make these sensors commercially viable and summarize a number of promising research directions.
Dorota G. Pijanowska
Full Text Available This article presents design and testing of a microfluidic platform for immunoassay. The method is based on sandwiched ELISA, whereby the primary antibody is immobilized on nitrocelluose and, subsequently, magnetic beads are used as a label to detect the analyte. The chip takes approximately 2 h and 15 min to complete the assay. A Hall Effect sensor using 0.35-μm BioMEMS TSMC technology (Taiwan Semiconductor Manufacturing Company Bio-Micro-Electro-Mechanical Systems was fabricated to sense the magnetic field from the beads. Furthermore, florescence detection and absorbance measurements from the chip demonstrate successful immunoassay on the chip. In addition, investigation also covers the Hall Effect simulations, mechanical modeling of the bead–protein complex, testing of the microfluidic platform with magnetic beads averaging 10 nm, and measurements with an inductor-based system.
Whipple, Devin Talmage
Diminishing supplies of conventional energy sources and growing concern over greenhouse gas emissions present significant challenges to supplying the world's rapidly increasing demand for energy. The electrochemical reduction of carbon dioxide has the potential to address many of these issues by providing a means of storing electricity in chemical form. Storing electrical energy as chemicals is beneficial for leveling the output of clean, but intermittent renewable energy sources such as wind and solar. Electrical energy stored as chemicals can also be used as carbon neutral fuels for portable applications allowing petroleum derived fuels in the transportation sector to be replaced by more environmentally friendly energy sources. However, to be a viable technology, the electrochemical reduction of carbon dioxide needs to have both high current densities and energetic efficiencies (Chapter 1). Although many researchers have studied the electrochemical reduction of CO2 including parameters such as catalysts, electrolytes and temperature, further investigation is needed to improve the understanding of this process and optimize the performance (Chapter 2). This dissertation reports the development and validation of a microfluidic reactor for the electrochemical reduction of CO2 (Chapter 3). The design uses a flowing liquid electrolyte instead of the typical polymer electrolyte membrane. In addition to other benefits, this flowing electrolyte gives the reactor great flexibility, allowing independent analysis of each electrode and the testing of a wide variety of conditions. In this work, the microfluidic reactor has been used in the following areas: • Comparison of different metal catalysts for the reduction of CO2 to formic acid and carbon monoxide (Chapter 4). • Investigation of the effects of the electrolyte pH on the reduction of CO2 to formic acid and carbon monoxide (Chapter 5). • Study of amine based electrolytes for lowering the overpotentials for CO2
Farzbod, Ali; Moon, Hyejin
This paper presents the demonstration of on-chip fabrication of a potassium-selective sensor array enabled by electrowetting on dielectric digital microfluidics for the first time. This demonstration proves the concept that electrochemical sensors can be seamlessly integrated with sample preparation units in a digital microfluidic platform. More significantly, the successful on-chip fabrication of a sensor array indicates that sensors become reconfigurable and have longer lifetime in a digital microfluidic platform. The on-chip fabrication of ion-selective electrodes includes electroplating Ag followed by forming AgCl layer by chemical oxidation and depositing a thin layer of desired polymer-based ion selective membrane on one of the sensor electrodes. In this study, potassium ionophores work as potassium ion channels and make the membrane selective to potassium ions. This selectiveness results in the voltage difference across the membrane layer, which is correlated with potassium ion concentration. The calibration curve of the fabricated potassium-selective electrode demonstrates the slope of 58 mV/dec for potassium concentration in KCl sample solutions and shows good agreement with the ideal Nernstian response. The proposed sensor platform is an outstanding candidate for a portable home-use for continuous monitoring of ions thanks to its advantages such as easy automation of sample preparation and detection processes, elongated sensor lifetime, minimal membrane and sample consumption, and user-definable/reconfigurable sensor array. Copyright © 2018 Elsevier B.V. All rights reserved.
Huang, Shu-Hong; Chang, Yu-Shin; Juang, Jyh-Ming Jimmy; Chang, Kai-Wei; Tsai, Mong-Hsun; Lu, Tzu-Pin; Lai, Liang-Chuan; Chuang, Eric Y; Huang, Nien-Tsu
In this study, we developed an automated microfluidic DNA microarray (AMDM) platform for point mutation detection of genetic variants in inherited arrhythmic diseases. The platform allows for automated and programmable reagent sequencing under precise conditions of hybridization flow and temperature control. It is composed of a commercial microfluidic control system, a microfluidic microarray device, and a temperature control unit. The automated and rapid hybridization process can be performed in the AMDM platform using Cy3 labeled oligonucleotide exons of SCN5A genetic DNA, which produces proteins associated with sodium channels abundant in the heart (cardiac) muscle cells. We then introduce a graphene oxide (GO)-assisted DNA microarray hybridization protocol to enable point mutation detection. In this protocol, a GO solution is added after the staining step to quench dyes bound to single-stranded DNA or non-perfectly matched DNA, which can improve point mutation specificity. As proof-of-concept we extracted the wild-type and mutant of exon 12 and exon 17 of SCN5A genetic DNA from patients with long QT syndrome or Brugada syndrome by touchdown PCR and performed a successful point mutation discrimination in the AMDM platform. Overall, the AMDM platform can greatly reduce laborious and time-consuming hybridization steps and prevent potential contamination. Furthermore, by introducing the reciprocating flow into the microchannel during the hybridization process, the total assay time can be reduced to 3 hours, which is 6 times faster than the conventional DNA microarray. Given the automatic assay operation, shorter assay time, and high point mutation discrimination, we believe that the AMDM platform has potential for low-cost, rapid and sensitive genetic testing in a simple and user-friendly manner, which may benefit gene screening in medical practice.
Samiei, Ehsan; Tabrizian, Maryam; Hoorfar, Mina
Following the development of microfluidic systems, there has been a high tendency towards developing lab-on-a-chip devices for biochemical applications. A great deal of effort has been devoted to improve and advance these devices with the goal of performing complete sets of biochemical assays on the device and possibly developing portable platforms for point of care applications. Among the different microfluidic systems used for such a purpose, digital microfluidics (DMF) shows high flexibility and capability of performing multiplex and parallel biochemical operations, and hence, has been considered as a suitable candidate for lab-on-a-chip applications. In this review, we discuss the most recent advances in the DMF platforms, and evaluate the feasibility of developing multifunctional packages for performing complete sets of processes of biochemical assays, particularly for point-of-care applications. The progress in the development of DMF systems is reviewed from eight different aspects, including device fabrication, basic fluidic operations, automation, manipulation of biological samples, advanced operations, detection, biological applications, and finally, packaging and portability of the DMF devices. Success in developing the lab-on-a-chip DMF devices will be concluded based on the advances achieved in each of these aspects.
Epps, Robert W; Felton, Kobi C; Coley, Connor W; Abolhasani, Milad
Colloidal organic/inorganic metal-halide perovskite nanocrystals have recently emerged as a potential low-cost replacement for the semiconductor materials in commercial photovoltaics and light emitting diodes. However, unlike III-V and IV-VI semiconductor nanocrystals, studies of colloidal perovskite nanocrystals have yet to develop a fundamental and comprehensive understanding of nucleation and growth kinetics. Here, we introduce a modular and automated microfluidic platform for the systematic studies of room-temperature synthesized cesium-lead halide perovskite nanocrystals. With abundant data collection across the entirety of four orders of magnitude reaction time span, we comprehensively characterize nanocrystal growth within a modular microfluidic reactor. The developed high-throughput screening platform features a custom-designed three-port flow cell with translational capability for in situ spectral characterization of the in-flow synthesized perovskite nanocrystals along a tubular microreactor with an adjustable length, ranging from 3 cm to 196 cm. The translational flow cell allows for sampling of twenty unique residence times at a single equilibrated flow rate. The developed technique requires an average total liquid consumption of 20 μL per spectra and as little as 2 μL at the time of sampling. It may continuously sample up to 30 000 unique spectra per day in both single and multi-phase flow formats. Using the developed plug-and-play microfluidic platform, we study the growth of cesium lead trihalide perovskite nanocrystals through in situ monitoring of their absorption and emission band-gaps at residence times ranging from 100 ms to 17 min. The automated microfluidic platform enables a systematic study of the effect of mixing enhancement on the quality of the synthesized nanocrystals through a direct comparison between single- and multi-phase flow systems at similar reaction time scales. The improved mixing characteristics of the multi-phase flow
Kara, A.; Mathault, J.; Reitz, A.; Boisvert, M.; Tessier, F.; Greener, J.; Miled, A.
In this project we present a microfluidic platform with in-channel micro-electrodes for in situ screening of bio/chemical samples through a lab-on-chip system. We used a novel method to incorporate electrochemical sensors array (16x20) connected to a PCB, which opens the way for imaging applications. A 200 μm height microfluidic channel was bonded to electrochemical sensors. The micro-channel contains 3 inlets used to introduce phosphate buffer saline (PBS), ferrocynide and neurotransmitters. The flow rate was controlled through automated micro-pumps. A multiplexer was used to scan electrodes and perform individual cyclic voltammograms by a custom potentiostat. The behavior of the system was linear in terms of variation of current versus concentration. It was used to detect the neurotransmitters serotonin, dopamine and glutamate.
Gokce, Sertan Kutal; Guo, Samuel X; Ghorashian, Navid; Everett, W Neil; Jarrell, Travis; Kottek, Aubri; Bovik, Alan C; Ben-Yakar, Adela
Femtosecond laser nanosurgery has been widely accepted as an axonal injury model, enabling nerve regeneration studies in the small model organism, Caenorhabditis elegans. To overcome the time limitations of manual worm handling techniques, automation and new immobilization technologies must be adopted to improve throughput in these studies. While new microfluidic immobilization techniques have been developed that promise to reduce the time required for axotomies, there is a need for automated procedures to minimize the required amount of human intervention and accelerate the axotomy processes crucial for high-throughput. Here, we report a fully automated microfluidic platform for performing laser axotomies of fluorescently tagged neurons in living Caenorhabditis elegans. The presented automation process reduces the time required to perform axotomies within individual worms to ∼17 s/worm, at least one order of magnitude faster than manual approaches. The full automation is achieved with a unique chip design and an operation sequence that is fully computer controlled and synchronized with efficient and accurate image processing algorithms. The microfluidic device includes a T-shaped architecture and three-dimensional microfluidic interconnects to serially transport, position, and immobilize worms. The image processing algorithms can identify and precisely position axons targeted for ablation. There were no statistically significant differences observed in reconnection probabilities between axotomies carried out with the automated system and those performed manually with anesthetics. The overall success rate of automated axotomies was 67.4±3.2% of the cases (236/350) at an average processing rate of 17.0±2.4 s. This fully automated platform establishes a promising methodology for prospective genome-wide screening of nerve regeneration in C. elegans in a truly high-throughput manner.
Hsu, Yu-Hsiang; Moya, Monica L.; Hughes, Christopher C.W.; Georgea, Steven C.; Lee, Abraham P.
This paper reports a polydimethylsiloxane microfluidic model system that can develop an array of nearly identical human microtissues with interconnected vascular networks. The microfluidic system design is based on an analogy with an electric circuit, applying resistive circuit concepts to design pressure dividers in serially-connected microtissue chambers. A long microchannel (550, 620 and 775 mm) creates a resistive circuit with a large hydraulic resistance. Two media reservoirs with a large cross-sectional area and of different heights are connected to the entrance and exit of the long microchannel to serve as a pressure source, and create a near constant pressure drop along the long microchannel. Microtissue chambers (0.12 μl) serve as a two-terminal resistive component with an input impedance > 50-fold larger than the long microchannel. Connecting each microtissue chamber to two different positions along the long microchannel creates a series of pressure dividers. Each microtissue chamber enables a controlled pressure drop of a segment of the microchannel without altering the hydrodynamic behaviour of the microchannel. The result is a controlled and predictable microphysiological environment within the microchamber. Interstitial flow, a mechanical cue for stimulating vasculogenesis, was verified by finite element simulation and experiments. The simplicity of this design enabled the development of multiple microtissue arrays (5, 12, and 30 microtissues) by co-culturing endothelial cells, stromal cells, and fibrin within the microchambers over two and three week periods. This methodology enables the culturing of a large array of microtissues with interconnected vascular networks for biological studies and applications such as drug development. PMID:23723013
Coley, Connor W; Abolhasani, Milad; Lin, Hongkun; Jensen, Klavs F
We present an automated microfluidic platform for in-flow studies of visible-light photoredox catalysis in liquid or gas-liquid reactions at the 15 μL scale. An oscillatory flow strategy enables a flexible residence time while preserving the mixing and heat transfer advantages of flow systems. The adjustable photon flux made possible with the platform is characterized using actinometry. Case studies of oxidative hydroxylation of phenylboronic acids and dimerization of thiophenol demonstrate the capabilities and advantages of the system. Reaction conditions identified through droplet screening translate directly to continuous synthesis with minor platform modifications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Thaitrong, Numrin; Kim, Hanyoup; Renzi, Ronald F; Bartsch, Michael S; Meagher, Robert J; Patel, Kamlesh D
We have developed an automated quality control (QC) platform for next-generation sequencing (NGS) library characterization by integrating a droplet-based digital microfluidic (DMF) system with a capillary-based reagent delivery unit and a quantitative CE module. Using an in-plane capillary-DMF interface, a prepared sample droplet was actuated into position between the ground electrode and the inlet of the separation capillary to complete the circuit for an electrokinetic injection. Using a DNA ladder as an internal standard, the CE module with a compact LIF detector was capable of detecting dsDNA in the range of 5-100 pg/μL, suitable for the amount of DNA required by the Illumina Genome Analyzer sequencing platform. This DMF-CE platform consumes tenfold less sample volume than the current Agilent BioAnalyzer QC technique, preserving precious sample while providing necessary sensitivity and accuracy for optimal sequencing performance. The ability of this microfluidic system to validate NGS library preparation was demonstrated by examining the effects of limited-cycle PCR amplification on the size distribution and the yield of Illumina-compatible libraries, demonstrating that as few as ten cycles of PCR bias the size distribution of the library toward undesirable larger fragments. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Full Text Available Infection with Helicobacter pylori (H. pylori occurs in 50% of the world population, and is associated with the development of ulcer and gastric cancer. Serological diagnostic tests indicate an H. pylori infection by detecting antibodies directed against H. pylori proteins. In addition to line blots, multiplex assay platforms provide smart solutions for the simultaneous analysis of antibody responses towards several H. pylori proteins. We used seven H. pylori proteins (FliD, gGT, GroEL, HpaA, CagA, VacA, and HP0231 and an H. pylori lysate for the development of a multiplex serological assay on a novel microfluidic platform. The reaction limited binding regime in the microfluidic channels allows for a short incubation time of 35 min. The developed assay showed very high sensitivity (99% and specificity (100%. Besides sensitivity and specificity, the technical validation (intra-assay CV = 3.7 ± 1.2% and inter-assay CV = 5.5 ± 1.2% demonstrates that our assay is also a robust tool for the analysis of the H. pylori-specific antibody response. The integration of the virulence factors CagA and VacA allow for the assessment of the risk for gastric cancer development. The short assay time and the performance of the platform shows the potential for implementation of such assays in a clinical setting.
Carl A. Batt
Full Text Available The advent of nucleic acid-based pathogen detection methods offers increased sensitivity and specificity over traditional microbiological techniques, driving the development of portable, integrated biosensors. The miniaturization and automation of integrated detection systems presents a significant advantage for rapid, portable field-based testing. In this review, we highlight current developments and directions in nucleic acid-based micro total analysis systems for the detection of bacterial pathogens. Recent progress in the miniaturization of microfluidic processing steps for cell capture, DNA extraction and purification, polymerase chain reaction, and product detection are detailed. Discussions include strategies and challenges for implementation of an integrated portable platform.
Szydzik, C; Gavela, A F; Herranz, S; Roccisano, J; Knoerzer, M; Thurgood, P; Khoshmanesh, K; Mitchell, A; Lechuga, L M
A primary limitation preventing practical implementation of photonic biosensors within point-of-care platforms is their integration with fluidic automation subsystems. For most diagnostic applications, photonic biosensors require complex fluid handling protocols; this is especially prominent in the case of competitive immunoassays, commonly used for detection of low-concentration, low-molecular weight biomarkers. For this reason, complex automated microfluidic systems are needed to realise the full point-of-care potential of photonic biosensors. To fulfil this requirement, we propose an on-chip valve-based microfluidic automation module, capable of automating such complex fluid handling. This module is realised through application of a PDMS injection moulding fabrication technique, recently described in our previous work, which enables practical fabrication of normally closed pneumatically actuated elastomeric valves. In this work, these valves are configured to achieve multiplexed reagent addressing for an on-chip diaphragm pump, providing the sample and reagent processing capabilities required for automation of cyclic competitive immunoassays. Application of this technique simplifies fabrication and introduces the potential for mass production, bringing point-of-care integration of complex automated microfluidics into the realm of practicality. This module is integrated with a highly sensitive, label-free bimodal waveguide photonic biosensor, and is demonstrated in the context of a proof-of-concept biosensing assay, detecting the low-molecular weight antibiotic tetracycline.
Kise, Drew P; Reddish, Michael J; Brian Dyer, R
We report on a microfluidic mixer fabrication platform that increases the versatility and flexibility of mixers for biomolecular applications. A sandwich-format design allows the application of multiple spectroscopic probes to the same mixer. A polymer spacer is ‘sandwiched’ between two transparent windows, creating a closed microfluidic system. The channels of the mixer are defined by regions in the polymer spacer that lack material and therefore the polymer need not be transparent in the spectral region of interest. Suitable window materials such as CaF 2 make the device accessible to a wide range of optical probe wavelengths, from the deep UV to the mid-IR. In this study, we use a commercially available 3D printer to print the polymer spacers to apply three different channel designs into the passive, continuous-flow mixer, and integrated them with three different spectroscopic probes. All three spectroscopic probes are applicable to each mixer without further changes. The sandwich-format mixer coupled with cost-effective 3D printed fabrication techniques could increase the applicability and accessibility of microfluidic mixing to intricate kinetic schemes and monitoring chemical synthesis in cases where only one probe technique proves insufficient. (paper)
Huang, Shih-Hsuan; Hung, Lien-Yu; Lee, Gwo-Bin
The extraction of a cell's nucleus is an essential technique required for a number of procedures, such as disease diagnosis, genetic replication, and animal cloning. However, existing nucleus extraction techniques are relatively inefficient and labor-intensive. Therefore, this study presents an innovative, microfluidics-based approach featuring optically-induced cell lysis (OICL) for nucleus extraction and collection in an automatic format. In comparison to previous micro-devices designed for nucleus extraction, the new OICL device designed herein is superior in terms of flexibility, selectivity, and efficiency. To facilitate this OICL module for continuous nucleus extraction, we further integrated an optically-induced dielectrophoresis (ODEP) module with the OICL device within the microfluidic chip. This on-chip integration circumvents the need for highly trained personnel and expensive, cumbersome equipment. Specifically, this microfluidic system automates four steps by 1) automatically focusing and transporting cells, 2) releasing the nuclei on the OICL module, 3) isolating the nuclei on the ODEP module, and 4) collecting the nuclei in the outlet chamber. The efficiency of cell membrane lysis and the ODEP nucleus separation was measured to be 78.04 ± 5.70% and 80.90 ± 5.98%, respectively, leading to an overall nucleus extraction efficiency of 58.21 ± 2.21%. These results demonstrate that this microfluidics-based system can successfully perform nucleus extraction, and the integrated platform is therefore promising in cell fusion technology with the goal of achieving genetic replication, or even animal cloning, in the near future.
Geng, Tao; Smallwood, Chuck R.; Bredeweg, Erin L.; Pomraning, Kyle R.; Plymale, Andrew E.; Baker, Scott E.; Evans, James E.; Kelly, Ryan T.
Modern live-cell imaging approaches permit real-time visualization of biological processes, yet limitations exist for unicellular organism isolation, culturing and long-term imaging that preclude fully understanding how cells sense and respond to environmental perturbations and the link between single-cell variability and whole-population dynamics. Here we present a microfluidic platform that provides fine control over the local environment with the capacity to replace media components at any experimental time point, and provides both perfused and compartmentalized cultivation conditions depending on the valve configuration. The functionality and flexibility of the platform were validated using both bacteria and yeast having different sizes, motility and growth media. The demonstrated ability to track the growth and dynamics of both motile and non-motile prokaryotic and eukaryotic organisms emphasizes the versatility of the devices, which with further scale-up should enable studies in bioenergy and environmental research.
Geng, Tao; Smallwood, Chuck R; Bredeweg, Erin L; Pomraning, Kyle R; Plymale, Andrew E; Baker, Scott E; Evans, James E; Kelly, Ryan T
Modern live-cell imaging approaches permit real-time visualization of biological processes, yet limitations exist for unicellular organism isolation, culturing, and long-term imaging that preclude fully understanding how cells sense and respond to environmental perturbations and the link between single-cell variability and whole-population dynamics. Here, we present a microfluidic platform that provides fine control over the local environment with the capacity to replace media components at any experimental time point, and provides both perfused and compartmentalized cultivation conditions depending on the valve configuration. The functionality and flexibility of the platform were validated using both bacteria and yeast having different sizes, motility, and growth media. The demonstrated ability to track the growth and dynamics of both motile and non-motile prokaryotic and eukaryotic organisms emphasizes the versatility of the devices, which should enable studies in bioenergy and environmental research.
Tam, Johnny; Cordier, Guillaume Alan; Bálint, Štefan; Sandoval Álvarez, Ángel; Borbely, Joseph Steven; Lakadamyali, Melike
Recently, super-resolution microscopy methods such as stochastic optical reconstruction microscopy (STORM) have enabled visualization of subcellular structures below the optical resolution limit. Due to the poor temporal resolution, however, these methods have mostly been used to image fixed cells or dynamic processes that evolve on slow time-scales. In particular, fast dynamic processes and their relationship to the underlying ultrastructure or nanoscale protein organization cannot be discerned. To overcome this limitation, we have recently developed a correlative and sequential imaging method that combines live-cell and super-resolution microscopy. This approach adds dynamic background to ultrastructural images providing a new dimension to the interpretation of super-resolution data. However, currently, it suffers from the need to carry out tedious steps of sample preparation manually. To alleviate this problem, we implemented a simple and versatile microfluidic platform that streamlines the sample preparation steps in between live-cell and super-resolution imaging. The platform is based on a microfluidic chip with parallel, miniaturized imaging chambers and an automated fluid-injection device, which delivers a precise amount of a specified reagent to the selected imaging chamber at a specific time within the experiment. We demonstrate that this system can be used for live-cell imaging, automated fixation, and immunostaining of adherent mammalian cells in situ followed by STORM imaging. We further demonstrate an application by correlating mitochondrial dynamics, morphology, and nanoscale mitochondrial protein distribution in live and super-resolution images. PMID:25545548
Shang, Yuqin; Zeng, Yun; Zeng, Yong
Protein glycosylation is one of the key processes that play essential roles in biological functions and dysfunctions. However, progress in glycomics has considerably lagged behind genomics and proteomics, due in part to the enormous challenges in analysis of glycans. Here we present a new integrated and automated microfluidic lectin barcode platform to substantially improve the performance of lectin array for focused glycomic profiling. The chip design and flow control were optimized to promote the lectin-glycan binding kinetics and speed of lectin microarray. Moreover, we established an on-chip lectin assay which employs a very simple blocking method to effectively suppress the undesired background due to lectin binding of antibodies. Using this technology, we demonstrated focused differential profiling of tissue-specific glycosylation changes of a biomarker, CA125 protein purified from ovarian cancer cell line and different tissues from ovarian cancer patients in a fast, reproducible, and high-throughput fashion. Highly sensitive CA125 detection was also demonstrated with a detection limit much lower than the clinical cutoff value for cancer diagnosis. This microfluidic platform holds the potential to integrate with sample preparation functions to construct a fully integrated “sample-to-answer” microsystem for focused differential glycomic analysis. Thus, our technology should present a powerful tool in support of rapid advance in glycobiology and glyco-biomarker development.
Nucleic acid-based molecular diagnostics offers enormous potential for the rapid and accurate diagnosis of infectious diseases. However, most of the existing commercial tests are time-consuming and technically complicated, and are thus incompatible with the need for rapid identification of infectious agents. We have successfully developed a CD-based microfluidic platform for fast and automated DNA array hybridization and a low cost, disposable plastic microfluidic platform for polymerase chain reaction (PCR). These platforms have proved to be a promising approach to meet the requirements in terms of detection speed and operational convenience in diagnosis of infectious diseases. In the CD-based microfluidic platform for DNA hybridization, convection is introduced to the system to enhance mass transport so as to accelerate the hybridization rate since DNA hybridization is a diffusion limited reaction. Centrifugal force is utilized for sample propulsion and surface force is used for liquid gating. Standard microscope glass slides are used as the substrates for capture probes owing to their compatibility with commercially available instrumentation (e.g. laser scanners) for detection. Microfabricated polydimethylsiloxane (PDMS) structures are used to accomplish the fluidic functions required by the protocols for DNA hybridization. The assembly of the PDMS structure and the glass slide forms a flow-through hybridization unit that can be accommodated onto the CD platform for reagent manipulation. The above scheme has been validated with oligonucleotides as the targets using commercially available enzyme-labeled fluorescence (ELF 97) for detection of the hybridization events, and tested with amplicons of genomic staphylococcus DNA labeled with Cy dye. In both experiments, significantly higher fluorescence intensities were observed in the flow-through hybridization unit compared to the passive assays. The CD fluidic scheme was also adapted to the immobilization of
Full Text Available Next-generation sequencing (NGS is emerging as a powerful tool for elucidating genetic information for a wide range of applications. Unfortunately, the surging popularity of NGS has not yet been accompanied by an improvement in automated techniques for preparing formatted sequencing libraries. To address this challenge, we have developed a prototype microfluidic system for preparing sequencer-ready DNA libraries for analysis by Illumina sequencing. Our system combines droplet-based digital microfluidic (DMF sample handling with peripheral modules to create a fully-integrated, sample-in library-out platform. In this report, we use our automated system to prepare NGS libraries from samples of human and bacterial genomic DNA. E. coli libraries prepared on-device from 5 ng of total DNA yielded excellent sequence coverage over the entire bacterial genome, with >99% alignment to the reference genome, even genome coverage, and good quality scores. Furthermore, we produced a de novo assembly on a previously unsequenced multi-drug resistant Klebsiella pneumoniae strain BAA-2146 (KpnNDM. The new method described here is fast, robust, scalable, and automated. Our device for library preparation will assist in the integration of NGS technology into a wide variety of laboratories, including small research laboratories and clinical laboratories.
Kim, Hanyoup; Jebrail, Mais J; Sinha, Anupama; Bent, Zachary W; Solberg, Owen D; Williams, Kelly P; Langevin, Stanley A; Renzi, Ronald F; Van De Vreugde, James L; Meagher, Robert J; Schoeniger, Joseph S; Lane, Todd W; Branda, Steven S; Bartsch, Michael S; Patel, Kamlesh D
Next-generation sequencing (NGS) is emerging as a powerful tool for elucidating genetic information for a wide range of applications. Unfortunately, the surging popularity of NGS has not yet been accompanied by an improvement in automated techniques for preparing formatted sequencing libraries. To address this challenge, we have developed a prototype microfluidic system for preparing sequencer-ready DNA libraries for analysis by Illumina sequencing. Our system combines droplet-based digital microfluidic (DMF) sample handling with peripheral modules to create a fully-integrated, sample-in library-out platform. In this report, we use our automated system to prepare NGS libraries from samples of human and bacterial genomic DNA. E. coli libraries prepared on-device from 5 ng of total DNA yielded excellent sequence coverage over the entire bacterial genome, with >99% alignment to the reference genome, even genome coverage, and good quality scores. Furthermore, we produced a de novo assembly on a previously unsequenced multi-drug resistant Klebsiella pneumoniae strain BAA-2146 (KpnNDM). The new method described here is fast, robust, scalable, and automated. Our device for library preparation will assist in the integration of NGS technology into a wide variety of laboratories, including small research laboratories and clinical laboratories.
Full Text Available Optical fiber sensors based on waveguide technology are promising and attractive in chemical, biotechnological, agronomy, and civil engineering applications. A microfluidic system equipped with a long-period fiber grating (LPFG capable of measuring chloride ion concentrations of several sample materials is presented. The LPFG-based microfluidic platform was shown to be effective in sensing very small quantities of samples and its transmitted light signal could easily be used as a measurand. The investigated sample materials included reverse osmosis (RO water, tap water, dilute aqueous sample of sea sand soaked in RO water, aqueous sample of sea sand soaked in RO water, dilute seawater, and seawater. By employing additionally a chloride ion-selective electrode sensor for the calibration of chloride-ion concentration, a useful correlation (R2 = 0.975 was found between the separately-measured chloride concentration and the light intensity transmitted through the LPFG at a wavelength of 1,550 nm. Experimental results show that the sensitivity of the LPFG sensor by light intensity interrogation was determined to be 5.0 × 10−6 mW/mg/L for chloride ion concentrations below 2,400 mg/L. The results obtained from the analysis of data variations in time-series measurements for all sample materials show that standard deviations of output power were relatively small and found in the range of 7.413 × 10−5–2.769 × 10−3 mW. In addition, a fairly small coefficients of variations were also obtained, which were in the range of 0.03%–1.29% and decreased with the decrease of chloride ion concentrations of sample materials. Moreover, the analysis of stability performance of the LPFG sensor indicated that the random walk coefficient decreased with the increase of the chloride ion concentration, illustrating that measurement stability using the microfluidic platform was capable of measuring transmitted optical power with accuracy in the range of −0
Full Text Available We propose that a chemically agnostic approach to explore the origin of life, using an automated recursive platform based on droplet microfluidics, could be used to induce artificial chemical evolution by iterations of growth, speciation, selection, and propagation. To explore this, we set about designing an open source prototype of a fully automated evolution machine, comprising seven modules. These modules are a droplet generator, droplet transfer, passive and active size sorting, splitter, incubation chamber, reservoir, and injectors, all run together via a LabVIEWTM program integration system. Together we aim for the system to be used to drive cycles of droplet birth, selection, fusion, and propagation. As a proof of principle, in addition to the working individual modules, we present data showing the osmotic exchange of glycylglycine containing and pure aqueous droplets, showing that the fittest droplets exhibit higher osomolarity relative to their neighbours, and increase in size compared to their neighbours. This demonstrates the ability of our platform to explore some different physicochemical conditions, combining the efficiency and unbiased nature of automation with our ability to select droplets as functional units based on simple criteria.
Full Text Available A supramolecular platform based on self-assembled monolayers (SAMs has been implemented in a microfluidic device. The system has been applied for the sensing of two different analyte types: biologically relevant phosphate anions and aromatic carboxylic acids, which are important for anthrax detection. A Eu(III-EDTA complex was bound to β-cyclodextrin monolayers via orthogonal supramolecular host-guest interactions. The self-assembly of the Eu(III-EDTA conjugate and naphthalene β-diketone as an antenna resulted in the formation of a highly luminescent lanthanide complex on the microchannel surface. Detection of different phosphate anions and aromatic carboxylic acids was demonstrated by monitoring the decrease in red emission following displacement of the antenna by the analyte. Among these analytes, adenosine triphosphate (ATP and pyrophosphate, as well as dipicolinic acid (DPA which is a biomarker for anthrax, showed a strong response. Parallel fabrication of five sensing SAMs in a single multichannel chip was performed, as a first demonstration of phosphate and carboxylic acid screening in a multiplexed format that allows a general detection platform for both analyte systems in a single test run with µM and nM detection sensitivity for ATP and DPA, respectively.
Aaron P. Mosier
Full Text Available The ability to characterize the microscale mechanical properties of biological materials has the potential for great utility in the field of tissue engineering. The development and morphogenesis of mammalian tissues are known to be guided in part by mechanical stimuli received from the local environment, and tissues frequently develop to match the physical characteristics (i.e., elasticity of their environment. Quantification of these material properties at the microscale may provide valuable information to guide researchers. Presented here is a microfluidic platform for the non-destructive ex vivo microscale mechanical characterization of mammalian tissue samples by atomic force microscopy (AFM. The device was designed to physically hold a tissue sample in a dynamically controllable fluid environment while allowing access by an AFM probe operating in force spectroscopy mode to perform mechanical testing. Results of measurements performed on mouse submandibular gland samples demonstrate the ability of the analysis platform to quantify sample elasticity at the microscale, and observe chemically-induced changes in elasticity.
Full Text Available The budding yeast Saccharomyces cerevisiae divides asymmetrically, with a smaller daughter cell emerging from its larger mother cell. While the daughter lineage is immortal, mother cells age with each cell division and have a finite lifespan. The replicative ageing of the yeast mother cell has been used as a model to study the ageing of mitotically active human cells. Several microfluidic platforms, which use fluid flow to selectively remove daughter cells, have recently been developed that can monitor cell physiology as mother cells age. However, these platforms are not trivial to set up and users often require many hours of training. In this study, we have developed a simple system, which combines a commercially available microfluidic platform (the CellASIC ONIX Microfluidic Platform and a genetic tool to prevent the proliferation of daughter cells (the Mother Enrichment Program, to monitor protein abundance and localization changes during approximately the first half of the yeast replicative lifespan. We validated our system by observing known age-dependent changes, such as decreased Sir2 abundance, and have identified a protein with a previously unknown age-dependent change in localization.
Fishler, Rami; Mulligan, Molly K; Sznitman, Josué
Convective respiratory flows in the pulmonary acinus and their influence on the fate of inhaled particles are typically studied using computational fluid dynamics (CFD) or scaled-up experimental models. However, experiments that replicate several generations of the acinar tree while featuring cyclic wall motion have not yet been realized. Moreover, current experiments generally capture only flow dynamics, without inhaled particle dynamics, due to difficulties in simultaneously matching flow and particle dynamics. In an effort to overcome these limitations, we introduce a novel microfluidic device mimicking acinar flow characteristics directly at the alveolar scale. The model features an anatomically-inspired geometry that expands and contracts periodically with five dichotomously branching airway generations lined with alveolar-like cavities. We use micro-particle image velocimetry with a glycerol solution as the carrying fluid to quantitatively characterize detailed flow patterns within the device and reveal experimentally for the first time a gradual transition of alveolar flow patterns along the acinar tree from recirculating to radial streamlines, in support of hypothesized predictions from past CFD simulations. The current measurements show that our microfluidic system captures the underlying characteristics of the acinar flow environment, including Reynolds and Womersley numbers as well as cyclic wall displacements and alveolar flow patterns at a realistic length scale. With the use of air as the carrying fluid, our miniaturized platform is anticipated to capture both particle and flow dynamics and serve in the near future as a promising in vitro tool for investigating the mechanisms of particle deposition deep in the lung. © 2013 Elsevier Ltd. All rights reserved.
Christina C Marasco
Full Text Available To address the challenges of tracking the multitude of signaling molecules and metabolites that is the basis of biological complexity, we describe a strategy to expand the analytical techniques for dynamic systems biology. Using microfluidics, online desalting, and mass spectrometry technologies, we constructed and validated a platform well suited for sampling the cellular microenvironment with high temporal resolution. Our platform achieves success in: automated cellular stimulation and microenvironment control; reduced non-specific adsorption to polydimethylsiloxane due to surface passivation; real-time online sample collection; near real-time sample preparation for salt removal; and real-time online mass spectrometry. When compared against the benchmark of "in-culture" experiments combined with ultraperformance liquid chromatography-electrospray ionization-ion mobility-mass spectrometry (UPLC-ESI-IM-MS, our platform alleviates the volume challenge issues caused by dilution of autocrine and paracrine signaling and dramatically reduces sample preparation and data collection time, while reducing undesirable external influence from various manual methods of manipulating cells and media (e.g., cell centrifugation. To validate this system biologically, we focused on cellular responses of Jurkat T cells to microenvironmental stimuli. Application of these stimuli, in conjunction with the cell's metabolic processes, results in changes in consumption of nutrients and secretion of biomolecules (collectively, the exometabolome, which enable communication with other cells or tissues and elimination of waste. Naïve and experienced T-cell metabolism of cocaine is used as an exemplary system to confirm the platform's capability, highlight its potential for metabolite discovery applications, and explore immunological memory of T-cell drug exposure. Our platform proved capable of detecting metabolomic variations between naïve and experienced Jurkat T cells
Madison, Andrew C; Royal, Matthew W; Vigneault, Frederic; Chen, Liji; Griffin, Peter B; Horowitz, Mark; Church, George M; Fair, Richard B
Electrowetting-on-dielectric (EWD) digital microfluidic laboratory-on-a-chip platforms demonstrate excellent performance in automating labor-intensive protocols. When coupled with an on-chip electroporation capability, these systems hold promise for streamlining cumbersome processes such as multiplex automated genome engineering (MAGE). We integrated a single Ti:Au electroporation electrode into an otherwise standard parallel-plate EWD geometry to enable high-efficiency transformation of Escherichia coli with reporter plasmid DNA in a 200 nL droplet. Test devices exhibited robust operation with more than 10 transformation experiments performed per device without cross-contamination or failure. Despite intrinsic electric-field nonuniformity present in the EP/EWD device, the peak on-chip transformation efficiency was measured to be 8.6 ± 1.0 × 10 8 cfu·μg -1 for an average applied electric field strength of 2.25 ± 0.50 kV·mm -1 . Cell survival and transformation fractions at this electroporation pulse strength were found to be 1.5 ± 0.3 and 2.3 ± 0.1%, respectively. Our work expands the EWD toolkit to include on-chip microbial electroporation and opens the possibility of scaling advanced genome engineering methods, like MAGE, into the submicroliter regime.
Duval, Daphné; González-Guerrero, Ana Belén; Dante, Stefania; Osmond, Johann; Monge, Rosa; Fernández, Luis J; Zinoviev, Kirill E; Domínguez, Carlos; Lechuga, Laura M
One of the main limitations for achieving truly lab-on-a-chip (LOC) devices for point-of-care diagnosis is the incorporation of the "on-chip" detection. Indeed, most of the state-of-the-art LOC devices usually require complex read-out instrumentation, losing the main advantages of portability and simplicity. In this context, we present our last advances towards the achievement of a portable and label-free LOC platform with highly sensitive "on-chip" detection by using nanophotonic biosensors. Bimodal waveguide interferometers fabricated by standard silicon processes have been integrated with sub-micronic grating couplers for efficient light in-coupling, showing a phase resolution of 6.6 × 10(-4)× 2π rad and a limit of detection of 3.3 × 10(-7) refractive index unit (RIU) in bulk. A 3D network of SU-8 polymer microfluidics monolithically assembled at the wafer-level was included, ensuring perfect sealing and compact packaging. To overcome some of the drawbacks inherent to interferometric read-outs, a novel all-optical wavelength modulation system has been implemented, providing a linear response and a direct read-out of the phase variation. Sensitivity, specificity and reproducibility of the wavelength modulated BiMW sensor has been demonstrated through the label-free immunodetection of the human hormone hTSH at picomolar level using a reliable biofunctionalization process.
Zhu, Yunzeng; Chen, Yiqi; Meng, Xiangrui; Wang, Jing; Lu, Ying; Xu, Youchun; Cheng, Jing
Centrifugal microfluidics has been widely applied in the sample-in-answer-out systems for the analyses of nucleic acids, proteins, and small molecules. However, the inherent characteristic of unidirectional fluid propulsion limits the flexibility of these fluidic chips. Providing an extra degree of freedom to allow the unconstrained and reversible pumping of liquid is an effective strategy to address this limitation. In this study, a wirelessly charged centrifugal microfluidic platform with two rotation axes has been constructed and the flow control strategy in such platform with two degrees of freedom was comprehensively studied for the first time. Inductively coupled coils are installed on the platform to achieve wireless power transfer to the spinning stage. A micro servo motor is mounted on both sides of the stage to alter the orientation of the device around a secondary rotation axis on demand during stage rotation. The basic liquid operations on this platform, including directional transport of liquid, valving, metering, and mixing, are comprehensively studied and realized. Finally, a chip for the simultaneous determination of hexavalent chromium [Cr(VI)] and methanal in water samples is designed and tested based on the strategy presented in this paper, demonstrating the potential use of this platform for on-site environmental monitoring, food safety testing, and other life science applications.
Liu, Wenjia; Warden, Antony; Sun, Jiahui; Shen, Guangxia; Ding, Xianting
Portable Polymerase Chain Reaction (PCR) devices combined with microfluidic chips or lateral flow stripes have shown great potential in the field of point-of-need testing (PoNT) as they only require a small volume of patient sample and are capable of presenting results in a short time. However, the detection for multiple targets in this field leaves much to be desired. Herein, we introduce a novel PCR platform by integrating a bottom-well microfluidic chip with an infra-red (IR) excited temperature control method and fluorescence co-detection of three PCR products. Microfluidic chips are utilized to partition different samples into individual bottom-wells. The oil phase in the main channel contains multi-walled carbon nanotubes which were used as a heat transfer medium that absorbs energy from the IR-light-emitting diode (LED) and transfers heat to the water phase below. Cyclical rapid heating and cooling necessary for PCR are achieved by alternative power switching of the IR-LED and Universal Serial Bus (USB) mini-fan with a pulse width modulation scheme. This design of the IR-LED PCR platform is economic, compact, and fully portable, making it a promising application in the field of PoNT. The bottom-well microfluidic chip and IR-LED PCR platform were combined to fulfill a three-stage thermal cycling PCR for 40 cycles within 90 min for Human Papilloma Virus (HPV) detection. The PCR fluorescent signal was successfully captured at the end of each cycle. The technique introduced here has broad applications in nucleic acid amplification and PoNT devices.
Ong, Louis Jun Ye; Chong, Lor Huai; Jin, Lin; Singh, Pawan Kumar; Lee, Poh Seng; Yu, Hanry; Ananthanarayanan, Abhishek; Leo, Hwa Liang; Toh, Yi-Chin
The practical application of microfluidic liver models for in vitro drug testing is partly hampered by their reliance on human primary hepatocytes, which are limited in number and have batch-to-batch variation. Human stem cell-derived hepatocytes offer an attractive alternative cell source, although their 3D differentiation and maturation in a microfluidic platform have not yet been demonstrated. We develop a pump-free microfluidic 3D perfusion platform to achieve long-term and efficient differentiation of human liver progenitor cells into hepatocyte-like cells (HLCs). The device contains a micropillar array to immobilize cells three-dimensionally in a central cell culture compartment flanked by two side perfusion channels. Constant pump-free medium perfusion is accomplished by controlling the differential heights of horizontally orientated inlet and outlet media reservoirs. Computational fluid dynamic simulation is used to estimate the hydrostatic pressure heads required to achieve different perfusion flow rates, which are experimentally validated by micro-particle image velocimetry, as well as viability and functional assessments in a primary rat hepatocyte model. We perform on-chip differentiation of HepaRG, a human bipotent progenitor cell, and discover that 3D microperfusion greatly enhances the hepatocyte differentiation efficiency over static 2D and 3D cultures. However, HepaRG progenitor cells are highly sensitive to the time-point at which microperfusion is applied. Isolated HepaRG cells that are primed as static 3D spheroids before being subjected to microperfusion yield a significantly higher proportion of HLCs (92%) than direct microperfusion of isolated HepaRG cells (62%). This platform potentially offers a simple and efficient means to develop highly functional microfluidic liver models incorporating human stem cell-derived HLCs. Biotechnol. Bioeng. 2017;114: 2360-2370. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Al-Faqheri, Wisam; Ibrahim, Fatimah; Thio, Tzer Hwai Gilbert; Bahari, Norulain; Arof, Hamzah; Rothan, Hussin A; Yusof, Rohana; Madou, Marc
In this paper, we propose an easy-to-implement passive liquid valve (PLV) for the microfluidic compact-disc (CD). This valve can be implemented by introducing venting chambers to control the air flow of the source and destination chambers. The PLV mechanism is based on equalizing the main forces acting on the microfluidic CD (i.e., the centrifugal and capillary forces) to control the burst frequency of the source chamber liquid. For a better understanding of the physics behind the proposed PLV, an analytical model is described. Moreover, three parameters that control the effectiveness of the proposed valve, i.e., the liquid height, liquid density, and venting chamber position with respect to the CD center, are tested experimentally. To demonstrate the ability of the proposed PLV valve, microfluidic liquid switching and liquid metering are performed. In addition, a Bradford assay is performed to measure the protein concentration and evaluated in comparison to the benchtop procedure. The result shows that the proposed valve can be implemented in any microfluidic process that requires simplicity and accuracy. Moreover, the developed valve increases the flexibility of the centrifugal CD platform for passive control of the liquid flow without the need for an external force or trigger.
Full Text Available In this paper, we propose an easy-to-implement passive liquid valve (PLV for the microfluidic compact-disc (CD. This valve can be implemented by introducing venting chambers to control the air flow of the source and destination chambers. The PLV mechanism is based on equalizing the main forces acting on the microfluidic CD (i.e., the centrifugal and capillary forces to control the burst frequency of the source chamber liquid. For a better understanding of the physics behind the proposed PLV, an analytical model is described. Moreover, three parameters that control the effectiveness of the proposed valve, i.e., the liquid height, liquid density, and venting chamber position with respect to the CD center, are tested experimentally. To demonstrate the ability of the proposed PLV valve, microfluidic liquid switching and liquid metering are performed. In addition, a Bradford assay is performed to measure the protein concentration and evaluated in comparison to the benchtop procedure. The result shows that the proposed valve can be implemented in any microfluidic process that requires simplicity and accuracy. Moreover, the developed valve increases the flexibility of the centrifugal CD platform for passive control of the liquid flow without the need for an external force or trigger.
Coleman, Simon; Azouz, Aymen Ben; Schiphorst, Jeroen Ter; Saez, Janire; Whyte, Jeffrey; McCluskey, Peter; Kent, Nigel; Benito-Lopez, Fernando; Schenning, Albert; Diamond, Dermot
The requirement of significant off-chip fluid manipulation using high-cost mechanical components has resulted in design limitations in microfluidic devices. We report the use of novel stimuli responsive polymer gel materials for a variety of bio-inspired processes to achieve in-situ microfluidic
Dekker, Stefan; van den Berg, Albert; Odijk, Mathieu; Lee, Abraham; DeVoe, Don
This paper reports a modular microfluidic system with standardized parts, enabling rapid prototyping of lab on chip systems. Herewith contributing to the technology transfer from academy to industry. The use of standardized parts also makes it possible to design a microfluidic systems in a top down
Qian, Tongcheng; Shusta, Eric V.; Palecek, Sean P.
Microfluidic devices employ submillimeter length scale control of flow to achieve high-resolution spatial and temporal control over the microenvironment, providing powerful tools to elucidate mechanisms of human pluripotent stem cell (hPSC) regulation and to elicit desired hPSC fates. In addition, microfluidics allow control of paracrine and juxtracrine signaling, thereby enabling fabrication of microphysiological systems comprised of multiple cell types organized into organs-on-a-chip. Microfluidic cell culture systems can also be integrated with actuators and sensors, permitting construction of high-density arrays of cell-based biosensors for screening applications. This review describes recent advances in using microfluidics to understand mechanisms by which the microenvironment regulates hPSC fates and applications of microfluidics to realize the potential of hPSCs for in vitro modeling and screening applications. PMID:26313850
Phelps, Michael E. [Univ. of California, Los Angeles, CA (United States)
Radiotracer techniques are used in environmental sciences, geology, biology and medicine. Radiotracers with Positron Emission Tomography (PET) provided biological examinations of ~3 million patients 2008. Despite the success of positron labeled tracers in many sciences, there is limited access in an affordable and convenient manner to develop and use new tracers. Integrated microfluidic chips are a new technology well matched to the concentrations of tracers. Our goal is to develop microfluidic chips and new synthesis approaches to enable wide dissemination of diverse types of tracers at low cost, and to produce new generations of radiochemists for which there are many unfilled jobs. The program objectives are to: 1. Develop an integrated microfluidic platform technology for synthesizing and 18F-labeling diverse arrays of different classes of molecules. 2. Incorporate microfluidic chips into small PC controlled devices (“Synthesizer”) with a platform interfaced to PC for electronic and fluid input/out control. 3. Establish a de-centralized model with Synthesizers for discovering and producing molecular imaging probes, only requiring delivery of inexpensive [18F]fluoride ion from commercial PET radiopharmacies vs the centralized approach of cyclotron facilities synthesizing and shipping a few different types of 18F-probes. 4. Develop a position sensitive avalanche photo diode (PSAPD) camera for beta particles embedded in a microfluidic chip for imaging and measuring transport and biochemical reaction rates to valid new 18F-labeled probes in an array of cell cultures. These objectives are met within a research and educational program integrating radio-chemistry, synthetic chemistry, biochemistry, engineering and biology in the Crump Institute for Molecular Imaging. The Radiochemistry Training Program exposes PhD and post doctoral students to molecular imaging in vitro in cells and microorganisms in microfluidic chips and in vivo with PET, from new technologies
Kunze, Anja; Lengacher, Sylvain; Dirren, Elisabeth; Aebischer, Patrick; Magistretti, Pierre J; Renaud, Philippe
Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease. ALS is believed to be a non-cell autonomous condition, as other cell types, including astrocytes, have been implicated in disease pathogenesis. Hence, to facilitate the development of therapeutics against ALS, it is crucial to better understand the interactions between astrocytes and neural cells. Furthermore, cell culture assays are needed that mimic the complexity of cell to cell communication at the same time as they provide control over the different microenvironmental parameters. Here, we aim to validate a previously developed microfluidic system for an astrocyte-neuron cell culture platform, in which astrocytes have been genetically modified to overexpress either a human wild-type (WT) or a mutated form of the super oxide dismutase enzyme 1 (SOD1). Cortical neural cells were co-cultured with infected astrocytes and studied for up to two weeks. Using our microfluidic device that prevents direct cell to cell contact, we could evaluate neural cell response in the vicinity of astrocytes. We showed that neuronal cell density was reduced by about 45% when neurons were co-cultured with SOD-mutant astrocytes. Moreover, we demonstrated that SOD-WT overexpressing astrocytes reduced oxidative stress on cortical neurons that were in close metabolic contact. In contrast, cortical neurons in metabolic contact with SOD-mutant astrocytes lost their synapsin protein expression after severe glutamate treatment, an indication of the toxicity potentiating effect of the SOD-mutant enzyme.
Juul, Sissel; Nielsen, Christine Juul Fælled; Labouriau, Rodrigo
detectable at the single-molecule level. Combined with a droplet microfluidics lab-on-a-chip platform, this design allowed for sensitive, specific, and quantitative detection of all human-malaria-causing Plasmodium species in single drops of unprocessed blood with a detection limit of less than one parasite....../μL. Moreover, the setup allowed for detection of Plasmodium parasites in noninvasive saliva samples from infected patients. During recent years malaria transmission has declined worldwide, and with this the number of patients with low-parasite density has increased. Consequently, the need for accurate...
Oseev, Aleksandr; Lucklum, Ralf; Zubtsov, Mikhail; Schmidt, Marc-Peter; Mukhin, Nikolay V; Hirsch, Soeren
The current work demonstrates a novel surface acoustic wave (SAW) based phononic crystal sensor approach that allows the integration of a velocimetry-based sensor concept into single chip integrated solutions, such as Lab-on-a-Chip devices. The introduced sensor platform merges advantages of ultrasonic velocimetry analytic systems and a microacoustic sensor approach. It is based on the analysis of structural resonances in a periodic composite arrangement of microfluidic channels confined within a liquid analyte. Completed theoretical and experimental investigations show the ability to utilize periodic structure localized modes for the detection of volumetric properties of liquids and prove the efficacy of the proposed sensor concept.
Okura, Naoaki; Nakashoji, Yuta; Koshirogane, Toshihiro; Kondo, Masaki; Tanaka, Yugo; Inoue, Kohei; Hashimoto, Masahiko
We have exploited a compact and facile microfluidic droplet creation device consisting of a poly(dimethylsiloxane) microfluidic chip possessing T-junction channel geometry, two inlet reservoirs, and one outlet reservoir, and a piezoelectric (PZT) diaphragm micropump with controller. Air was evacuated from the outlet reservoir using the PZT pump, reducing the pressure inside. The reduced pressure within the outlet reservoir pulled oil and aqueous solution preloaded in the inlet reservoirs into the microchannels, which then merged at the T-junction, successfully forming water-in-oil emulsion droplets at a rate of ∼1000 per second with minimal sample loss. We confirmed that the onset of droplet formation occurred immediately after turning on the pump (<1 s). Over repeated runs, droplet formation was highly reproducible, with droplet size purity (polydispersity, <4%) comparable to that achieved using other microfluidic droplet preparation techniques. We also demonstrated single-molecule PCR amplification in the created droplets, suggesting that the device could be used for effective droplet digital PCR platforms in most laboratories without requiring great expense, space, or time for acquiring technical skills. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Zhang, Hongbo; Liu, Dongfei; Shahbazi, Mohammad-Ali; Mäkilä, Ermei; Herranz-Blanco, Bárbara; Salonen, Jarno; Hirvonen, Jouni; Santos, Hélder A
A multifunctional nano-in-micro drug delivery platform is developed by conjugating the porous silicon nanoparticles with mucoadhesive polymers and subsequent encapsulation into a pH-responsive polymer using microfluidics. The multistage platform shows monodisperse size distribution and pH-responsive payload release, and the released nanoparticles are mucoadhesive. Moreover, this platform is capable of simultaneously loading and releasing multidrugs with distinct properties. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Shapiro, Orr H.; Kramarsky-Winter, Esti; Gavish, Assaf R.; Stocker, Roman; Vardi, Assaf
Coral reefs, and the unique ecosystems they support, are facing severe threats by human activities and climate change. Our understanding of these threats is hampered by the lack of robust approaches for studying the micro-scale interactions between corals and their environment. Here we present an experimental platform, coral-on-a-chip, combining micropropagation and microfluidics to allow direct microscopic study of live coral polyps. The small and transparent coral micropropagates are ideally suited for live-imaging microscopy, while the microfluidic platform facilitates long-term visualization under controlled environmental conditions. We demonstrate the usefulness of this approach by imaging coral micropropagates at previously unattainable spatio-temporal resolutions, providing new insights into several micro-scale processes including coral calcification, coral–pathogen interaction and the loss of algal symbionts (coral bleaching). Coral-on-a-chip thus provides a powerful method for studying coral physiology in vivo at the micro-scale, opening new vistas in coral biology. PMID:26940983
Eurico Camargo Neto
Full Text Available Abstract We describe the initial results of a neonatal screening program for four lysosomal storage diseases (MPS I, Pompe, Gaucher and Fabry using the digital microfluidics methodology. The method successfully identified patients previously diagnosed with these diseases and was used to test dried blood spot samples obtained from 10,527 newborns aged 2 to 14 days. The digital microfluidic technology shows potential for a simple, rapid and high-throughput screening for these four diseases in a standard neonatal screening laboratory.
Sabourin, David; Skafte-Pedersen, Peder; Søe, Martin Jensen
A microfluidic component library for building systems driving parallel or serial microfluidic-based assays is presented. The components are a miniaturized eight-channel peristaltic pump, an eight-channel valve, sample-to-waste liquid management, and interconnections. The library of components...... of reaction chips; (2) highly parallel pumping and routing/valving capability; (3) methods to interface pumps and chip-to-liquid management systems; (4) means to construct a portable system; (5) reconfigurability/flexibility in system design; (6) means to interface to microscopes; and (7) compatibility...
Rodrigues de Sousa Nunes, Pedro André; Kjaerulff, S.; Dufva, Martin
We report on a novel microfluidic system designed to monitor in real-time the concentration of live and dead cells in industrial cell production. Custom-made stepper motor actuated peristaltic pumps and valves, fluidic interconnections, sample-to-waste liquid management and image cytometry-based ...
Groenesteijn, Jarno; de Boer, Meint J.; Lötters, Joost C.; Wiegerink, Remco J.
Microfluidic devices often require channels of a specific size and shape. These devices are then made in a fabrication process that is often specialized to produce only those (and very similar) channels. As a result, devices requiring channels of different size and shape cannot easily be integrated
Janis C. Weeks
Full Text Available The screening of candidate compounds and natural products for anthelmintic activity is important for discovering new drugs against human and animal parasites. We previously validated in Caenorhabditis elegans a microfluidic device (‘chip’ that records non-invasively the tiny electrophysiological signals generated by rhythmic contraction (pumping of the worm's pharynx. These electropharyngeograms (EPGs are recorded simultaneously from multiple worms per chip, providing a medium-throughput readout of muscular and neural activity that is especially useful for compounds targeting neurotransmitter receptors and ion channels. Microfluidic technologies have transformed C. elegans research and the goal of the current study was to validate hookworm and Ascaris suum host-stage larvae in the microfluidic EPG platform. Ancylostoma ceylanicum and A. caninum infective L3s (iL3s that had been activated in vitro generally produced erratic EPG activity under the conditions tested. In contrast, A. ceylanicum L4s recovered from hamsters exhibited robust, sustained EPG activity, consisting of three waveforms: (1 conventional pumps as seen in other nematodes; (2 rapid voltage deflections, associated with irregular contractions of the esophagus and openings of the esophogeal-intestinal valve (termed a ‘flutter’; and (3 hybrid waveforms, which we classified as pumps. For data analysis, pumps and flutters were combined and termed EPG ‘events.’ EPG waveform identification and analysis were performed semi-automatically using custom-designed software. The neuromodulator serotonin (5-hydroxytryptamine; 5HT increased EPG event frequency in A. ceylanicum L4s at an optimal concentration of 0.5 mM. The anthelmintic drug ivermectin (IVM inhibited EPG activity in a concentration-dependent manner. EPGs from A. suum L3s recovered from pig lungs exhibited robust pharyngeal pumping in 1 mM 5HT, which was inhibited by IVM. These experiments validate the use of A
Tothill, A M; Partridge, M; James, S W; Tatam, R P
A 3D-printed microfluidic device was designed and manufactured using a low cost ($2000) consumer grade fusion deposition modelling (FDM) 3D printer. FDM printers are not typically used, or are capable, of producing the fine detailed structures required for microfluidic fabrication. However, in this work, the optical transparency of the device was improved through manufacture optimisation to such a point that optical colorimetric assays can be performed in a 50 µ l device. A colorimetric enzymatic cascade assay was optimised using glucose oxidase and horseradish peroxidase for the oxidative coupling of aminoantipyrine and chromotropic acid to produce a blue quinoneimine dye with a broad absorbance peaking at 590 nm for the quantification of glucose in solution. For comparison the assay was run in standard 96 well plates with a commercial plate reader. The results show the accurate and reproducible quantification of 0–10 mM glucose solution using a 3D-printed microfluidic optical device with performance comparable to that of a plate reader assay. (paper)
Park, Jae Woo; Na, Sang Cheol; Nguyen, Thanh Qua; Paik, Sang-Min; Kang, Myeongwoo; Hong, Daewha; Choi, Insung S; Lee, Jae-Hyeok; Jeon, Noo Li
This paper describes a novel surface immobilization method for live-cell imaging of Chlamydomonas reinhardtii for continuous monitoring of lipid droplet accumulation. Microfluidics allows high-throughput manipulation and analysis of single cells in precisely controlled microenvironment. Fluorescence imaging based quantitative measurement of lipid droplet accumulation in microalgae had been difficult due to their intrinsic motile behavior. We present a simple surface immobilization method using gelatin coating as the "biological glue." We take advantage of hydroxyproline (Hyp)-based non-covalent interaction between gelatin and the outer cell wall of microalgae to anchor the cells inside the microfluidic device. We have continuously monitored single microalgal cells for up to 6 days. The immobilized microalgae remain viable (viability was comparable to bulk suspension cultured controls). When exposed to wall shear stress, most of the cells remain attached up to 0.1 dyne/cm(2) . Surface immobilization allowed high-resolution, live-cell imaging of mitotic process in real time-which followed previously reported stages in mitosis of suspension cultured cells. Use of gelatin coated microfluidics devices can result in better methods for microalgae strain screening and culture condition optimization that will help microalgal biodiesel become more economically viable. © 2014 Wiley Periodicals, Inc.
Vig, Asger Laurberg; Enevoldsen, Nikolaj; Thilsted, Anil Haraksingh; Eriksen, Johan; Kristensen, Anders; Haldrup, Kristoffer; Feidenhans'l, Robert; Nielsen, Martin Meedom
We propose and describe a microfluidic system for high intensity x-ray measurements. The required open access to a microfluidic channel is provided by an out-of-plane capillary burst valve (CBV). The functionality of the out-of-plane CBV is characterized with respect to the diameter of the windowless access hole, ranging from 10 to 130 μm. Maximum driving pressures from 22 to 280 mbar corresponding to refresh rates of the exposed sample from 300 Hz to 54 kHz is demonstrated. The microfluidic system is tested at beamline ID09b at the ESRF synchrotron radiation facility in Grenoble, and x-ray scattering measurements are shown to be feasible and to require only very limited amounts of sample, <1 ml/h of measurements without recapturing of sample. With small adjustments of the present chip design, scattering angles up to 30 deg. can be achieved without shadowing effects and integration on-chip mixing and spectroscopy appears straightforward.
Hung, Min-Sheng; Ho, Chia-Chin; Chen, Chih-Pin
This study developed a microfluidic platform for replicating and detecting DNA in real time by integrating a laser and a microfluidic device composed of polydimethylsiloxane. The design of the microchannels consisted of a laser-heating area and a detection area. An infrared laser was used as the heating source for DNA replication, and the laser power was adjusted to heat the solutions directly. In addition, strong biotin-avidin binding was used to capture and detect the replicated products. The biotin on one end was bound to avidin and anchored to the surface of the microchannels, whereas the biotin on the other end was bound to the quantum dots (Qdots). The results showed that the fluorescent intensity of the Qdots bound to the replicated products in the detection area increased with the number of thermal cycles created by the laser. When the number of thermal cycles was ≥10, the fluorescent intensity of the Qdots was directly detectable on the surface of the microchannels. The proposed method is more sensitive than detection methods entailing gel electrophoresis.
Hong, Chien-Chong; Wang, Chih-Ying; Peng, Kuo-Ti; Chu, I-Ming
This paper presents a microfluidic chip platform with electrochemical carbon nanotube electrodes for preclinical evaluation of antibiotics nanocapsules. Currently, there has been an increasing interest in the development of nanocapsules for drug delivery applications for localized treatments of diseases. So far, the methods to detect antibiotics are liquid chromatography (LC), high performance liquid chromatography (HPLC), mass spectroscopy (MS). These conventional instruments are bulky, expensive, not ease of access, and talented operator required. In order to help the development of nanocapsules and understand drug release profile before planning the clinical experiments, it is important to set up a biosensing platform which could monitor and evaluate the real-time drug release profile of nanocapsules with high sensitivity and long-term measurement ability. In this work, a microfluidic chip platform with electrochemical carbon nanotube electrodes has been developed and characterized for rapid detection of antibiotics teicoplanin nanocapsules. Multi-walled carbon nanotubes are used to modify the gold electrode surfaces to enhance the performance of the electrochemical biosensors. Experimental results show that the limit of detection of the developed platform using carbon nanotubes electrodes is 0.1 μg/ml with a linear range from 1 μg/ml to 10 μg/ml. The sensitivity of the developed system is 0.023 mA ml/μg at 37°C. The drug release profile of teicoplanin nanocapsules in PBS shows that the antibiotics nanocapsules significantly increased the release of drug on the 4th day, measuring 0.4858 μg/(ml hr). The release of drug from the antibiotics nanocapsules reached 34.98 μg/ml on the 7th day. The results showed a similar trend compared with the measurement result using the HPLC instrument. Compared with the traditional HPLC measurements, the electrochemical sensing platform we developed measures results with increased flexibility in controlling experimental
Zhang, Xin; Liu, Fei; Knapp, Karla-Anne; Nickels, Michael L; Manning, H Charles; Bellan, Leon M
Herein, we report the development of a simple, high-throughput and efficient microfluidic system for synthesizing radioactive [18F]fallypride, a PET imaging radiotracer widely used in medical research. The microfluidic chip contains all essential modules required for the synthesis and purification of radioactive fallypride. The radiochemical yield of the tracer is sufficient for multiple animal injections for preclinical imaging studies. To produce the on-chip concentration and purification columns, we employ a simple "trapping" mechanism by inserting rows of square pillars with predefined gaps near the outlet of microchannel. Microspheres with appropriate functionality are suspended in solution and loaded into the microchannels to form columns for radioactivity concentration and product purification. Instead of relying on complicated flow control elements (e.g., micromechanical valves requiring complex external pneumatic actuation), external valves are utilized to control transfer of the reagents between different modules. The on-chip ion exchange column can efficiently capture [18F]fluoride with negligible loss (∼98% trapping efficiency), and subsequently release a burst of concentrated [18F]fluoride to the reaction cavity. A thin layer of PDMS with a small hole in the center facilitates rapid and reliable water evaporation (with the aid of azeotropic distillation and nitrogen flow) while reducing fluoride loss. During the solvent exchange and fluorination reaction, the entire chip is uniformly heated to the desired temperature using a hot plate. All aspects of the [18F]fallypride synthesis were monitored by high-performance liquid chromatography (HPLC) analysis, resulting in labelling efficiency in fluorination reaction ranging from 67-87% (n = 5). Moreover, after isolating unreacted [18F]fluoride, remaining fallypride precursor, and various by-products via an on-chip purification column, the eluted [18F]fallypride is radiochemically pure and of a sufficient
Muñoz-Hernando, M.; Macias, P.; Abella, M.; Desco, M.; Sharpe, S.; Vaquero, J.J.; Muñoz-Barrutia, M.
Cancer is a leading cause of mortality in the world, with osteosarcoma being one of the most common types among children between 1 and 14 years old. The use of lipid nanoparticles as biodegradable shells for controlled drug delivery shows promise as a more effective and targeted tumor treatment. However, current techniques for in vitro testing of these vehicles have shown little validity due to their static nature, in which nanoparticles sediment onto the bottom of the wells and kill the cells via asphyxiation, hiding the real effect achieved by the nanoparticles. In this work, a microfluidic platform capable of determining the optimum dose of methotrexate-loaded lipid nanoparticles in osteosarcoma treatment is presented as a promising alternative to current nanoparticle characterization assays. (Author)
Tirandazi, Pooyan; Healy, John; Hidrovo, Carlos H.
In-air droplet formation inside microfluidic networks is an alternative technique to the conventional in-liquid systems for creating uniform, microscale droplets. Recent works have highlighted and quantified the use of a gaseous continuous phase for controlled generation of droplets in the Dripping regime in planar structures. Here we demonstrate a new class of non-planar droplet-based systems which rely on controlled breakup of a liquid microjet within a high speed flow of air inside a confined microfluidic flow-focusing PDMS channel. We investigate the physics of confined gas-liquid flows and the effect of geometry on the behavior of a liquid water jet in a gaseous flow. Droplet breakup in the Jetting regime is studied both numerically and experimentally and the results are compared. We show droplet production capability at rates higher than 100 KHz with droplets ranging from 15-30 μm in diameter and a polydispersity index of less than 15%. This work represents an important investigation into the Jetting regime in confined microchannels. The ability to control jet behavior, generation rate, and droplet size in gas-liquid microflows will further expand the potential applications of this system for high throughput operations in material synthesis and biochemical analysis. We acknowledge funding support from NSF CAREER Award Grant CBET-1522841.
Full Text Available Phospholipid-based deformable nanovesicles (DNVs that have flexibility in shape offer an adaptable and facile method to encapsulate diverse classes of therapeutics and facilitate localized transdermal delivery while minimizing systemic exposure. Here we report the use of a microfluidic reactor for the synthesis of DNVs and show that alteration of input parameters such as flow speeds as well as molar and flow rate ratios increases entrapment efficiency of drugs and allows fine-tuning of DNV size, elasticity, and surface charge. To determine the ability of DNV-encapsulated drug to be delivered transdermally to a local site, we synthesized, characterized, and tested DNVs carrying the fluorescently labeled hydrophilic bisphosphonate drug AF-647 zoledronate (AF647-Zol. AF647-Zol DNVs were lyophilized, resuspended, and applied topically as a paste to the calvarial skin of mice. High-resolution fluorescent imaging and confocal microscopy revealed significant increase of encapsulated payload delivery to the target tissue—cranial bone—by DNVs as compared to nondeformable nanovesicles (NVs or aqueous drug solutions. Interestingly, NV delivery was not superior to aqueous drug solution. Our studies show that microfluidic reactor-synthesized DNVs can be produced in good yield, with high encapsulation efficiency, reproducibility, and stability after storage, and represent a useful vehicle for localized transdermal drug delivery.
Kokalj, Tadej; Pérez-Ruiz, Elena; Lammertyn, Jeroen
Digital microfluidics (DMF) has emerged as a promising liquid handling technology for a variety of applications, demonstrating great potential both in terms of miniaturization and automation. DMF is based on the manipulation of discrete, independently controllable liquid droplets, which makes it highly reconfigurable and reprogrammable. One of its most exclusive advantages, compared to microchannel-based microfluidics, is its ability to precisely handle solid nano- and microsized objects, such as magnetic particles. Magnetic particles have become very popular in the last decade, since their high surface-to-volume ratio and the possibility to magnetically separate them from the matrix make them perfect suitable as a solid support for bio-assay development. The potential of magnetic particles in DMF-based bio-assays has been demonstrated for various applications. In this review we discuss the latest developments of magnetic particle-based DMF bio-assays with the aim to present, identify and analyze the trends in the field. We also discuss the state-of-the art of device integration, current status of commercialization and issues that still need to be addressed. With this paper we intend to stimulate researchers to exploit and unveil the potential of these exciting tools, which will shape the future of modern biochemistry, microbiology and biomedical diagnostics. Copyright © 2015 Elsevier B.V. All rights reserved.
Burger, J.; Gross, A.; Mark, D.; Roth, G.; von Stetten, F.; Zengerle, R.
The direct on-disk wireless temperature measurement system [1,2] presented at μTAS 2010 was further improved in its robustness. We apply it to an IR thermocycler as part of a centrifugal microfluidic analyzer for polymerase chain reactions (PCR). This IR thermocycler allows the very efficient direct heating of aqueous liquids in microfluidic cavities by an IR radiation source. The efficiency factor of this IR heating system depends on several parameters. First there is the efficiency of the IR radiator considering the transformation of electrical energy into radiation energy. This radiation energy needs to be focused by a reflector to the center of the cavity. Both, the reflectors shape and the quality of the reflecting layer affect the efficiency. On the way to the center of the cavity the radiation energy will be diminished by absorption in the surrounding air/humidity and especially in the cavity lid of the microfluidic disk. The transmission spectrum of the lid material and its thickness is of significant impact. We chose a COC polymer film with a thickness of 150 μm. At a peak frequency of the IR radiator of ~2 μm approximately 85 % of the incoming radiation energy passes the lid and is absorbed within the first 1.5 mm depth of liquid in the cavity. As we perform the thermocycling for a PCR, after heating to the denaturation temperature of ~ 92 °C we need to cool down rapidly to the primer annealing temperature of ~ 55 °C. Cooling is realized by 3 ventilators venting air of room temperature into the disk chamber. Due to the air flow itself and an additional rotation of the centrifugal microfluidic disk the PCR reagents in the cavities are cooled by forced air convection. Simulation studies based upon analogous electrical models enable to optimize the disk geometry and the optical path. Both the IR heater and the ventilators are controlled by the digital PID controller HAPRO 0135 . The sampling frequency is set to 2 Hz. It could be further increased up
Silva, D F C; Azevedo, A M; Fernandes, P; Chu, V; Conde, J P; Aires-Barros, M R
Aqueous two phase systems (ATPS) offer great potential for selective separation of a wide range of biomolecules by exploring differences in molecular solubility in each of the two immiscible phases. However, ATPS use has been limited due to the difficulty in predicting the behavior of a given biomolecule in the partition environment together with the empirical and time-consuming techniques that are used for the determination of partition and extraction parameters. In this work, a fast and novel technique based on a microfluidic platform and using fluorescence microscopy was developed to determine the partition coefficients of biomolecules in different ATPS. This method consists of using a microfluidic device with a single microchannel and three inlets. In two of the inlets, solutions containing the ATPS forming components were loaded while the third inlet was fed with the FITC tagged biomolecule of interest prepared in milli-Q water. Using fluorescence microscopy, it was possible to follow the location of the FITC-tagged biomolecule and, by simply varying the pumping rates of the solutions, to quickly test a wide variety of ATPS compositions. The ATPS system is allowed 4min for stabilization and fluorescence micrographs are used to determine the partition coefficient.The partition coefficients obtained were shown to be consistent with results from macroscale ATPS partition. This process allows for faster screening of partition coefficients using only a few microliters of material for each ATPS composition and is amenable to automation. The partitioning behavior of several biomolecules with molecular weights (MW) ranging from 5.8 to 150kDa, and isoelectric points (pI) ranging from 4.7 to 6.4 was investigated, as well as the effect of the molecular weight of the polymer ATPS component. Copyright © 2016 Elsevier B.V. All rights reserved.
Zor, Kinga; Heiskanen, Arto; Caviglia, Claudia
and electrochemical analysis platform with in-built fluid handling and detection, enabling complete cell based assays comprising on-line electrode cleaning, sterilization, surface functionalization, cell seeding, cultivation and electrochemical real-time monitoring of cellular dynamics. To demonstrate the versatility...... capability. The here presented platform is aimed at applications utilizing cell based assays, ranging from e.g. monitoring of drug effects in pharmacological studies, characterization of neural stem cell differentiation, and screening of genetically modified microorganisms to environmental monitoring....
Wright, Evan [University of Guelph, Canada; Neethirajan, Suresh [University of Guelph; Warriner, Keith [University of Guelph; Retterer, Scott T [ORNL; Srijanto, Bernadeta R [ORNL
Listeria monocytogenes remains a significant foodborne pathogen due to its virulence and ability to become established in food processing facilities. The pathogen is characterized by its ability to grow over a wide temperature range and withstand a broad range of stresses. The following reports on the chemotaxis and motility of the L. monocytogenes when exposed to relatively small concentrations of acetic acid. Using the developed nanoporous microfluidic device to precisely modulate the cellular environment, we exposed the individual Listeria cells to acetic acid and, in real time and with high resolution, observed how the cells reacted to the change in their surroundings. Our results showed that concentrations of acetic acid below 10 mM had very little, if any, effect on the motility. However, when exposed to 100 mM acetic acid, the cells exhibited a sharp drop in velocity and displayed a more random pattern of motion. These results indicate that at appropriate concentrations, acetic acid has the ability to disable the flagellum of the cells, thus impairing their motility. This drop in motility has numerous effects on the cell; its main effects being the obstruction of the cell's ability to properly form biofilms and a reduction in the overall infectivity of the cells. Since these characteristics are especially useful in controlling the proliferation of L. monocytogenes, acetic acid shows potential for application in the food industry as an active compound in designing a food packaging environment and as an antimicrobial agent.
Shah Mukim Uddin
Full Text Available In recent years, many improvements have been made in foodborne pathogen detection methods to reduce the impact of food contamination. Several rapid methods have been developed with biosensor devices to improve the way of performing pathogen detection. This paper presents an automated endpoint detection system for amplicons generated by loop mediated isothermal amplification (LAMP on a microfluidic compact disk platform. The developed detection system utilizes a monochromatic ultraviolet (UV emitter for excitation of fluorescent labeled LAMP amplicons and a color sensor to detect the emitted florescence from target. Then it processes the sensor output and displays the detection results on liquid crystal display (LCD. The sensitivity test has been performed with detection limit up to 2.5 × 10−3 ng/µL with different DNA concentrations of Salmonella bacteria. This system allows a rapid and automatic endpoint detection which could lead to the development of a point-of-care diagnosis device for foodborne pathogens detection in a resource-limited environment.
Magdalena K. Bielecka
Full Text Available Antimicrobial resistance presents one of the most significant threats to human health, with the emergence of totally drug-resistant organisms. We have combined bioengineering, genetically modified bacteria, longitudinal readouts, and fluidics to develop a transformative platform to address the drug development bottleneck, utilizing Mycobacterium tuberculosis as the model organism. We generated microspheres incorporating virulent reporter bacilli, primary human cells, and an extracellular matrix by using bioelectrospray methodology. Granulomas form within the three-dimensional matrix, and mycobacterial stress genes are upregulated. Pyrazinamide, a vital first-line antibiotic for treating human tuberculosis, kills M. tuberculosis in a three-dimensional culture but not in a standard two-dimensional culture or Middlebrook 7H9 broth, demonstrating that antibiotic sensitivity within microspheres reflects conditions in patients. We then performed pharmacokinetic modeling by combining the microsphere system with a microfluidic plate and demonstrated that we can model the effect of dynamic antibiotic concentrations on mycobacterial killing. The microsphere system is highly tractable, permitting variation of cell content, the extracellular matrix, sphere size, the infectious dose, and the surrounding medium with the potential to address a wide array of human infections and the threat of antimicrobial resistance.
Gorbatsova, Jelena; Jaanus, Martin; Vaher, Merike; Kaljurand, Mihkel
In this work, the concept of a field-portable analyzer is proposed that operates with milliliter amounts of solvents and samples. The need to develop such an analyzer is not only driven by specific extraterrestrial analysis but also, for example, by forensics applications where the amount of liquid that can be taken to the field is severely limited. The prototype of the proposed analyzer consists of a solid-liquid extractor, the output of which is connected to the micropump, which delivers droplets of extracts to digital microfluidic platform (DMFP). In this way, world-to-chip interfacing is established. Further, the sample droplets are transported to CE capillary inlet port, separated and detected via a contactless conductivity detector. Working buffers and other solvents needed to perform CE analysis are also delivered as droplets to the DMFP and transported through the CE capillary. The performance of the analyzer is demonstrated by analysis of amino acids in sand matrices. The recovery of the spiked amino acids from the inert sand sample was from 34 to 51% with analysis LOD from 0.2 to 0.6 ppm and migration time RSD from 0.2 to 6.0%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Thuy, Tran Thi; Tengstrand, Erik; Aberg, Magnus; Thorsén, Gunnar
Optimal glycosylation with respect to the efficacy, serum half-life time, and immunogenic properties is essential in the generation of therapeutic antibodies. The glycosylation pattern can be affected by several different parameters during the manufacture of antibodies and may change significantly over cultivation time. Fast and robust methods for determination of the glycosylation patterns of therapeutic antibodies are therefore needed. We have recently presented an efficient method for the determination of glycans on therapeutic antibodies using a microfluidic CD platform for sample preparation prior to matrix-assisted laser-desorption mass spectrometry analysis. In the present work, this method is applied to analyse the glycosylation patterns of three commercially available therapeutic antibodies and one intended for therapeutic use. Two of the antibodies produced in mouse myeloma cell line (SP2/0) and one produced in Chinese hamster ovary (CHO) cells exhibited similar glycosylation patterns but could still be readily differentiated from each other using multivariate statistical methods. The two antibodies with most similar glycosylation patterns were also studied in an assessment of the method's applicability for quality control of therapeutic antibodies. The method presented in this paper is highly automated and rapid. It can therefore efficiently generate data that helps to keep a production process within the desired design space or assess that an identical product is being produced after changes to the process. Copyright © 2012 Elsevier B.V. All rights reserved.
Maschmeyer, Ilka; Hasenberg, Tobias; Jaenicke, Annika; Lindner, Marcus; Lorenz, Alexandra Katharina; Zech, Julie; Garbe, Leif-Alexander; Sonntag, Frank; Hayden, Patrick; Ayehunie, Seyoum; Lauster, Roland; Marx, Uwe; Materne, Eva-Maria
Systemic repeated dose safety assessment and systemic efficacy evaluation of substances are currently carried out on laboratory animals and in humans due to the lack of predictive alternatives. Relevant international regulations, such as OECD and ICH guidelines, demand long-term testing and oral, dermal, inhalation, and systemic exposure routes for such evaluations. So-called "human-on-a-chip" concepts are aiming to replace respective animals and humans in substance evaluation with miniaturized functional human organisms. The major technical hurdle toward success in this field is the life-like combination of human barrier organ models, such as intestine, lung or skin, with parenchymal organ equivalents, such as liver, at the smallest biologically acceptable scale. Here, we report on a reproducible homeostatic long-term co-culture of human liver equivalents with either a reconstructed human intestinal barrier model or a human skin biopsy applying a microphysiological system. We used a multi-organ chip (MOC) platform, which provides pulsatile fluid flow within physiological ranges at low media-to-tissue ratios. The MOC supports submerse cultivation of an intact intestinal barrier model and an air-liquid interface for the skin model during their co-culture with the liver equivalents respectively at (1)/100.000 the scale of their human counterparts in vivo. To increase the degree of organismal emulation, microfluidic channels of the liver-skin co-culture could be successfully covered with human endothelial cells, thus mimicking human vasculature, for the first time. Finally, exposure routes emulating oral and systemic administration in humans have been qualified by applying a repeated dose administration of a model substance - troglitazone - to the chip-based co-cultures. Copyright © 2015. Published by Elsevier B.V.
Bsoul, Anas; Pan, Sheng; Cretu, Edmond; Stoeber, Boris; Walus, Konrad
In this paper, we present a disposable inkjet dispenser platform technology and demonstrate the Lab-on-a-Printer concept, an extension of the ubiquitous Lab-on-a-Chip concept, whereby microfluidic modules are directly integrated into the printhead. The concept is demonstrated here through the integration of an inkjet dispenser and a microfluidic mixer enabling control over droplet composition from a single nozzle in real-time during printing. The inkjet dispenser is based on a modular design platform that enables the low-cost microfluidic component and the more expensive actuation unit to be easily separated, allowing for the optional disposal of the former and reuse of the latter. To limit satellite droplet formation, a hydrophobic-coated and tapered micronozzle was microfabricated and integrated with the fluidics to realize the dispenser. The microfabricated devices generated droplets with diameters ranging from 150-220 μm, depending mainly on the orifice diameter, with printing rates up to 8000 droplets per second. The inkjet dispenser is capable of dispensing materials with a viscosity up to ∼19 mPa s. As a demonstration of the inkjet dispenser function and application, we have printed type I collagen seeded with human liver carcinoma cells (cell line HepG2), to form patterned biological structures.
Ahmad, Habib; Sutherland, Alex; Shin, Young Shik; Hwang, Kiwook; Qin, Lidong; Krom, Russell-John; Heath, James R.
Microfluidics flow-patterning has been utilized for the construction of chip-scale miniaturized DNA and protein barcode arrays. Such arrays have been used for specific clinical and fundamental investigations in which many proteins are assayed from single cells or other small sample sizes. However, flow-patterned arrays are hand-prepared, and so are impractical for broad applications. We describe an integrated robotics/microfluidics platform for the automated preparation of such arrays, and we apply it to the batch fabrication of up to eighteen chips of flow-patterned DNA barcodes. The resulting substrates are comparable in quality with hand-made arrays and exhibit excellent substrate-to-substrate consistency. We demonstrate the utility and reproducibility of robotics-patterned barcodes by utilizing two flow-patterned chips for highly parallel assays of a panel of secreted proteins from single macrophage cells.
Ahmad, Habib; Sutherland, Alex; Shin, Young Shik; Hwang, Kiwook; Qin, Lidong; Krom, Russell-John; Heath, James R
Microfluidics flow-patterning has been utilized for the construction of chip-scale miniaturized DNA and protein barcode arrays. Such arrays have been used for specific clinical and fundamental investigations in which many proteins are assayed from single cells or other small sample sizes. However, flow-patterned arrays are hand-prepared, and so are impractical for broad applications. We describe an integrated robotics/microfluidics platform for the automated preparation of such arrays, and we apply it to the batch fabrication of up to eighteen chips of flow-patterned DNA barcodes. The resulting substrates are comparable in quality with hand-made arrays and exhibit excellent substrate-to-substrate consistency. We demonstrate the utility and reproducibility of robotics-patterned barcodes by utilizing two flow-patterned chips for highly parallel assays of a panel of secreted proteins from single macrophage cells. © 2011 American Institute of Physics
Vergauwe, Nicolas; Witters, Daan; Ceyssens, Frederik; Vermeir, Steven; Verbruggen, Bert; Puers, Robert; Lammertyn, Jeroen
Electrowetting-on-dielectric (EWOD) lab-on-a-chip systems have already proven their potential within a broad range of bio-assays. Nevertheless, research on the analytical performance of those systems is limited, yet crucial for a further breakthrough in the diagnostic field. Therefore, this paper presents the intrinsic possibilities of an EWOD lab-on-a-chip as a versatile platform for homogeneous and heterogeneous bio-assays with high analytical performance. Both droplet dispensing and splitting cause variations in droplet size, thereby directly influencing the assay's performance. The extent to which they influence the performance is assessed by a theoretical sensitivity analysis, which allows the definition of a basic framework for the reduction of droplet size variability. Taking advantage of the optimized droplet manipulations, both homogeneous and heterogeneous bio-assays are implemented in the EWOD lab-on-a-chip to demonstrate the analytical capabilities and versatility of the device. A fully on-chip enzymatic assay is realized with high analytical performance. It demonstrates the promising capabilities of an EWOD lab-on-a-chip in food-related and medical applications, such as nutritional and blood analyses. Further, a magnetic bio-assay for IgE detection using superparamagnetic nanoparticles is presented whereby the nanoparticles are used as solid carriers during the bio-assay. Crucial elements are the precise manipulation of the superparamagnetic nanoparticles with respect to dispensing and separation. Although the principle of using nano-carriers is demonstrated for protein detection, it can be easily extended to a broader range of bio-related applications like DNA sensing. In heterogeneous bio-assays the chip surface is actively involved during the execution of the bio-assay. Through immobilization of specific biological compounds like DNA, proteins and cells a reactive chip surface is realized, which enhances the bio-assay performance. To demonstrate
Durucan, Onur; Morelli, Lidia; Schmidt, Michael Stenbæk
In this work we present a novel technology that combines the advantages of centrifugal microfluidics with dynamic in-situ Surface Enhanced Raman Spectroscopy (SERS) sensing. Our technology is based on an automated readout system that allows on-line SERS acquisition on a rotating centrifugal...
The screening of candidate compounds and natural products for anthelmintic activity is a key component of discovering new drugs against human and animal parasites. We previously validated in Caenorhabditis elegans a microfluidic device (‘chip’) that records non-invasively the tiny electrophysiologic...
Titmarsh, Drew M.; Chen, Huaying; Glass, Nick R.; Cooper-White, Justin J.
Stem cells are a powerful resource for producing a variety of cell types with utility in clinically associated applications, including preclinical drug screening and development, disease and developmental modeling, and regenerative medicine. Regardless of the type of stem cell, substantial barriers to clinical translation still exist and must be overcome to realize full clinical potential. These barriers span processes including cell isolation, expansion, and differentiation; purification, quality control, and therapeutic efficacy and safety; and the economic viability of bioprocesses for production of functional cell products. Microfluidic systems have been developed for a myriad of biological applications and have the intrinsic capability of controlling and interrogating the cellular microenvironment with unrivalled precision; therefore, they have particular relevance to overcoming such barriers to translation. Development of microfluidic technologies increasingly utilizes stem cells, addresses stem cell-relevant biological phenomena, and aligns capabilities with translational challenges and goals. In this concise review, we describe how microfluidic technologies can contribute to the translation of stem cell research outcomes, and we provide an update on innovative research efforts in this area. This timely convergence of stem cell translational challenges and microfluidic capabilities means that there is now an opportunity for both disciplines to benefit from increased interaction. PMID:24311699
Chen, Jinyang; Ji, Xinghu; He, Zhike
In this work, a simple, flexible and low-cost sample-introduction technique was developed and integrated with droplet platform. The sample-introduction strategy was realized based on connecting the components of positive pressure input device, sample container and microfluidic chip through the tygon tubing with homemade polydimethylsiloxane (PDMS) adaptor, so the sample was delivered into the microchip from the sample container under the driving of positive pressure. This sample-introduction technique is so robust and compatible that could be integrated with T-junction, flow-focus or valve-assisted droplet microchips. By choosing the PDMS adaptor with proper dimension, the microchip could be flexibly equipped with various types of familiar sample containers, makes the sampling more straightforward without trivial sample transfer or loading. And the convenient sample changing was easily achieved by positioning the adaptor from one sample container to another. Benefiting from the proposed technique, the time-dependent concentration gradient was generated and applied for quantum dot (QD)-based fluorescence barcoding within droplet chip. High-throughput droplet screening was preliminarily demonstrated through the investigation of the quenching efficiency of ruthenium complex to the fluorescence of QD. More importantly, multiplex DNA assay was successfully carried out in the integrated system, which shows the practicability and potentials in high-throughput biosensing. - Highlights: • A simple, robust and low-cost sample-introduction technique was developed. • Convenient and flexible sample changing was achieved in microfluidic system. • Novel strategy of concentration gradient generation was presented for barcoding. • High-throughput droplet screening could be realized in the integrated platform. • Multiplex DNA assay was successfully carried out in the droplet platform
Chen, Jinyang; Ji, Xinghu [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); He, Zhike, E-mail: email@example.com [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Suzhou Institute of Wuhan University, Suzhou 215123 (China)
In this work, a simple, flexible and low-cost sample-introduction technique was developed and integrated with droplet platform. The sample-introduction strategy was realized based on connecting the components of positive pressure input device, sample container and microfluidic chip through the tygon tubing with homemade polydimethylsiloxane (PDMS) adaptor, so the sample was delivered into the microchip from the sample container under the driving of positive pressure. This sample-introduction technique is so robust and compatible that could be integrated with T-junction, flow-focus or valve-assisted droplet microchips. By choosing the PDMS adaptor with proper dimension, the microchip could be flexibly equipped with various types of familiar sample containers, makes the sampling more straightforward without trivial sample transfer or loading. And the convenient sample changing was easily achieved by positioning the adaptor from one sample container to another. Benefiting from the proposed technique, the time-dependent concentration gradient was generated and applied for quantum dot (QD)-based fluorescence barcoding within droplet chip. High-throughput droplet screening was preliminarily demonstrated through the investigation of the quenching efficiency of ruthenium complex to the fluorescence of QD. More importantly, multiplex DNA assay was successfully carried out in the integrated system, which shows the practicability and potentials in high-throughput biosensing. - Highlights: • A simple, robust and low-cost sample-introduction technique was developed. • Convenient and flexible sample changing was achieved in microfluidic system. • Novel strategy of concentration gradient generation was presented for barcoding. • High-throughput droplet screening could be realized in the integrated platform. • Multiplex DNA assay was successfully carried out in the droplet platform.
Li, Wei; Liu, Dongfei; Zhang, Hongbo; Correia, Alexandra; Mäkilä, Ermei; Salonen, Jarno; Hirvonen, Jouni; Santos, Hélder A
Harsh conditions of the gastrointestinal tract hinder the oral delivery of many drugs. Developing oral drug delivery systems based on commercially available materials is becoming more challenging due to the demand for simultaneously delivering physicochemically different drugs for treating complex diseases. A novel architecture, namely nanotube-in-microsphere, was developed as a drug delivery platform by encapsulating halloysite nanotubes (HNTs) in a pH-responsive hydroxypropyl methylcellulose acetate succinate polymer using microfluidics. HNTs were selected as orally acceptable clay mineral and their lumen was enlarged by selective acid etching. Model drugs (atorvastatin and celecoxib) with different physicochemical properties and synergistic effect on colon cancer prevention and inhibition were simultaneously incorporated into the microspheres at a precise ratio, with atorvastatin and celecoxib being loaded in the HNTs and polymer matrix, respectively. The microspheres showed spherical shape, narrow particle size distribution and pH-responsive dissolution behavior. This nanotube/pH-responsive polymer composite protected the loaded drugs from premature release at pH⩽6.5, but allowed their fast release and enhanced the drug permeability, and the inhibition of colon cancer cell proliferation at pH 7.4. Overall, the nano-in-micro drug delivery composite fabricated by microfluidics is a promising and flexible platform for the delivery of multiple drugs for combination therapy. Halloysite nanotubes (HNTs) are attracting increasing attention for drug delivery applications. However, conventional HNTs-based oral drug delivery systems are lack of the capability to precisely control the drug release at a desired site in the gastrointestinal tract. In this study, a nanotube-in-microsphere drug delivery platform is developed by encapsulating HNTs in a pH-responsive polymer using microfluidics. Drugs with different physicochemical properties and synergistic effect on colon
Kook, Yun-Min; Jeong, Yoon; Lee, Kangwon; Koh, Won-Gun
The extracellular matrix of most natural tissues comprises various types of cells, including fibroblasts, stem cells, and endothelial cells, which communicate with each other directly or indirectly to regulate matrix production and cell functionality. To engineer multicellular interactions in vitro, co-culture systems have achieved tremendous success achieving a more realistic microenvironment of in vivo metabolism than monoculture system in the past several decades. Recently, the fields of tissue engineering and regenerative medicine have primarily focused on three-dimensional co-culture systems using cellular scaffolds, because of their physical and biological relevance to the extracellular matrix of actual tissues. This review discusses several materials and methods to create co-culture systems, including hydrogels, electrospun fibers, microfluidic devices, and patterning for biomimetic co-culture system and their applications for specific tissue regeneration. Consequently, we believe that culture systems with appropriate physical and biochemical properties should be developed, and direct or indirect cell–cell interactions in the remodeled tissue must be considered to obtain an optimal tissue-specific microenvironment. PMID:29081966
Rodrigues de Sousa Nunes, Pedro André; Kjaerulff, S.; Dufva, Martin
system performance by monitoring in real time the cell concentration and viability of yeast extracted directly from an in-house made bioreactor. This is the first demonstration of using the Dean drag force, generated due to the implementation of a curved microchannel geometry in conjunction with high...... flow rates, to promote passive mixing of cell samples and thus homogenization of the diluted cell plug. The autonomous operation of the fluidics furthermore allows implementation of intelligent protocols for administering air bubbles from the bioreactor in the microfluidic system, so...... and thereby ensure optimal cell production, by prolonging the fermentation cycle and increasing the bioreactor output. In this work, we report on the development of a fully automated microfluidic system capable of extracting samples directly from a bioreactor, diluting the sample, staining the cells...
Esquivel, J P; Colomer-Farrarons, J; Castellarnau, M; Salleras, M; del Campo, F J; Samitier, J; Miribel-Català, P; Sabaté, N
The present paper reports for the first time the integration of a microfluidic system, electronics modules, amperometric sensor and display, all powered by a single micro direct methanol fuel cell. In addition to activating the electronic circuitry, the integrated power source also acts as a tuneable micropump. The electronics fulfil several functions. First, they regulate the micro fuel cell output power, which off-gas controls the flow rate of different solutions toward an electrochemical sensor through microfluidic channels. Secondly, as the fuel cell powers a three-electrode electrochemical cell, the electronics compare the working electrode output signal with a set reference value. Thirdly, if the concentration measured by the sensor exceeds this threshold value, the electronics switch on an integrated organic display. This integrated approach pushes forward the development of truly autonomous point-of-care devices relying on electrochemical detection.
Ding, Zhaoxiong; Zhang, Dongying; Wang, Guanghui; Tang, Minghui; Dong, Yumin; Zhang, Yixin; Ho, Ho-Pui; Zhang, Xuping
In this paper, an in-line, low-cost, miniature and portable spectrophotometric detection system is presented and used for fast protein determination and calibration in centrifugal microfluidics. Our portable detection system is configured with paired emitter and detector diodes (PEDD), where the light beam between both LEDs is collimated with enhanced system tolerance. It is the first time that a physical model of PEDD is clearly presented, which could be modelled as a photosensitive RC oscillator. A portable centrifugal microfluidic system that contains a wireless port in real-time communication with a smartphone has been built to show that PEDD is an effective strategy for conducting rapid protein bioassays with detection performance comparable to that of a UV-vis spectrophotometer. The choice of centrifugal microfluidics offers the unique benefits of highly parallel fluidic actuation at high accuracy while there is no need for a pump, as inertial forces are present within the entire spinning disc and accurately controlled by varying the spinning speed. As a demonstration experiment, we have conducted the Bradford assay for bovine serum albumin (BSA) concentration calibration from 0 to 2 mg mL(-1). Moreover, a novel centrifugal disc with a spiral microchannel is proposed for automatic distribution and metering of the sample to all the parallel reactions at one time. The reported lab-on-a-disc scheme with PEDD detection may offer a solution for high-throughput assays, such as protein density calibration, drug screening and drug solubility measurement that require the handling of a large number of reactions in parallel.
Tsaloglou, Maria-Nefeli; Laouenan, Florian; Loukas, Christos-Moritz; Monsalve, Lisandro Gabriel; Thanner, Christine; Morgan, Hywel; Ruano-López, Jesus M; Mowlem, Matthew C
Quantitation of specific RNA sequences is a useful technique in marine biology that can elucidate cell abundance, speciation and viability, especially for early detection of harmful algal blooms. We are thus developing an integrated microfluidic system for cell concentration and lysis, RNA extraction/purification and quantitative RNA detection for environmental applications. The portable system is based on a microfluidic cartridge, or "lab-card", using a low-cost injection moulded device, with a laminated lid. Here we present real-time isothermal RNA amplification using reagent master-mixes preserved on-chip in a gel at 4 °C for up to eight months. We demonstrate quantitation by reference to an internal control in a competitive assay with 500 cell equivalents of the toxic microalga Karenia brevis. Annealing of primers, amplification at 41 °C and real-time fluorescence detection of the internal control and target using sequence-specific molecular beacons were all performed on-chip.
Full Text Available In native fibrocartilage, mechanotransduction allows the cells to perceive the physical microenvironment not only through topographical cues from the extracellular matrix, but also through mechanical cues, such as interstitial flow. To create a microenvironment that simultaneously integrates nanotopography and flow stimulus, we developed a biomimetic microfluidic device embedded with aligned nanofibers to contain microchambers of different angles, which enabled the flow direction to form different angles with the fibers. Using this device, we investigated the effects of microfluidic and nanotopographical environment on the morphology and fibrochondrogenesis of mesenchymal stem cells (MSCs and the involvement of RhoA/ROCK pathway and Yes-associated protein (YAP/transcriptional co-activator with PDZ-binding motif (TAZ. The results showed that the flow direction perpendicular to aligned nanofibers was conducive to fibrochondrogenesis of MSCs. In addition, ROCK inhibitor and knockdown of YAP/TAZ disrupted fibrochondrogenic differentiation of MSCs. In conclusion, our data suggest the crucial role of mechanotransduction in regulating fibrochondrogenic differentiation of MSCs, which may be mediated by RhoA/ROCK pathway and YAP/TAZ.
Poulsen, Carl Esben; Wootton, Robert C. R.; Wolff, Anders
The determination of pharmacokinetic properties of drugs, such as the distribution coefficient, D, is a crucial measurement in pharmaceutical research. Surprisingly, the conventional (gold standard) technique used for D measurements, the shake-flask method, is antiquated and unsuitable...... for the testing of valuable and scarce drug candidates. Herein we present a simple micro fluidic platform for the determination of distribution coefficients using droplet-based liquid-liquid extraction. For simplicity, this platform makes use of gravity to enable phase separation for analysis and is 48 times...... the apparent acid dissociation constant, pK', as a proxy for inter-system comparison. Our platform determines a pK' value of 7.24 ± 0.15, compared to 7.25 ± 0.58 for the shake-flask method in our hands and 7.21 for the shake-flask method in literature. Devices are fabricated using injection moulding, the batch...
Lignos, Ioannis; Morad, Viktoriia; Shynkarenko, Yevhen; Bernasconi, Caterina; Maceiczyk, Richard M; Protesescu, Loredana; Bertolotti, Federica; Kumar, Sudhir; Ochsenbein, Stefan T; Masciocchi, Norberto; Guagliardi, Antonietta; Shih, Chih-Jen; Bodnarchuk, Maryna I; deMello, Andrew J; Kovalenko, Maksym V
Hybrid organic-inorganic and fully inorganic lead halide perovskite nanocrystals (NCs) have recently emerged as versatile solution-processable light-emitting and light-harvesting optoelectronic materials. A particularly difficult challenge lies in warranting the practical utility of such semiconductor NCs in the red and infrared spectral regions. In this context, all three archetypal A-site monocationic perovskites-CH 3 NH 3 PbI 3 , CH(NH 2 ) 2 PbI 3 , and CsPbI 3 -suffer from either chemical or thermodynamic instabilities in their bulk form. A promising approach toward the mitigation of these challenges lies in the formation of multinary compositions (mixed cation and mixed anion). In the case of multinary colloidal NCs, such as quinary Cs x FA 1- x Pb(Br 1- y I y ) 3 NCs, the outcome of the synthesis is defined by a complex interplay between the bulk thermodynamics of the solid solutions, crystal surface energies, energetics, dynamics of capping ligands, and the multiple effects of the reagents in solution. Accordingly, the rational synthesis of such NCs is a formidable challenge. Herein, we show that droplet-based microfluidics can successfully tackle this problem and synthesize Cs x FA 1- x PbI 3 and Cs x FA 1- x Pb(Br 1- y I y ) 3 NCs in both a time- and cost-efficient manner. Rapid in situ photoluminescence and absorption measurements allow for thorough parametric screening, thereby permitting precise optical engineering of these NCs. In this showcase study, we fine-tune the photoluminescence maxima of such multinary NCs between 700 and 800 nm, minimize their emission line widths (to below 40 nm), and maximize their photoluminescence quantum efficiencies (up to 89%) and phase/chemical stabilities. Detailed structural analysis revealed that the Cs x FA 1- x Pb(Br 1- y I y ) 3 NCs adopt a cubic perovskite structure of FAPbI 3 , with iodide anions partially substituted by bromide ions. Most importantly, we demonstrate the excellent transference of reaction
Genova, J; Decheva-Zarkova, M; Pavlič, J I
Giant lipid vesicles (liposomes) are the simplest model of the biological cell and can be easily formed from natural or synthetic lipid species with controlled composition and properties. This is the reason why they are the preferred objects for various scientific investigations. Amphotericin B (AmB) is a membrane active drug, used for treatment of systemic fungal infections. In this work we studied the morphological behavior of giant SOPC vesicles in asymmetrical presence of amphotericin B antibiotic in the vicinity of the lipid membrane. The visualization of the vesicles was carried out via inverted phase contrast microscopy. The illumination source was modified in a way that tungsten light bulb was replaced by 10 W white LED chip. All the experiments were performed using CellASIC ONIX Microfluidic Platform. The setup has been modified thus opening new opportunities for a variety of experimental realizations. The performed morphological studies showed strong and irreversible effect on the vesicle shape at the presence of amphotericin B in concentration 10 -5 g/l in the outer for the liposome's membrane solution. At concentration 10 -3 g/l AmB the effect was less visible and in 15-20 minutes the vesicles regained its initial spherical shape. (paper)
Xu, Yan; Zhang, Dong-Yang; Meng, Xiang-Yun; Liu, Xi; Sheng, Sheng; Wu, Guo-Hua; Wang, Jun; Wu, Fu-An
Today, continuous processing is regarded as an effective on-demand production technique of pharmaceuticals. Homemade microreactors packed with immobilized lipase under continuous-flow conditions were first applied to tailor the production of high-value caffeic acid phenethyl ester (CAPE) from methyl caffeate (MC) and 2-phenylethanol (PE) in cyclohexane via transesterification; however, this method is challenging due to the lack of a rapid platform for monitoring caffeates in microfluidic biocatalysis. The reactants were directly analyzed using Direct Analysis in Real Time Mass Spectrometry (DART-MS), and the corresponding ionization parameters were investigated. Special ions produced from MC (parent ion m/z 192.87 and product ion m/z 133.44) and CAPE (parent ion m/z 282.93 and product ion m/z 178.87) were determined using DART-MS 2 in the negative ion mode. The peak areas of the select reaction monitoring (SRM) signals were calculated to develop the standard curves for quantitative analyses of the concentration. Reasonable linear regression equations of MC and CAPE were obtained in the range of 3.125-50.000mg/L, with linear coefficients (R 2 ) of 0.9515 and 0.9973, limits of detection (LOD) of 0.005 and 0.003mg/L, limits of quantification (LOQ) of 0.02 and 0.01mg/L, and recovery ranges of 92.50-97.11% and 90.11-97.60%, respectively. The results using DART-MS 2 were in good agreement with those using conventional High-Performance Liquid Chromatography with a UV detector (HPLC-UV) and were successfully applied to monitor the kinetics constants and mass transfer coefficients in a continuous-flow packed bed microreactor. Thus, the DART-MS 2 method is an efficient tool for analyzing caffeates in microfluidic biocatalysis with limited sample preparation and short operating time. Copyright © 2017 Elsevier B.V. All rights reserved.
The advent of DNA sequencing technologies and the various applications that can be performed will have a dramatic effect on medicine and healthcare in the near future. There are several DNA sequencing platforms available on the market for research and clinical use. Based on the medical laboratory scientist or researcher's needs and taking into consideration laboratory space and budget, one can chose which platform will be beneficial to their institution and their patient population. Although some of the instrument costs seem high, diagnosing a patient quickly and accurately will save hospitals money with fewer hospital stays and targeted treatment based on an individual's genetic make-up. By determining the type of disease an individual has, based on the mutations present or having the ability to prescribe the appropriate antimicrobials based on the knowledge of the organism's resistance patterns, the clinician will be better able to treat and diagnose a patient which ultimately will improve patient outcomes and prognosis.
Cheng, Shi; Wu, Zhigang
Microfluidics, a field that has been well-established for several decades, has seen extensive applications in the areas of biology, chemistry, and medicine. However, it might be very hard to imagine how such soft microfluidic devices would be used in other areas, such as electronics, in which stiff, solid metals, insulators, and semiconductors have previously dominated. Very recently, things have radically changed. Taking advantage of native properties of microfluidics, advances in microfluidics-based electronics have shown great potential in numerous new appealing applications, e.g. bio-inspired devices, body-worn healthcare and medical sensing systems, and ergonomic units, in which conventional rigid, bulky electronics are facing insurmountable obstacles to fulfil the demand on comfortable user experience. Not only would the birth of microfluidic electronics contribute to both the microfluidics and electronics fields, but it may also shape the future of our daily life. Nevertheless, microfluidic electronics are still at a very early stage, and significant efforts in research and development are needed to advance this emerging field. The intention of this article is to review recent research outcomes in the field of microfluidic electronics, and address current technical challenges and issues. The outlook of future development in microfluidic electronic devices and systems, as well as new fabrication techniques, is also discussed. Moreover, the authors would like to inspire both the microfluidics and electronics communities to further exploit this newly-established field.
Full Text Available Microfluidic technology is the emerging technologies in researching fluid channel and related applications in the micro and nano-scale space. Microfluidic chip is a new miniaturized rapid analysis platform by microfluidic technology, it has many characteristics such as liquid flow control, minimal reagent consumption, rapid analysis, which is widely used in physics, chemistry, biology, and engineering science and other fields, it has strong interdisciplinary. This paper mainly discusses research progress of materials used for microfluidic chips and the devices based on microfluidic technology, including microfluidic chip, microfluidic optical devices, microfluidic laser preparation, microfluidic chip applications, focusing on the quasi-molecular laser processing technology and femtosecond laser processing technology in the microfluidic devices preparation, and make development prospects for it.
Electrowetting (EW)-based digital microfluidic systems (DMF) and droplet-based two-phase flow microfluidic systems (TPF) with closed channels are the most widely used microfluidic platforms. In general, these two approaches have been considered independently. However, integrating the two
Yao, Lu; Zhu, Li-Ping; Xu, Xiao-Yan; Tan, Ling-Ling; Sadilek, Martin; Fan, Huan; Hu, Bo; Shen, Xiao-Ting; Yang, Jie; Qiao, Bin; Yang, Song
Transcriptomic analysis of cultured fungi suggests that many genes for secondary metabolite synthesis are presumably silent under standard laboratory condition. In order to investigate the expression of silent genes in symbiotic systems, 136 fungi-fungi symbiotic systems were built up by co-culturing seventeen basidiomycetes, among which the co-culture of Trametes versicolor and Ganoderma applanatum demonstrated the strongest coloration of confrontation zones. Metabolomics study of this co-culture discovered that sixty-two features were either newly synthesized or highly produced in the co-culture compared with individual cultures. Molecular network analysis highlighted a subnetwork including two novel xylosides (compounds 2 and 3). Compound 2 was further identified as N-(4-methoxyphenyl)formamide 2-O-β-D-xyloside and was revealed to have the potential to enhance the cell viability of human immortalized bronchial epithelial cell line of Beas-2B. Moreover, bioinformatics and transcriptional analysis of T. versicolor revealed a potential candidate gene (GI: 636605689) encoding xylosyltransferases for xylosylation. Additionally, 3-phenyllactic acid and orsellinic acid were detected for the first time in G. applanatum, which may be ascribed to response against T.versicolor stress. In general, the described co-culture platform provides a powerful tool to discover novel metabolites and help gain insights into the mechanism of silent gene activation in fungal defense.
van den Berg, Albert; Segerink, Loes Irene
This book presents an overview of the major microfluidics techniques and platforms used for medicine and medical applications, providing the reader with an overview of the recent developments in this field. It is divided in three parts: (1) tissue and organs on-chip, (2) microfluidics for medicine
Gulati, Shelly; Rouilly, Vincent; Niu, Xize; Chappell, James; Kitney, Richard I.; Edel, Joshua B.; Freemont, Paul S.; deMello, Andrew J.
We introduce microfluidics technologies as a key foundational technology for synthetic biology experimentation. Recent advances in the field of microfluidics are reviewed and the potential of such a technological platform to support the rapid development of synthetic biology solutions is discussed.
Hassanzadeh-Barforoushi, Amin; Shemesh, Jonathan; Farbehi, Nona; Asadnia, Mohsen; Yeoh, Guan Heng; Harvey, Richard P.; Nordon, Robert E.; Warkiani, Majid Ebrahimi
Regulation of tissue development and repair depends on communication between neighbouring cells. Recent advances in cell micro-contact printing and microfluidics have facilitated the in-vitro study of homotypic and heterotypic cell-cell interaction. Nonetheless, these techniques are still complicated to perform and as a result, are seldom used by biologists. We report here development of a temporarily sealed microfluidic stamping device which utilizes a novel valve design for patterning two adherent cell lines with well-defined interlacing configurations to study cell-cell interactions. We demonstrate post-stamping cell viability of >95%, the stamping of multiple adherent cell types, and the ability to control the seeded cell density. We also show viability, proliferation and migration of cultured cells, enabling analysis of co-culture boundary conditions on cell fate. We also developed an in-vitro model of endothelial and cardiac stem cell interactions, which are thought to regulate coronary repair after myocardial injury. The stamp is fabricated using microfabrication techniques, is operated with a lab pipettor and uses very low reagent volumes of 20 μl with cell injection efficiency of >70%. This easy-to-use device provides a general strategy for micro-patterning of multiple cell types and will be important for studying cell-cell interactions in a multitude of applications.
Else M Vedula
Full Text Available In the kidney, the renal proximal tubule (PT reabsorbs solutes into the peritubular capillaries through active transport. Here, we replicate this reabsorptive function in vitro by engineering a microfluidic PT. The microfluidic PT architecture comprises a porous membrane with user-defined submicron surface topography separating two microchannels representing a PT filtrate lumen and a peritubular capillary lumen. Human PT epithelial cells and microvascular endothelial cells in respective microchannels created a PT-like reabsorptive barrier. Co-culturing epithelial and endothelial cells in the microfluidic architecture enhanced viability, metabolic activity, and compactness of the epithelial layer. The resulting tissue expressed tight junctions, kidney-specific morphology, and polarized expression of kidney markers. The microfluidic PT actively performed sodium-coupled glucose transport, which could be modulated by administration of a sodium-transport inhibiting drug. The microfluidic PT reproduces human physiology at the cellular and tissue levels, and measurable tissue function which can quantify kidney pharmaceutical efficacy and toxicity.
Terrasso, Ana Paula; Silva, Ana Carina; Filipe, Augusto; Pedroso, Pedro; Ferreira, Ana Lúcia; Alves, Paula Marques; Brito, Catarina
Central nervous system drug development has registered high attrition rates, mainly due to the lack of efficacy of drug candidates, highlighting the low reliability of the models used in early-stage drug development and the need for new in vitro human cell-based models and assays to accurately identify and validate drug candidates. 3D human cell models can include different tissue cell types and represent the spatiotemporal context of the original tissue (co-cultures), allowing the establishment of biologically-relevant cell-cell and cell-extracellular matrix interactions. Nevertheless, exploitation of these 3D models for neuroprotection assessment has been limited due to the lack of data to validate such 3D co-culture approaches. In this work we combined a 3D human neuron-astrocyte co-culture with a cell viability endpoint for the implementation of a novel in vitro neuroprotection assay, over an oxidative insult. Neuroprotection assay robustness and specificity, and the applicability of Presto Blue, MTT and CytoTox-Glo viability assays to the 3D co-culture were evaluated. Presto Blue was the adequate endpoint as it is non-destructive and is a simpler and reliable assay. Semi-automation of the cell viability endpoint was performed, indicating that the assay setup is amenable to be transferred to automated screening platforms. Finally, the neuroprotection assay setup was applied to a series of 36 test compounds and several candidates with higher neuroprotective effect than the positive control, Idebenone, were identified. The robustness and simplicity of the implemented neuroprotection assay with the cell viability endpoint enables the use of more complex and reliable 3D in vitro cell models to identify and validate drug candidates. Copyright © 2016 Elsevier Inc. All rights reserved.
A 3-D microfluidic system consisting of microchamber arrays embedded in a collagen hydrogel with tuneable biochemical gradients that mimics the tumour microenvironment of mammary glands was constructed for the investigation on the interactions between invasive breast cancer cells and stromal cells. The hollow microchambers in collagen provide a very similar 3-D environment to that in vivo that regulates collective cellular dynamics and behaviour, while the microfluidic channels surrounding the collagen microchamber arrays allow one to impose complex concentration gradients of specific biological molecules or drugs. We found that breast epithelial cells (MCF-10A) seeded in the microchambers formed lumen-like structures similar to those in epithelial layers. When MCF-10A cells were co-cultured with invasive breast cancer cells (MDA-MB-231), the formation of lumen-like structures in the microchambers was inhibited, indicating the capability of cancer cells to disrupt the structures formed by surrounding cells for further invasion and metastasis. Subsequent mechanism studies showed that down regulation of E-cad expression due to MMPs produced by the cancer cells plays a dominant role in determining the cellular behaviour. Our microfluidic system offers a robust platform for high throughput studies that aim to understand combinatorial effects of multiple biochemical and microenvironmental factors.
Smejkal, P.; Breadmore, M. C.; Guijt, R. M.; Foret, František; Bek, F.; Macka, M.
Roč. 803, NOV (2013), s. 135-142 ISSN 0003-2670 R&D Projects: GA ČR(CZ) GAP301/11/2055 Institutional support: RVO:68081715 Keywords : isotachophoresis * microfluidics * fluorescence * indirect detection * serum Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.517, year: 2013
Bossi, A M [Department of Biotechnology, University of Verona, Strada Le Grazie 15, I-37134, Verona (Italy); Vareijka, M; Piletska, E V; Turner, A P F; Piletsky, S A [Cranfield Health, Cranfield University, Vincent Building B52, Cranfield, Bedfordshire, MK43 0AL (United Kingdom); Meglinski, I [Department of Physics, University of Otago, PO Box 56, Dunedin, 9054 (New Zealand)
Microfluidic devices find many applications in biotechnologies. Here, we introduce a flexible and biocompatible microfluidic ice-based platform with tunable parameters and configuration of microfluidic patterns that can be changed multiple times during experiments. Freezing and melting of cavities, channels and complex relief structures created and maintained in the bulk of ice by continuous scanning of an infrared laser beam are used as a valve action in microfluidic systems. We demonstrate that pre-concentration of samples and transport of ions and dyes through the open channels created can be achieved in ice microfluidic patterns by IR laser-assisted zone melting. The proposed approach can be useful for performing separation and sensing processes in flexible reconfigurable microfluidic devices. (paper)
Bossi, A M; Vareijka, M; Piletska, E V; Turner, A P F; Piletsky, S A; Meglinski, I
Microfluidic devices find many applications in biotechnologies. Here, we introduce a flexible and biocompatible microfluidic ice-based platform with tunable parameters and configuration of microfluidic patterns that can be changed multiple times during experiments. Freezing and melting of cavities, channels and complex relief structures created and maintained in the bulk of ice by continuous scanning of an infrared laser beam are used as a valve action in microfluidic systems. We demonstrate that pre-concentration of samples and transport of ions and dyes through the open channels created can be achieved in ice microfluidic patterns by IR laser-assisted zone melting. The proposed approach can be useful for performing separation and sensing processes in flexible reconfigurable microfluidic devices. (paper)
Bossi, A. M.; Vareijka, M.; Piletska, E. V.; Turner, A. P. F.; Meglinski, I.; Piletsky, S. A.
Microfluidic devices find many applications in biotechnologies. Here, we introduce a flexible and biocompatible microfluidic ice-based platform with tunable parameters and configuration of microfluidic patterns that can be changed multiple times during experiments. Freezing and melting of cavities, channels and complex relief structures created and maintained in the bulk of ice by continuous scanning of an infrared laser beam are used as a valve action in microfluidic systems. We demonstrate that pre-concentration of samples and transport of ions and dyes through the open channels created can be achieved in ice microfluidic patterns by IR laser-assisted zone melting. The proposed approach can be useful for performing separation and sensing processes in flexible reconfigurable microfluidic devices.
Datta, Proyag; Hammacher, Jens; Pease, Mark; Gurung, Sitanshu; Goettert, Jost
Microfluidic is a field of considerable interest. While significant research has been carried out to develop microfluidic components, very little has been done to integrate the components into a complete working system. We present a flexible modular system platform that addresses the requirements of a complete microfluidic system. A microfluidic stack system is demonstrated with the layers of the stack being modular for specific functions. The stack and accompanying infrastructure provides an attractive platform for users to transition their design concepts into a working microfluidic system quickly with very little effort. The concept is demonstrated by using the system to carry out a chemilumiscence experiment. Details regarding the fabrication, assembly and experimental methods are presented
Misun, Patrick M; Birchler, Axel K; Lang, Moritz; Hierlemann, Andreas; Frey, Olivier
The hanging-drop network (HDN) is a technology platform based on a completely open microfluidic network at the bottom of an inverted, surface-patterned substrate. The platform is predominantly used for the formation, culturing, and interaction of self-assembled spherical microtissues (spheroids) under precisely controlled flow conditions. Here, we describe design, fabrication, and operation of microfluidic hanging-drop networks.
Lafleur, Josiane P.; Snakenborg, Detlef; Møller, M.
Research on the structure of proteins can bring forth a wealth of information about biological function and can be used to better understand the processes in living cells. This paper reports a new microfluidic sample preparation system for the structural investigation of proteins by Small Angle X......-ray Scattering (SAXS). The system includes hardware and software features for precise fluidic control, synchrotron beamline control, UV absorbance measurements and automated data analysis. The precise fluidic handling capabilities are used to transport and precisely position samples as small as 500 n...
Lafleur, Josiane P.; Snakenborg, Detlef; Nielsen, Søren Skou
A new microfluidic sample-preparation system is presented for the structural investigation of proteins using small-angle X-ray scattering (SAXS) at synchrotrons. The system includes hardware and software features for precise fluidic control, sample mixing by diffusion, automated X-ray exposure...... control, UV absorbance measurements and automated data analysis. As little as 15 l of sample is required to perform a complete analysis cycle, including sample mixing, SAXS measurement, continuous UV absorbance measurements, and cleaning of the channels and X-ray cell with buffer. The complete analysis...
Microfluidics is a young and rapidly expanding scientific discipline, which deals with fluids and solutions in miniaturized systems, the so-called lab-on-a-chip systems. It has applications in chemical engineering, pharmaceutics, biotechnology and medicine. As the lab-on-a-chip systems grow...
Mark, Daniel; von Stetten, Felix; Zengerle, Roland
Within the last decade a huge increase in research activity in microfluidics could be observed. However, despite several commercial success stories, microfluidic chips are still not sold in high numbers in mass markets so far. Here we promote a new concept that could be an alternative approach to commercialization: designing microfluidic chips for existing off-the-shelf instruments. Such "Microfluidic Apps" could significantly lower market entry barriers and provide many advantages: developers of microfluidic chips make use of existing equipment or platforms and do not have to develop instruments from scratch; end-users can profit from microfluidics without the need to invest in new equipment; instrument manufacturers benefit from an expanded customer base due to the new applications that can be implemented in their instruments. Microfluidic Apps could be considered as low-cost disposables which can easily be distributed globally via web-shops. Therefore they could be a door-opener for high-volume mass markets.
David, Manu S; Kelly, Elizabeth; Zoellner, Hans
We recently reported exchange of membrane and cytoplasm during contact co-culture between human Gingival Fibroblasts (h-GF) and SAOS-2 osteosarcoma cells, a process we termed 'cellular sipping' to reflect the manner in which cells become morphologically diverse through uptake of material from the opposing cell type, independent of genetic change. Cellular sipping is increased by Tumor Necrosis Factor-α (TNF-α), and we here show for the first time altered cytokine synthesis in contact co-culture supporting cellular sipping compared with co-culture where h-GF and SAOS-2 were separated in transwells. SAOS-2 had often undetectably low cytokine levels, while Interleukin-6 (IL-6), Granulocyte Colony Stimulating Factor (G-CSF) and Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) were secreted primarily by TNF-α stimulated h-GF and basic Fibroblast Growth Factor (FGF) was prominent in h-GF lysates (p cultures permitting cellular sipping had lower IL-6, G-CSF and GM-CSF levels, as well as higher lysate FGF levels compared with TNF-α treated h-GF alone (p cultures in transwells, with increased IL-6, G-CSF and GM-CSF levels (p cultures where cellular sipping occurs, potentially contributing to tumor inflammatory responses. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.
Tai, Yu-Chong (Inventor); Zheng, Siyang (Inventor); Lin, Jeffrey Chun-Hui (Inventor); Kasdan, Harvey L. (Inventor)
Described herein are particular embodiments relating to a microfluidic device that may be utilized for cell sensing, counting, and/or sorting. Particular aspects relate to a microfabricated device that is capable of differentiating single cell types from dense cell populations. One particular embodiment relates a device and methods of using the same for sensing, counting, and/or sorting leukocytes from whole, undiluted blood samples.
Lignos, Ioannis; Protesescu, Loredana; Emiroglu, Dilara Börte; Maceiczyk, Richard; Schneider, Simon; Kovalenko, Maksym V; deMello, Andrew J
Hybrid organic-inorganic perovskites and in particular formamidinium lead halide (FAPbX 3 , X = Cl, Br, I) perovskite nanocrystals (NCs) have shown great promise for their implementation in optoelectronic devices. Specifically, the Br and I counterparts have shown unprecedented photoluminescence properties, including precise wavelength tuning (530-790 nm), narrow emission linewidths (photoluminescence quantum yields (70-90%). However, the controlled formation of blue emitting FAPb(Cl 1-x Br x ) 3 NCs lags behind their green and red counterparts and the mechanism of their formation remains unclear. Herein, we report the formation of FAPb(Cl 1-x Br x ) 3 NCs with stable emission between 440 and 520 nm in a fully automated droplet-based microfluidic reactor and subsequent reaction upscaling in conventional laboratory glassware. The thorough parametric screening allows for the elucidation of parametric zones (FA-to-Pb and Br-to-Cl molar ratios, temperature, and excess oleic acid) for the formation of nanoplatelets and/or NCs. In contrast to CsPb(Cl 1-x Br x ) 3 NCs, based on online parametric screening and offline structural characterization, we demonstrate that the controlled synthesis of Cl-rich perovskites (above 60 at% Cl) with stable emission remains a challenge due to fast segregation of halide ions.
Fernandes, Ana C.; Petersen, Benjamin; Møller, Lars
for rapidenzyme inactivation. The thermal inactivation platform developed is compared with a standard benchtop ThermoMixer in terms of inactivation efficiency for glucose oxidase and catalase. A higher activity loss was observed for enzyme inactivation under flow conditions (inactivation achieved at 120 s...
Fan, Beiyuan; Li, Xiufeng; Chen, Deyong; Peng, Hongshang; Wang, Junbo; Chen, Jian
This article reviews recent developments in microfluidic systems enabling high-throughput characterization of single-cell proteins. Four key perspectives of microfluidic platforms are included in this review: (1) microfluidic fluorescent flow cytometry; (2) droplet based microfluidic flow cytometry; (3) large-array micro wells (microengraving); and (4) large-array micro chambers (barcode microchips). We examine the advantages and limitations of each technique and discuss future research oppor...
Benett, William J.; Krulevitch, Peter A.
A miniature connector for introducing microliter quantities of solutions into microfabricated fluidic devices. The fluidic connector, for example, joins standard high pressure liquid chromatography (HPLC) tubing to 1 mm diameter holes in silicon or glass, enabling ml-sized volumes of sample solutions to be merged with .mu.l-sized devices. The connector has many features, including ease of connect and disconnect; a small footprint which enables numerous connectors to be located in a small area; low dead volume; helium leak-tight; and tubing does not twist during connection. Thus the connector enables easy and effective change of microfluidic devices and introduction of different solutions in the devices.
Mohammadi, Mohammad Hossein; Heidary Araghi, Behnaz; Beydaghi, Vahid; Geraili, Armin; Moradi, Farshid; Jafari, Parya; Janmaleki, Mohsen; Valente, Karolina Papera; Akbari, Mohsen; Sanati-Nezhad, Amir
In recent years, both tissue engineering and microfluidics have significantly contributed in engineering of in vitro skin substitutes to test the penetration of chemicals or to replace damaged skins. Organ-on-chip platforms have been recently inspired by the integration of microfluidics and biomaterials in order to develop physiologically relevant disease models. However, the application of organ-on-chip on the development of skin disease models is still limited and needs to be further developed. The impact of tissue engineering, biomaterials and microfluidic platforms on the development of skin grafts and biomimetic in vitro skin models is reviewed. The integration of tissue engineering and microfluidics for the development of biomimetic skin-on-chip platforms is further discussed, not only to improve the performance of present skin models, but also for the development of novel skin disease platforms for drug screening processes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Boyd-Moss, Mitchell; Baratchi, Sara; Di Venere, Martina; Khoshmanesh, Khashayar
Microfluidic systems enable rapid diagnosis, screening and monitoring of diseases and health conditions using small amounts of biological samples and reagents. Despite these remarkable features, conventional microfluidic systems rely on bulky expensive external equipment, which hinders their utility as powerful analysis tools outside of research laboratories. 'Self-contained' microfluidic systems, which contain all necessary components to facilitate a complete assay, have been developed to address this limitation. In this review, we provide an in-depth overview of self-contained microfluidic systems. We categorise these systems based on their operating mechanisms into three major groups: passive, hand-powered and active. Several examples are provided to discuss the structure, capabilities and shortcomings of each group. In particular, we discuss the self-contained microfluidic systems enabled by active mechanisms, due to their unique capability for running multi-step and highly controllable diagnostic assays. Integration of self-contained microfluidic systems with the image acquisition and processing capabilities of smartphones, especially those equipped with accessory optical components, enables highly sensitive and quantitative assays, which are discussed. Finally, the future trends and possible solutions to expand the versatility of self-contained, stand-alone microfluidic platforms are outlined.
Moen, Scott T.; Hatcher, Christopher L.; Singh, Anup K.
We present a miniaturized centrifugal platform that uses density centrifugation for separation and analysis of biological components in small volume samples (~5 μL). We demonstrate the ability to enrich leukocytes for on-disk visualization via microscopy, as well as recovery of viable cells from each of the gradient partitions. In addition, we simplified the traditional Modified Wright-Giemsa staining by decreasing the time, volume, and expertise involved in the procedure. From a whole blood sample, we were able to extract 95.15% of leukocytes while excluding 99.8% of red blood cells. This platform has great potential in both medical diagnostics and research applications as it offers a simpler, automated, and inexpensive method for biological sample separation, analysis, and downstream culturing. PMID:27054764
Freyer, Nora; Greuel, Selina; Knöspel, Fanny; Strahl, Nadja; Amini, Leila; Jacobs, Frank; Monshouwer, Mario; Zeilinger, Katrin
The derivation of hepatocytes from human induced pluripotent stem cells (hiPSC) is of great interest for applications in pharmacological research. However, full maturation of hiPSC-derived hepatocytes has not yet been achieved in vitro. To improve hepatic differentiation, co-cultivation of hiPSC with human umbilical vein endothelial cells (HUVEC) during hepatic differentiation was investigated in this study. In the first step, different culture media variations based on hepatocyte culture medium (HCM) were tested in HUVEC mono-cultures to establish a suitable culture medium for co-culture experiments. Based on the results, two media variants were selected to differentiate hiPSC-derived definitive endodermal (DE) cells into mature hepatocytes with or without HUVEC addition. DE cells differentiated in mono-cultures in the presence of those media variants showed a significant increase ( p < 0.05) in secretion of α-fetoprotein and in activities of cytochrome P450 (CYP) isoenzymes CYP2B6 and CYP3A4 as compared with cells differentiated in unmodified HCM used as control. Co-cultivation with HUVEC did not further improve the differentiation outcome. Thus, it can be concluded that the effect of the used medium outweighed the effect of HUVEC co-culture, emphasizing the importance of the culture medium composition for hiPSC differentiation.
Full Text Available The recent emergence of antimicrobial resistance has become a major concern for worldwide policy makers as very few new antibiotics have been developed in the last twenty-five years. To prevent the death of millions of people worldwide, there is an urgent need for a cheap, fast and accurate set of tools and techniques that can help to discover and develop new antimicrobial drugs. In the past decade, microfluidic platforms have emerged as potential systems for conducting pharmacological studies. Recent studies have demonstrated that microfluidic platforms can perform rapid antibiotic susceptibility tests to evaluate antimicrobial drugs’ efficacy. In addition, the development of cell-on-a-chip and organ-on-a-chip platforms have enabled the early drug testing, providing more accurate insights into conventional cell cultures on the drug pharmacokinetics and toxicity, at the early and cheaper stage of drug development, i.e., prior to animal and human testing. In this review, we focus on the recent developments of microfluidic platforms for rapid antibiotics susceptibility testing, investigating bacterial persistence and non-growing but metabolically active (NGMA bacteria, evaluating antibiotic effectiveness on biofilms and combinatorial effect of antibiotics, as well as microfluidic platforms that can be used for in vitro antibiotic toxicity testing.
Yildiz-Ozturk, Ece; Yesil-Celiktas, Ozlem
Biomicrofluidics is an emerging field at the cross roads of microfluidics and life sciences which requires intensive research efforts in terms of introducing appropriate designs, production techniques, and analysis. The ultimate goal is to deliver innovative and cost-effective microfluidic devices to biotech, biomedical, and pharmaceutical industries. Therefore, creating an in-depth understanding of the transport phenomena of cells and biomolecules becomes vital and concurrently poses significant challenges. The present article outlines the recent advancements in diffusion phenomena of cells and biomolecules by highlighting transport principles from an engineering perspective, cell responses in microfluidic devices with emphases on diffusion- and flow-based microfluidic gradient platforms, macroscopic and microscopic approaches for investigating the diffusion phenomena of biomolecules, microfluidic platforms for the delivery of these molecules, as well as the state of the art in biological applications of mammalian cell responses and diffusion of biomolecules.
Khandurina, Julia; Guttman, András
Microfabricated bioanalytical devices (also referred to as laboratory-on-a-chip or micro-TAS) offer highly efficient platforms for simultaneous analysis of a large number of biologically important molecules, possessing great potential for genome, proteome and metabolome studies. Development and implementation of microfluidic-based bioanalytical tools involves both established and evolving technologies, including microlithography, micromachining, micro-electromechanical systems technology and nanotechnology. This article provides an overview of the latest developments in the key device subject areas and the basic interdisciplinary technologies. Important aspects of DNA and protein analysis, interfacing issues and system integration are all thoroughly discussed, along with applications for this novel "synergized" technology in high-throughput separations of biologically important molecules. This review also gives a better understanding of how to utilize these technologies as well as to provide appropriate technical solutions to problems perceived as being more fundamental.
Pollack, Michael G.; Srinivasan, Vijay; Eckhardt, Allen; Paik, Philip Y.; Sudarsan, Arjun; Shenderov, Alex; Hua, Zhishan; Pamula, Vamsee K.
Three innovations address the needs of the medical world with regard to microfluidic manipulation and testing of physiological samples in ways that can benefit point-of-care needs for patients such as premature infants, for which drawing of blood for continuous tests can be life-threatening in their own right, and for expedited results. A chip with sample injection elements, reservoirs (and waste), droplet formation structures, fluidic pathways, mixing areas, and optical detection sites, was fabricated to test the various components of the microfluidic platform, both individually and in integrated fashion. The droplet control system permits a user to control droplet microactuator system functions, such as droplet operations and detector operations. Also, the programming system allows a user to develop software routines for controlling droplet microactuator system functions, such as droplet operations and detector operations. A chip is incorporated into the system with a controller, a detector, input and output devices, and software. A novel filler fluid formulation is used for the transport of droplets with high protein concentrations. Novel assemblies for detection of photons from an on-chip droplet are present, as well as novel systems for conducting various assays, such as immunoassays and PCR (polymerase chain reaction). The lab-on-a-chip (a.k.a., lab-on-a-printed-circuit board) processes physiological samples and comprises a system for automated, multi-analyte measurements using sub-microliter samples of human serum. The invention also relates to a diagnostic chip and system including the chip that performs many of the routine operations of a central labbased chemistry analyzer, integrating, for example, colorimetric assays (e.g., for proteins), chemiluminescence/fluorescence assays (e.g., for enzymes, electrolytes, and gases), and/or conductometric assays (e.g., for hematocrit on plasma and whole blood) on a single chip platform.
Fernandes, Ana C; Gernaey, Krist V; Krühne, Ulrich
From its birth, microfluidics has been referenced as a revolutionary technology and the solution to long standing technological and sociological issues, such as detection of dilute compounds and personalized healthcare. Microfluidics has for example been envisioned as: (1) being capable of miniaturizing industrial production plants, thereby increasing their automation and operational safety at low cost; (2) being able to identify rare diseases by running bioanalytics directly on the patient's skin; (3) allowing health diagnostics in point-of-care sites through cheap lab-on-a-chip devices. However, the current state of microfluidics, although technologically advanced, has so far failed to reach the originally promised widespread use. In this paper, some of the aspects are identified and discussed that have prevented microfluidics from reaching its full potential, especially in the chemical engineering and biotechnology fields, focusing mainly on the specialization on a single target of most microfluidic devices and offering a perspective on the alternate, multi-use, "plug and play" approach. Increasing the flexibility of microfluidic platforms, by increasing their compatibility with different substrates, reactions and operation conditions, and other microfluidic systems is indeed of surmount importance and current academic and industrial approaches to modular microfluidics are presented. Furthermore, two views on the commercialization of plug-and-play microfluidics systems, leading towards improved acceptance and more widespread use, are introduced. A brief review of the main materials and fabrication strategies used in these fields, is also presented. Finally, a step-wise guide towards the development of microfluidic systems is introduced with special focus on the integration of sensors in microfluidics. The proposed guidelines are then applied for the development of two different example platforms, and to three examples taken from literature. With this work, we
, Uhlmann et al and articles to be published in a later issue by Bäumchen and Jacobs, Walz et al). Moreover, simulations accounted for these new phenomena (see articles in this issue by Leonforte et al, Hyväaluoma et al, Varnik et al, Chelakkot et al, Litvinov et al and the article to be published in a later issue by Boettcher et al), since commercial software packages typically override these special yet fundamentally new conditions. For future applications, the know-how can be used, for instance, to manipulate particles or molecules in microfluidic systems (see articles in this issue by Nottebrock et al, Straube, Uhlmann et al and the article to be published in a later issue by Boettcher et al). The articles have been divided into four subsections: 'Probing the boundary condition', 'Flow over or in special geometries', 'Soft objects in fluid flow' and 'Manipulating flow'. Many articles, however, cover more than only one aspect and could easily be listed under one of the other subsections. Three articles, two listed in the section 'Probing the boundary condition' and one listed in 'Manipulating flow', could not be included and will be published in a later issue (Bäumchen and Jacobs, Walz et al, Boettcher et al). The collection of studies gives a comprehensive overview of what has been achieved to 'bridge the gap between molecular motion and continuum flow', which was the mission of the programme and which will now form a sound platform for continuative studies. References  Bowtell D D 1999 Nature Genet. 21 25  Lion N et al 2003 Electrophoresis 24 3533  Weston A D and Hood L 2004 J. Proteome Res. 3 179  Li D 2004 Microfluidics Nanofluidics 1 1 Nano- and microfluidics contents Impact of slippage on the morphology and stability of a dewetting rim Andreas Münch and Barbara Wagner Nanoscale discontinuities at the boundary of flowing liquids: a look into structure Max Wolff, Philipp Gutfreund, Adrian Rühm, Bulent Akgun and Hartmut Zabel Capillary waves of
Krühne, Ulrich; Heintz, Søren; Ringborg, Rolf Hoffmeyer
The increasing interest in biocatalytic processes means there is a clear need for a new systematic development paradigm which encompasses both protein engineering and process engineering. This paper argues that through the use of a new microfluidic platform, data can be collected more rapidly...
Mou, Lei; Jiang, Xingyu
Conventional immunoassays suffer from at least one of these following limitations: long processing time, high costs, poor user-friendliness, technical complexity, poor sensitivity and specificity. Microfluidics, a technology characterized by the engineered manipulation of fluids in channels with characteristic lengthscale of tens of micrometers, has shown considerable promise for improving immunoassays that could overcome these limitations in medical diagnostics and biology research. The combination of microfluidics and immunoassay can detect biomarkers with faster assay time, reduced volumes of reagents, lower power requirements, and higher levels of integration and automation compared to traditional approaches. This review focuses on the materials-related aspects of the recent advances in microfluidics-based immunoassays for point-of-care (POC) diagnostics of biomarkers. We compare the materials for microfluidic chips fabrication in five aspects: fabrication, integration, function, modification and cost, and describe their advantages and drawbacks. In addition, we review materials for modifying antibodies to improve the performance of the reaction of immunoassay. We also review the state of the art in microfluidic immunoassays POC platforms, from the laboratory to routine clinical practice, and also commercial products in the market. Finally, we discuss the current challenges and future developments in microfluidic immunoassays. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Yang, Hui; Gijs, Martin A M
This critical review summarizes the developments in the integration of micro-optical elements with microfluidic platforms for facilitating detection and automation of bio-analytical applications. Micro-optical elements, made by a variety of microfabrication techniques, advantageously contribute to the performance of an analytical system, especially when the latter has microfluidic features. Indeed the easy integration of optical control and detection modules with microfluidic technology helps to bridge the gap between the macroscopic world and chip-based analysis, paving the way for automated and high-throughput applications. In our review, we start the discussion with an introduction of microfluidic systems and micro-optical components, as well as aspects of their integration. We continue with a detailed description of different microfluidic and micro-optics technologies and their applications, with an emphasis on the realization of optical waveguides and microlenses. The review continues with specific sections highlighting the advantages of integrated micro-optical components in microfluidic systems for tackling a variety of analytical problems, like cytometry, nucleic acid and protein detection, cell biology, and chemical analysis applications.
Muniesh Muthaiyan Shanmugam
Full Text Available The study of model organisms is very important in view of their potential for application to human therapeutic uses. One such model organism is the nematode worm, Caenorhabditis elegans. As a nematode, C. elegans have ~65% similarity with human disease genes and, therefore, studies on C. elegans can be translated to human, as well as, C. elegans can be used in the study of different types of parasitic worms that infect other living organisms. In the past decade, many efforts have been undertaken to establish interdisciplinary research collaborations between biologists, physicists and engineers in order to develop microfluidic devices to study the biology of C. elegans. Microfluidic devices with the power to manipulate and detect bio-samples, regents or biomolecules in micro-scale environments can well fulfill the requirement to handle worms under proper laboratory conditions, thereby significantly increasing research productivity and knowledge. The recent development of different kinds of microfluidic devices with ultra-high throughput platforms has enabled researchers to carry out worm population studies. Microfluidic devices primarily comprises of chambers, channels and valves, wherein worms can be cultured, immobilized, imaged, etc. Microfluidic devices have been adapted to study various worm behaviors, including that deepen our understanding of neuromuscular connectivity and functions. This review will provide a clear account of the vital involvement of microfluidic devices in worm biology.
Bunge, Frank; Driesche, Sander van den; Vellekoop, Michael J
Lab-on-a-Chip (LoC) applications for the long-term analysis of mammalian cells are still very rare due to the lack of convenient cell cultivation devices. The difficulties are the integration of suitable supply structures, the need of expensive equipment like an incubator and sophisticated pumps as well as the choice of material. The presented device is made out of hard, but non-cytotoxic materials (silicon and glass) and contains two vertical arranged membranes out of hydrogel. The porous membranes are used to separate the culture chamber from two supply channels for gases and nutrients. The cells are fed continuously by diffusion through the membranes without the need of an incubator and low requirements on the supply of medium to the assembly. The diffusion of oxygen is modelled in order to find the optimal dimensions of the chamber. The chip is connected via 3D-printed holders to the macroscopic world. The holders are coated with Parlyene C to ensure that only biocompatible materials are in contact with the culture medium. The experiments with MDCK-cells show the successful seeding inside the chip, culturing and passaging. Consequently, the presented platform is a step towards Lab-on-a-Chip applications that require long-term cultivation of mammalian cells.
Quake, Stephen R; Marcus, Joshua S; Hansen, Carl L
Sieve valves for use in microfluidic device are provided. The valves are useful for impeding the flow of particles, such as chromatography beads or cells, in a microfluidic channel while allowing liquid solution to pass through the valve. The valves find particular use in making microfluidic chromatography modules.
Kristensen, Anders; Balslev, Søren; Gersborg-Hansen, Morten
A technology for miniaturized, polymer based lasers, suitable for integration with planar waveguides and microfluidic networks is presented. The microfluidic dye laser device consists of a microfluidic channel with an embedded optical resonator. The devices are fabricated in a thin polymer film...
Courses: Intercultural Communication, Interracial Communication, or an Interpersonal Communication class that covers co-cultural theory. Objectives: Students will be able to demonstrate a practical application of co-cultural theory by creating scenes that illustrate different communicative approaches and desired outcomes based on communication…
Zhu, L.; Sniadecki, N.; DeVoe, D. L.; Beamesderfer, M.; Semancik, S.; DeVoe, D. L.
A silicon-based microhotplate tin oxide (SnO2) gas sensor integrated into a polymer-based microfluidic system for monitoring of contaminants in water systems is presented. This device is designed to sample a water source, control the sample vapor pressure within a microchannel using integrated resistive heaters, and direct the vapor past the integrated gas sensor for analysis. The sensor platform takes advantage of novel technology allowing direct integration of discrete silicon chips into a larger polymer microfluidic substrate, including seamless fluidic and electrical interconnects between the substrate and silicon chip.
Sommer, Gregory Jon; Tentori, Augusto M.; Schaff, Ulrich Y.
We present a method for counting white blood cells that is uniquely compatible with centrifugation based microfluidics. Blood is deposited on top of one or more layers of density media within a microfluidic disk. Spinning the disk causes the cell populations within whole blood to settle through the media, reaching an equilibrium based on the density of each cell type. Separation and fluorescence measurement of cell types stained with a DNA dye is demonstrated using this technique. The integrated signal from bands of fluorescent microspheres is shown to be proportional to their initial concentration in suspension. Among the current generation of medical diagnostics are devices based on the principle of centrifuging a CD sized disk functionalized with microfluidics. These portable 'lab on a disk' devices are capable of conducting multiple assays directly from a blood sample, embodied by platforms developed by Gyros, Samsung, and Abaxis. [1,2] However, no centrifugal platform to date includes a differential white blood cell count, which is an important metric complimentary to diagnostic assays. Measuring the differential white blood cell count (the relative fraction of granulocytes, lymphocytes, and monocytes) is a standard medical diagnostic technique useful for identifying sepsis, leukemia, AIDS, radiation exposure, and a host of other conditions that affect the immune system. Several methods exist for measuring the relative white blood cell count including flow cytometry, electrical impedance, and visual identification from a stained drop of blood under a microscope. However, none of these methods is easily incorporated into a centrifugal microfluidic diagnostic platform.
Battiston, Kyle G; Cheung, Jane W C; Jain, Devika; Santerre, J Paul
Most natural tissues consist of multi-cellular systems made up of two or more cell types. However, some of these tissues may not regenerate themselves following tissue injury or disease without some form of intervention, such as from the use of tissue engineered constructs. Recent studies have increasingly used co-cultures in tissue engineering applications as these systems better model the natural tissues, both physically and biologically. This review aims to identify the challenges of using co-culture systems and to highlight different approaches with respect to the use of biomaterials in the use of such systems. The application of co-culture systems to stimulate a desired biological response and examples of studies within particular tissue engineering disciplines are summarized. A description of different analytical co-culture systems is also discussed and the role of biomaterials in the future of co-culture research are elaborated on. Understanding the complex cell-cell and cell-biomaterial interactions involved in co-culture systems will ultimately lead the field towards biomaterial concepts and designs with specific biochemical, electrical, and mechanical characteristics that are tailored towards the needs of distinct co-culture systems. Copyright © 2014 Elsevier Ltd. All rights reserved.
Van Dam, R. Michael; Shah, Gaurav; Keng, Pei-Yuin
The present disclosure sets forth incorporating microfluidic chips interfaces for use with digital microfluidic processes. Methods and devices according to the present disclosure utilize compact, integrated platforms that interface with a chip upstream and downstream of the reaction, as well as between intermediate reaction steps if needed. In some embodiments these interfaces are automated, including automation of a multiple reagent process. Various reagent delivery systems and methods are also disclosed.
possibilities for, for example, precise control of the chemical environment, 3D cultures, controlled co-culture of different cell types or automated, individual control of up to 96 cell culture chambers in one integrated system. Despite the great new opportunities to perform novel experimental designs......Microfluidic cell culture has been a research area with great attention the last decade due to its potential to mimic the in vivo cellular environment more closely compared to what is possible by conventional cell culture methods. Many exciting and complex devices have been presented providing......, these devices still lack general implementation into biological research laboratories. In this project, the usability and applicability of microfluidic cell culture systems have been investigated. The tested systems display good properties regarding optics and compatibility with standard laboratory equipment...
Full Text Available for microfluidics K. LAND, S. HUGO, M MBANJWA, L FOURIE CSIR Materials Science and Manufacturing P O Box 395, Pretoria 0001, SOUTH AFRICA Email: firstname.lastname@example.org INTRODUCTION Microfluidics refers to the manipulation of very small volumes of fluid.... Microfluidics is at the forefront of developing solutions for drug discovery, diagnostics (from glucose tests to malaria and TB testing) and environmental diagnostics (E-coli monitoring of drinking water). In order to quickly implement new designs, a rapid...
Volpatti, Lisa R; Yetisen, Ali K
Microfluidic devices offer automation and high-throughput screening, and operate at low volumes of consumables. Although microfluidics has the potential to reduce turnaround times and costs for analytical devices, particularly in medical, veterinary, and environmental sciences, this enabling technology has had limited diffusion into consumer products. This article analyzes the microfluidics market, identifies issues, and highlights successful commercialization strategies. Addressing niche markets and establishing compatibility with existing workflows will accelerate market penetration. Copyright © 2014 Elsevier Ltd. All rights reserved.
Kompella, Uday B.; Damiati, Safa A.
Microfluidic devices present unique advantages for the development of efficient drug carrier particles, cell-free protein synthesis systems, and rapid techniques for direct drug screening. Compared to bulk methods, by efficiently controlling the geometries of the fabricated chip and the flow rates of multiphase fluids, microfluidic technology enables the generation of highly stable, uniform, monodispersed particles with higher encapsulation efficiency. Since the existing preclinical models are inefficient drug screens for predicting clinical outcomes, microfluidic platforms might offer a more rapid and cost-effective alternative. Compared to 2D cell culture systems and in vivo animal models, microfluidic 3D platforms mimic the in vivo cell systems in a simple, inexpensive manner, which allows high throughput and multiplexed drug screening at the cell, organ, and whole-body levels. In this review, the generation of appropriate drug or gene carriers including different particle types using different configurations of microfluidic devices is highlighted. Additionally, this paper discusses the emergence of fabricated microfluidic cell-free protein synthesis systems for potential use at point of care as well as cell-, organ-, and human-on-a-chip models as smart, sensitive, and reproducible platforms, allowing the investigation of the effects of drugs under conditions imitating the biological system. PMID:29462948
Olsen, Brian Bilenberg; Helbo, Bjarne; Kutter, Jörg Peter
We present a tunable microfluidic dye laser fabricated in SU-8. The tunability is enabled by integrating a microfluidic diffusion mixer with an existing microfluidic dye laser design by Helbo et al. By controlling the relative flows in the mixer between a dye solution and a solvent......, the concentration of dye in the laser cavity can be adjusted, allowing the wavelength to be tuned. Wavelength tuning controlled by the dye concentration was demonstrated with macroscopic dye lasers already in 1971, but this principle only becomes practically applicable by the use of microfluidic mixing...
Dec 9, 2009 ... in co-cultures of human colon carcinoma cell spheroids obtained from different grades of ...... of adherens junction in prostate epithelial cells; Exp. Cell. Res. ... tumour-associated antigens is related to estrogen receptor status;.
Yudina, N Yu; Arlyapov, V A; Chepurnova, M A; Alferov, S V; Reshetilov, A N
Artificial microbial co-cultures were formed to develop the receptor element of a biosensor for assessment of biological oxygen demand (BOD). The co-cultures possessed broad substrate specificities and enabled assays of water and fermentation products within a broad BOD range (2.4-80 mg/dm(3)) with a high correlation to the standard method (R = 0.9988). The use of the co-cultures of the yeasts Pichia angusta, Arxula adeninivorans and Debaryomyces hansenii immobilized in N-vinylpyrrolidone-modified poly(vinyl alcohol) enabled developing a BOD biosensor possessing the characteristics not inferior to those in the known biosensors. The results are indicative of a potential of using these co-cultures as the receptor element base in prototype models of instruments for broad application. Copyright © 2015 Elsevier Inc. All rights reserved.
Full Text Available To investigate whether adipose-derived stem cells (ADSCs could be subject to neural differentiation induced only by Schwann cell (SC factors, we co-cultured ADSCs and SCs in transwell culture dishes. Immunoassaying, Western blot analysis, and RT-PCR were performed (1, 3, 7, 14 d and the co-cultured ADSCs showed gene and protein expression of S-100, Nestin, and GFAP. Further, qRT-PCR disclosed relative quantitative differences in the above three gene expressions. We think ADSCs can undergo induced neural differentiation by being co-cultured with SCs, and such differentiations begin 1 day after co-culture, become apparent after 7 days, and thereafter remain stable till the 14th day.
Full Text Available can be achieved. This work provides a complete centrifugal microfluidic platform and the building blocks on which to develop a variety of microfluidic applications and potential products rapidly and at a low cost. ... stream_source_info Hugo_2015_ABSTRACT.pdf.txt stream_content_type text/plain stream_size 1281 Content-Encoding UTF-8 stream_name Hugo_2015_ABSTRACT.pdf.txt Content-Type text/plain; charset=UTF-8 Rapid Product Development...
Kumari, Simpal; Naraian, Ram
Aim of the present study was to evaluate the efficiency of fungal co-culture for the decolorization of synthetic brilliant green carpet industry dye. For this purpose two lignocellulolytic fungi Pleurotus florida (PF) and Rhizoctonia solani (RS) were employed. The study includes determination of enzyme profiles (laccase and peroxidase), dye decolorization efficiency of co-culture and crude enzyme extracts. Both fungi produced laccase and Mn peroxidase and successfully decolorized solutions of different concentrations (2.0, 4.0, 6.0, & 8.0(w/v) of dye. The co-culture resulted highest 98.54% dye decolorization at 2% (w/v) of dye as compared to monocultures (82.12% with PF and 68.89% with RS) during 12 days of submerged fermentation. The lower levels of dyes were rapidly decolorized, while higher levels in slow order as 87.67% decolorization of 8% dye. The promising achievement of the study was remarkable decolorizing efficiency of co-culture over monocultures. The direct treatment of the mono and co-culture enzyme extracts to dye also influenced remarkable. The highest enzymatic decolorization was through combined (PF and RS) extracts, while lesser by monoculture extracts. Based on the observations and potentiality of co-culture technology; further it can be exploited for the bioremediation of areas contaminated with hazardous environmental pollutants including textile and other industry effluents. Copyright © 2016 Elsevier Ltd. All rights reserved.
Background The efficiency of recovery and the detection limit of Legionella after co-culture with Acanthamoeba polyphaga are not known and so far no investigations have been carried out to determine the efficiency of the recovery of Legionella spp. by co-culture and compare it with that of conventional culturing methods. This study aimed to assess the detection limits of co-culture compared to culture for Legionella pneumophila in compost and air samples. Compost and air samples were spiked with known concentrations of L. pneumophila. Direct culturing and co-culture with amoebae were used in parallel to isolate L. pneumophila and recovery standard curves for both methods were produced for each sample. Results The co-culture proved to be more sensitive than the reference method, detecting 102-103 L. pneumophila cells in 1 g of spiked compost or 1 m3 of spiked air, as compared to 105-106 cells in 1 g of spiked compost and 1 m3 of spiked air. Conclusions Co-culture with amoebae is a useful, sensitive and reliable technique to enrich L. pneumophila in environmental samples that contain only low amounts of bacterial cells. PMID:23442526
Paschos, Nikolaos K; Brown, Wendy E; Eswaramoorthy, Rajalakshmanan; Hu, Jerry C; Athanasiou, Kyriacos A
Stem cells are the future in tissue engineering and regeneration. In a co-culture, stem cells not only provide a target cell source with multipotent differentiation capacity, but can also act as assisting cells that promote tissue homeostasis, metabolism, growth and repair. Their incorporation into co-culture systems seems to be important in the creation of complex tissues or organs. In this review, critical aspects of stem cell use in co-culture systems are discussed. Direct and indirect co-culture methodologies used in tissue engineering are described, along with various characteristics of cellular interactions in these systems. Direct cell-cell contact, cell-extracellular matrix interaction and signalling via soluble factors are presented. The advantages of stem cell co-culture strategies and their applications in tissue engineering and regenerative medicine are portrayed through specific examples for several tissues, including orthopaedic soft tissues, bone, heart, vasculature, lung, kidney, liver and nerve. A concise review of the progress and the lessons learned are provided, with a focus on recent developments and their implications. It is hoped that knowledge developed from one tissue can be translated to other tissues. Finally, we address challenges in tissue engineering and regenerative medicine that can potentially be overcome via employing strategies for stem cell co-culture use. Copyright © 2014 John Wiley & Sons, Ltd.
Traore, Mahama Aziz; Behkam, Bahareh
The study of cells in a well-defined and chemically programmable microenvironment is essential for a complete and fundamental understanding of the cell behaviors with respect to specific chemical compounds. Flow-free microfluidic devices that generate quasi-steady chemical gradients (spatially varying but temporally constant) have been demonstrated as effective chemotaxis assay platforms due to dissociating the effect of chemical cues from mechanical shear forces caused by fluid flow. In this work, we demonstrate the fabrication and characterization of a flow-free microfluidic platform made of polyethylene glycol diacrylate (PEG-DA) hydrogel. We have demonstrated that the mass transport properties of these devices can be customized by fabricating them from PEG-DA gels of four distinct molecular weights. In contrast to microfluidic devices developed using soft lithography; this class of devices can be realized using a more cost-effective approach of direct photopolymerization with fewer microfabrication steps. This microfluidic platform was tested by conducting a quantitative study of the chemotactic behavior of Escherichia coli (E. coli) RP437, a model microorganism, in presence of the chemo-effector, casamino-acids. Using the microfabrication and characterization methodology presented in this work, microfluidic platforms with well-defined and customizable diffusive properties can be developed to accommodate the study of a wide range of cell types. (paper)
Gardeniers, Johannes G.E.
Microfluidic systems, and more specifically, microfluidic chips, have a number of features that make them particularly useful for the study of chemical reactions on-line. The present paper will discuss two examples, the study of fluidic behaviour at high pressures and the excitation and detection of
Fan, Ping; He, Lan; Pu, Dan; Lv, Xiaohong; Zhou, Wenxu; Sun, Yining; Hu, Nan
Research highlights: → The proliferation of dramatic increased by co-cultured with Sertoli cells. → VEGF receptor-2 expression of ECs was up-regulated by co-cultured with Sertoli cells. → The MHC expression of ECs induced by INF-γ and IL-6, IL-8 and sICAM induced by TNF-α decreased respectively after co-cultured with Sertoli cells. → ECs co-cultured with Sertoli cells also didn't increase the stimulation index of spleen lymphocytes. -- Abstract: The major problem of the application of endothelial cells (ECs) in transplantation is the lack of proliferation and their immunogenicity. In this study, we co-cultured ECs with Sertoli cells to monitor whether Sertoli cells can influence the proliferation and immunogenicity of co-cultured ECs. Sertoli cells were isolated from adult testicular tissue. ECs were divided into the control group and the experimental group, which included three sub-groups co-cultured with 1 x 10 3 , 1 x 10 4 or 1 x 10 5 cell/ml of Sertoli cells. The growth and proliferation of ECs were observed microscopically, and the expression of vascular endothelial growth factor (VEGF) receptor-2 (KDR) was examined by Western blotting. In another experiment, ECs were divided into the control group, the single culture group and the co-culture group with the optimal concentration of Sertoli cells. After INF-γ and TNF-α were added to the culture medium, MHC II antigen expression was detected by immunofluorescence staining and western blotting; interleukin (IL)-6, IL-8 and soluble intercellular adhesion molecule (sICAM) were measured in the culture medium by ELISA. We demonstrated that 1 x 10 4 cell/ml Sertoli cells promoted the proliferation of co-cultured ECs more dramatically than that in other groups (P 4 cell/ml of the Sertoli cells was most effective in the up-regulation of KDR expression in the co-cultured ECs (P < 0.05). Sertoli cells can effectively suppress INF-γ-induced MHC II antigen expression in co-cultured ECs compared with single
Ren, Kangning; Zhou, Jianhua; Wu, Hongkai
arbitrary 3D structures, while some perfluoropolymers are extremely inert and antifouling. Chemists can use hydrogels as highly permeable structural material, which allows diffusion of molecules without bulk fluid flows. They are used to support 3D cell culture, to form diffusion gradient, and to serve as actuators. Researchers have recently introduced paper-based devices, which are extremely low-cost to prepare and easy to use, thereby promising in commercial point-of-care assays. In general, the evolution of chip materials reflects the two major trends of microfluidic technology: powerful microscale research platforms and low-cost portable analyses. For laboratory research, chemists choosing materials generally need to compromise the ease in prototyping and the performance of the device. However, in commercialization, the major concerns are the cost of production and the ease and reliability in use. There may be new growth in the combination of surface engineering, functional materials, and microfluidics, which is possibly accomplished by the utilization of composite materials or hybrids for advanced device functions. Also, significant expanding of commercial applications can be predicted.
Schulze Greiving-Stimberg, Verena Carolin; Bomer, Johan G.; van Uitert, I.; van den Berg, Albert; le Gac, Severine
A microfluidic platform is reported for various experimentation schemes on cell membrane models and membrane proteins using a combination of electrical and optical measurements, including confocal microscopy. Bilayer lipid membranes (BLMs) are prepared in the device upon spontaneous and
Dai, N.-T.; Yeh, M.-K.; Liu, Demeral David; Adams, E.F.; Chiang, C.-H.; Yen, C.-Y.; Shih, C.-M.; Sytwu, H.-K.; Chen, Tim-Mo; Wang, H.-J.; Williamson, M.R.; Coombes, A.G.A.
Tissue engineering of skin based on collagen: PCL biocomposites using a designed co-culture system is reported. The collagen: PCL biocomposites having collagen: PCL (w/w) ratios of 1:4, 1:8, and 1:20 have been proven to be biocompatible materials to support both adult normal human epidermal Keratinocyte (NHEK) and mouse 3T3 fibroblast growth in cell culture, respectively, by Dai, Coombes, et al. in 2004. Films of collagen: PCL biocomposites were prepared using non-crosslinking method by impregnation of lyophilized collagen mats with PCL/dichloromethane solutions followed by solvent evaporation. To mimic the dermal/epidermal structure of skin, the 1:20 collagen: PCL biocomposites were selected for a feasibility study of a designed co-culture technique that would subsequently be used for preparing fibroblast/biocomposite/keratinocyte skin models. A 55.3% increase in cell number was measured in the designed co-culture system when fibroblasts were seeded on both sides of a biocomposite film compared with cell culture on one surface of the biocomposite in the feasibility study. The co-culture of human keratinocytes and 3T3 fibroblasts on each side of the membrane was therefore studied using the same co-culture system by growing keratinocytes on the top surface of membrane for 3 days and 3T3 fibroblasts underneath the membrane for 6 days. Scanning electron microscopy (SEM) and immunohistochemistry assay revealed good cell attachment and proliferation of both human keratinocytes and 3T3 fibroblasts with these two types of cells isolated well on each side of the membrane. Using a modified co-culture technique, a co-cultured skin model presenting a confluent epidermal sheet on one side of the biocomposite film and fibroblasts populated on the other side of the film was developed successfully in co-culture system for 28 days under investigations by SEM and immunohistochemistry assay. Thus, the design of a co-culture system based on 1:20 (w/w) collagen: PCL biocomposite
Wei, Wei; Xu, Chao; Ye, Zhi-Yong; Huang, Xiao-Jun; Yuan, Jia-En; Ma, Tian-Bao; Lin, Han-Biao; Chen, Xiu-Qiong
The aim of the present study was to obtain the qualified hematopoietic stem/progenitor cells (HSC/HPC) and human umbilical cord-mesenchymal stem cells (MSC) in vitro in the co-culture system. Cord blood mononuclear cells were separated from umbilical cord blood by Ficoll lymphocyte separation medium, and then CD34 + HSC was collected by MACS immunomagnetic beads. The selected CD34 + HSC/HPC and MSC were transferred into culture flask. IMDM culture medium with 15% AB-type cord plasma supplemented with interleukin-3 (IL-3), IL-6, thrombopoietin (TPO), stem cell factor (SCF) and FMS-like tyrosine kinase 3 ligand (Flt-3L) factors were used as the co-culture system for the amplification of HSC/HPC and MSC. The cellular growth status and proliferation on day 6 and 10 after co-culture were observed by using inverted microscope. The percentage of positive expression of CD34 in HSC/HPC, as well as the percentages of positive expressions of CD105, CD90, CD73, CD45, CD34 and HLA-DR in the 4 th generation MSC, was tested by flow cytometry. Semisolid colony culture was used to test the HSC/HPC colony forming ability. The osteogenic, chondrogenesis and adipogenic ability of the 4 th generation MSC were assessed. The karyotype analysis of MSC was conducted by colchicines. The results demonstrated that the HSC/HPC of co-culture group showed higher ability of amplification, CFU-GM and higher CD34 + percentage compared with the control group. The co-cultured MSC maintained the ability to differentiate into bone cells, fat cells and chondrocytes. And the karyotype stability of MSC remained normal. These results reveal that the appropriate co-culture system for MSC and HSC is developed, and via this co-culture system we could gain both two kinds of these cells. The MSCs under the co-culture system maintain the biological characteristics. The CFU-GM ability, cell counting and the flow cytometry results of HSC/HPC under the co-culture system are conform to the criterion, showing that
De Vitis, Stefania; Matarise, Giuseppina; Pardeo, Francesca; Catalano, Rossella; Malara, Natalia Maria; Trunzo, Valentina; Tallerico, Rossana; Gentile, Francesco T.; Candeloro, Patrizio; Coluccio, Maria Laura; Massaro, Alessandro S.; Viglietto, Giuseppe; Carbone, Ennio; Kutter, Jö rg Peter; Perozziello, Gerardo; Di Fabrizio, Enzo M.
The aim of this work is the development of a microfluidic immunosensor for the immobilization of cancer cells and their separation from healthy cells by using "in situ" microfluidic biofunctionalization protocols. These protocols allow to link antibodies on microfluidic device surfaces and can be used to study the interaction between cell membrane and biomolecules. Moreover they allow to perform analysis with high processing speed, small quantity of reagents and samples, short reaction times and low production costs. In this work the developed protocols were used in microfluidic devices for the isolation of cancer cells in heterogeneous blood samples by exploiting the binding of specific antibody to an adhesion protein (EpCAM), overexpressed on the tumor cell membranes. The presented biofunctionalization protocols can be performed right before running the experiment: this allows to have a flexible platform where biomolecules of interest can be linked on the device surface according to the user's needs. © 2014 Elsevier B.V. All rights reserved.
Full Text Available A hydroponic co-culture system was adopted to determine the allelopathic potential of garlic on the growth of pepper plants. Different numbers of garlic plants (0, 2, 4, 8 and 12 were hydroponically co-cultured with two pepper plants to investigate allelopathic effects on the growth attributes and antioxidative defense system of the test pepper plants. The responses of the pepper plants depended on the number of garlic plants included in the co-culture system, indicating an association of pepper growth with the garlic root exudate concentration. When grown at a pepper/garlic ratio of 1:1 or 1:2, the pepper plant height, chlorophyll content, and peroxidase (POD, catalase (CAT and phenylalanine ammonia-lyase (PAL activities were significantly increased after 30 days of co-culture; in contrast, reduction in methane dicarboxylic aldehyde (MDA content was observed. However, when the pepper/garlic ratio was 1:4 or higher, these morphological indices and protective enzyme activities were significantly inhibited, whereas MDA levels in the pepper leaves were significantly increased due to severe membrane lipid peroxidation. The results indicate that although low concentrations of garlic root exudates appear to induce protective enzyme systems and promote pepper growth, high concentrations have deleterious effects. These findings suggest that further investigations should optimize the co-culture pepper/garlic ratio to reduce continuous cropping obstacles in pepper production.
Goers, Lisa; Freemont, Paul; Polizzi, Karen M
Co-culture techniques find myriad applications in biology for studying natural or synthetic interactions between cell populations. Such techniques are of great importance in synthetic biology, as multi-species cell consortia and other natural or synthetic ecology systems are widely seen to hold enormous potential for foundational research as well as novel industrial, medical and environmental applications with many proof-of-principle studies in recent years. What is needed for co-cultures to fulfil their potential? Cell-cell interactions in co-cultures are strongly influenced by the extracellular environment, which is determined by the experimental set-up, which therefore needs to be given careful consideration. An overview of existing experimental and theoretical co-culture set-ups in synthetic biology and adjacent fields is given here, and challenges and opportunities involved in such experiments are discussed. Greater focus on foundational technology developments for co-cultures is needed for many synthetic biology systems to realize their potential in both applications and answering biological questions. © 2014 The Author(s) Published by the Royal Society. All rights reserved.
Zhang, Haoran; Wang, Xiaonan
With the development of metabolic engineering, employment of a selected microbial host for accommodation of a designed biosynthetic pathway to produce a target compound has achieved tremendous success in the past several decades. Yet, increasing requirements for sophisticated microbial biosynthesis call for establishment and application of more advanced metabolic engineering methodologies. Recently, important progress has been made towards employing more than one engineered microbial strains to constitute synthetic co-cultures and modularizing the biosynthetic labor between the co-culture members in order to improve bioproduction performance. This emerging approach, referred to as modular co-culture engineering in this review, presents a valuable opportunity for expanding the scope of the broad field of metabolic engineering. We highlight representative research accomplishments using this approach, especially those utilizing metabolic engineering tools for microbial co-culture manipulation. Key benefits and major challenges associated with modular co-culture engineering are also presented and discussed. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.
Fu, Weili; Xiang, Zhou
To review the research progress of the co-culture system for constructing vascularized tissue engineered bone. The recent literature concerning the co-culture system for constructing vascularized tissue engineered bone was reviewed, including the selection of osteogenic and endothelial lineages, the design and surface modification of scaffolds, the models and dimensions of the co-culture system, the mechanism, the culture conditions, and their application progress. The construction of vascularized tissue engineered bone is the prerequisite for their survival and further clinical application in vivo. Mesenchymal stem cells (owning the excellent osteogenic potential) and endothelial progenitor cells (capable of directional differentiation into endothelial cell) are considered as attractive cell types for the co-culture system to construct vascularized tissue engineered bone. The culture conditions need to be further optimized. Furthermore, how to achieve the clinical goals of minimal invasion and autologous transplantation also need to be further studied. The strategy of the co-culture system for constructing vascularized tissue engineered bone would have a very broad prospects for clinical application in future.
Pandurangan, Muthuraman; Hwang, Inho
Animal cell culture is a highly complex process, in which cells are grown under specific conditions. The growth and development of these cells is a highly unnatural process in vitro condition. Cells are removed from animal tissues and artificially cultured in various culture vessels. Vitamins, minerals, and serum growth factors are supplied to maintain cell viability. Obtaining result homogeneity of in vitro and in vivo experiments is rare, because their structure and function are different. Living tissues have highly ordered complex architecture and are three-dimensional (3D) in structure. The interaction between adjacent cell types is quite distinct from the in vitro cell culture, which is usually two-dimensional (2D). Co-culture systems are studied to analyze the interactions between the two different cell types. The muscle and fat co-culture system is useful in addressing several questions related to muscle modeling, muscle degeneration, apoptosis, and muscle regeneration. Co-culture of C2C12 and 3T3-L1 cells could be a useful diagnostic tool to understand the muscle and fat formation in animals. Even though, co-culture systems have certain limitations, they provide a more realistic 3D view and information than the individual cell culture system. It is suggested that co-culture systems are useful in evaluating the intercellular communication and composition of two different cell types.
Chen, Yu-Chih; Cheng, Yu-Heng; Kim, Hong Sun; Ingram, Patrick N; Nor, Jacques E; Yoon, Euisik
Cancer-stromal cell interactions are a critical process in tumorigenesis. Conventional dish-based assays, which simply mix two cell types, have limitations in three aspects: 1) limited control of the cell microenvironment; 2) inability to study cell behavior in a single-cell manner; and 3) have difficulties in characterizing single cell behavior within a highly heterogeneous cell population (e.g. tumor). An innovative use of microfluidic technology is for improving the spatial resolution for single cell assays. However, it is challenging to isolate the paired interacting cells while maintaining nutrient renewal. In this work, two-phase flow was used as a simple isolation method, separating the microenvironment of each individual chamber. As nutrients in an isolated chamber are consumed by cells, media exchange is required. To connect the cell culture chamber to the media exchange layer, we demonstrated a 3D microsystem integration technique using vertical connections fabricated by deep reactive-ion etching (DRIE). Compared to previous approaches, the presented process allows area reduction of vertical connections by an order of magnitude, enabling compact 3D integration. A semi-permeable membrane was sandwiched between the cell culture layer and the media exchange layer. The selectivity of the semi-permeable membrane results in the retention of the signaling proteins within the chamber while allowing free diffusion of nutrients (e.g., glucose and amino acids). Thus, paracrine signals are accumulated inside the chamber without cross-talk between cells in other chambers. Utilizing these innovations, we co-cultured UM-SCC-1 (head and neck squamous cell carcinoma) cells and endothelial cells to simulate tumor proliferation enhancement in the vascular endothelial niche.
Cheong, Raymond; Paliwal, Saurabh; Levchenko, Andre
Importance of the field Miniaturization is key to advancing the state-of-the-art in high content screening (HCS), in order to enable dramatic cost savings through reduced usage of expensive biochemical reagents and to enable large-scale screening on primary cells. Microfluidic technology offers the potential to enable HCS to be performed with an unprecedented degree of miniaturization. Areas covered in this review This perspective highlights a real-world example from the authors’ work of HCS assays implemented in a highly miniaturized microfluidic format. Advantages of this technology are discussed, including cost savings, high throughput screening on primary cells, improved accuracy, the ability to study complex time-varying stimuli, and ease of automation, integration, and scaling. What the reader will gain The reader will understand the capabilities of a new microfluidics-based platform for HCS, and the advantages it provides over conventional plate-based HCS. Take home message Microfluidics technology will drive significant advancements and broader usage and applicability of HCS in drug discovery. PMID:21852997
Jones, J Andrew; Wang, Xin
The microbial production of chemicals has traditionally relied on a single engineered microbe to enable the complete bioconversion of substrate to final product. Recently, a growing fraction of research has transitioned towards employing a modular co-culture engineering strategy using multiple microbes growing together to facilitate a divide-and-conquer approach for chemical biosynthesis. Here, we review key success stories that leverage the unique advantages of co-culture engineering, while also addressing the critical concerns that will limit the wide-spread implementation of this technology. Future studies that address the need to monitor and control the population dynamics of each strain module, while maintaining robust flux routes towards a wide range of desired products will lead the efforts to realize the true potential of co-culture engineering. Copyright © 2017 Elsevier Ltd. All rights reserved.
Banerjee, Rintu; Mukherjee, Gargi; Patra, Krushna Chandra
Modified solid-state fermentation (MSSF) of tannin-rich substrate yielding tannase and gallic acid was carried out using a co-culture of the filamentous fungi, Rhizopus oryzae (RO IIT RB-13, NRRL 21498) and Aspergillus foetidus (GMRB013 MTCC 3557). Powdered fruits of Terminalia chebula and powdered pod cover of Caesalpinia digyna was used in the process and the different process parameters for maximum production of tannase and gallic acid by co-culture method were optimized through media engineering. MSSF was carried out at the optimum conditions of 30 degrees C and 80% relative humidity. The optimal pH and incubation period was 5.0 and 48 h respectively. Through the co-culture technique the maximum yield of tannase and gallic acid was found to be 41.3 U/ml and 94.8% respectively.
Varshney, Rohan R; Zhou, Ruijie; Hao, Jinghua; Yeo, Suan Siong; Chooi, Wai Hon; Fan, Jiabing; Wang, Dong-An
A co-culture strategy has been developed in this study wherein rabbit synovial mesenchymal stem cells (SMSCs) are co-cultured with growth factor (GF) transfected articular chondrocytes. Toward this end, both SMSCs and early passage rabbit articular chondrocytes that had been adenovirally transduced with transforming growth factor-beta 3 (TGF-beta3) gene were separately encapsulated in alginate beads and co-cultured in the same pool of chondrogenic medium. The chondrocytes act as transfected companion cells (TCCs) providing GF supply to induce chondrogenic differentiation of SMSCs that play the role of therapeutic progenitor cells (TPCs). Against the same TCC based TGF-beta3 release profile, the co-culture was started at different time points (Day 0, Day 10 and Day 20) but made to last for identical periods of exposure (30 days) so that the exposure conditions could be optimized in terms of initiation and duration. Transfection of TCCs prevents the stem cell based TPCs from undergoing the invasive procedure. It also prevents unpredictable complications in the TPCs caused by long-term constitutive over-expression of a GF. The adenovirally transfected TCCs exhibit a transient GF expression which results in a timely termination of GF supply to the TPCs. The TCC-sourced transgenic TGF-beta3 successfully induced chondrogenesis in the TPCs. Real-time PCR results show enhanced expression of cartilage markers and immuno/histochemical staining for Glycosaminoglycans (GAG) and Collagen II also shows abundant extracellular matrix (ECM) production and chondrogenic morphogenesis in the co-cultured TPCs. These results confirm the efficacy of directing stem cell differentiation towards chondrogenesis and cartilage tissue formation by co-culturing them with GF transfected chondrocytes.
Ou, Dong-Bo; He, Yong; Chen, Rui; Teng, Ji-Wei; Wang, Hong-Tao; Zeng, Di; Liu, Xiong-Tao; Ding, Lu; Huang, Jin-Yan; Zheng, Qiang-Sun
The cardiomyocyte (CM) differentiation of embryonic stem cells (ESCs) is routinely cultured as two-dimensional (2D) monolayer, which doesn't mimic in vivo physiological environment and may lead to low differentiated level of ESCs. Here, we develop a novel strategy that enhances CM differentiation of ESCs in collagen matrix three-dimensional (3D) culture combined with indirect cardiac fibroblasts co-culture. ESCs were cultured in hanging drops to form embryoid bodies (EBs) and then applied on collagen matrix. The EBs were indirectly co-cultured with cardiac fibroblasts by the hanging cell culture inserts (PET 1 µm). The molecular expressions and ultrastructural characteristics of ESC-derived CMs (ESCMs) were analyzed by real time RT-PCR, immunocytochemistry, and Transmission Electron Microscopy (TEM). We found that the percentage of beating EBs with cardiac fibroblasts co-culture was significantly higher than that without co-culture after differentiation period of 8 days. Type I collagen used as 3D substrates enhanced the late-stage CM differentiation of ESCs and had effect on ultrastructural mature of ESCMs in late-stage development. The combined effects of 3D and co-culture that mimic in vivo physiological environment further improved the efficiency of CM differentiation from ESCs, resulting in fiber-like structures of cardiac cells with organized sarcomeric structure in ESCMs. This novel 3D co-culture system emphasizes the fact that the ESC differentiation is actively responding to cues from their environment and those cues can drive phenotypic control, which provides a useful in vitro model to investigate CM differentiation of stem cells. Copyright © 2011 Wiley Periodicals, Inc.
Yun, Hoyoung; Kim, Kisoo; Lee, Won Gu
Recent advances in the lab-on-a-chip field in association with nano/microfluidics have been made for new applications and functionalities to the fields of molecular biology, genetic analysis and proteomics, enabling the expansion of the cell biology field. Specifically, microfluidics has provided promising tools for enhancing cell biological research, since it has the ability to precisely control the cellular environment, to easily mimic heterogeneous cellular environment by multiplexing, and to analyze sub-cellular information by high-contents screening assays at the single-cell level. Various cell manipulation techniques in microfluidics have been developed in accordance with specific objectives and applications. In this review, we examine the latest achievements of cell manipulation techniques in microfluidics by categorizing externally applied forces for manipulation: (i) optical, (ii) magnetic, (iii) electrical, (iv) mechanical and (v) other manipulations. We furthermore focus on history where the manipulation techniques originate and also discuss future perspectives with key examples where available. (topical review)
Lee, Chung-cheng [Irvine, CA; Sui, Guodong [Los Angeles, CA; Elizarov, Arkadij [Valley Village, CA; Kolb, Hartmuth C [Playa del Rey, CA; Huang, Jiang [San Jose, CA; Heath, James R [South Pasadena, CA; Phelps, Michael E [Los Angeles, CA; Quake, Stephen R [Stanford, CA; Tseng, Hsian-rong [Los Angeles, CA; Wyatt, Paul [Tipperary, IE; Daridon, Antoine [Mont-Sur-Rolle, CH
New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.
Wang, Zhenyu; Cao, Guangli; Zheng, Ju; Fu, Defeng; Song, Jinzhu; Zhang, Junzheng; Zhao, Lei; Yang, Qian
Consolidated bioprocessing (CBP) of butanol production from cellulosic biomass is a promising strategy for cost saving compared to other processes featuring dedicated cellulase production. CBP requires microbial strains capable of hydrolyzing biomass with enzymes produced on its own with high rate and high conversion and simultaneously produce a desired product at high yield. However, current reported butanol-producing candidates are unable to utilize cellulose as a sole carbon source and energy source. Consequently, developing a co-culture system using different microorganisms by taking advantage of their specific metabolic capacities to produce butanol directly from cellulose in consolidated bioprocess is of great interest. This study was mainly undertaken to find complementary organisms to the butanol producer that allow simultaneous saccharification and fermentation of cellulose to butanol in their co-culture under mesophilic condition. Accordingly, a highly efficient and stable consortium N3 on cellulose degradation was first developed by multiple subcultures. Subsequently, the functional microorganisms with 16S rRNA sequences identical to the denaturing gradient gel electrophoresis (DGGE) profile were isolated from consortium N3. The isolate Clostridium celevecrescens N3-2 exhibited higher cellulose-degrading capability was thus chosen as the partner strain for butanol production with Clostridium acetobutylicum ATCC824. Meanwhile, the established stable consortium N3 was also investigated to produce butanol by co-culturing with C. acetobutylicum ATCC824. Butanol was produced from cellulose when C. acetobutylicum ATCC824 was co-cultured with either consortium N3 or C. celevecrescens N3-2. Co-culturing C. acetobutylicum ATCC824 with the stable consortium N3 resulted in a relatively higher butanol concentration, 3.73 g/L, and higher production yield, 0.145 g/g of glucose equivalent. The newly isolated microbial consortium N3 and strain C. celevecrescens N3
Poulsen, Carl Esben
In this PhD project, I pursued to develop an all-polymer injection moulded microfluidic platform with integrated droplet based single cell interrogation. To allow for a proper ”one device - one experiment” methodology and to ensure a high relevancy to non-academic settings, the systems presented ...
Mela, P.; Onclin, S.; Goedbloed, M.H.; Levi, S.; Garcia Parajo, M.F.; van Hulst, N.F.; Ravoo, B.J.; Reinhoudt, David; van den Berg, Albert
This paper describes the integration of opto-chemosensors in microfluidics networks. Our technique exploits the internal surface of the network as a platform to build a sensing system by coating the surface with a self-assembled monolayer and subsequently binding a fluorescent sensing molecule to
Saccharomyces cerevisiae and Aspergillus niger were used in a co-culture for the simultaneous saccharification and fermentation (SSF) of 1% and 10% (w/v) dry pre-treated corn cobs to ethanol. Positive controls of glucose of same concentrations in a synthetic medium were also fermented. At 1% substrate concentration, ...
Abreu, Angela A; Tavares, Fábio; Alves, Maria Madalena; Pereira, Maria Alcina
Proof of principle of biohythane and potential energy production from garden waste (GW) is demonstrated in this study in a two-step process coupling dark fermentation and anaerobic digestion. The synergistic effect of using co-cultures of extreme thermophiles to intensify biohydrogen dark fermentation is demonstrated using xylose, cellobiose and GW. Co-culture of Caldicellulosiruptor saccharolyticus and Thermotoga maritima showed higher hydrogen production yields from xylose (2.7±0.1molmol(-1) total sugar) and cellobiose (4.8±0.3molmol(-1) total sugar) compared to individual cultures. Co-culture of extreme thermophiles C. saccharolyticus and Caldicellulosiruptor bescii increased synergistically the hydrogen production yield from GW (98.3±6.9Lkg(-1) (VS)) compared to individual cultures and co-culture of T. maritima and C. saccharolyticus. The biochemical methane potential of the fermentation end-products was 322±10Lkg(-1) (CODt). Biohythane, a biogas enriched with 15% hydrogen could be obtained from GW, yielding a potential energy generation of 22.2MJkg(-1) (VS). Copyright © 2016 Elsevier Ltd. All rights reserved.
Nielsen, Line Hagner; De Rossi, C.; Lehr, C-M.
; this was not observed with ovalbumin and blank solution. An example of the results is shown in Figure 2 for IL-17A. An established co-culture of Caco-2, THP-1 and MUTZ-3 cells showed promise as an in vitro model for testing of oral vaccine formulations. Mobility of co-culture immune cells as well as cytokine production......A triple co-culture cell model of Caco-2 cells, dendritic cells and macrophages (Figure 1) has previously been developed for studying intestinal permeability in a state of inflammation ,. The aim of this study was to investigate the applicability of this cell model for testing...... the model antigen ovalbumin was spray dried to obtain a particulate vaccine model system for testing in the cell model. The precursors were shown to form cubosomes when dispersed in aqueous medium, and was therefore used as the vaccine formulation for testing on the co-cultures. After 11 days, the TEER...
Kaji, Hirokazu; Camci-Unal, Gulden; Langer, Robert; Khademhosseini, Ali
Inside the body, cells lie in direct contact or in close proximity to other cell types in a tightly controlled architecture that often regulates the resulting tissue function. Therefore, tissue engineering constructs that aim to reproduce the architecture and the geometry of tissues will benefit from methods of controlling cell-cell interactions with microscale resolution. We discuss the use of microfabrication technologies for generating patterned co-cultures. In addition, we categorize patterned co-culture systems by cell type and discuss the implications of regulating cell-cell interactions in the resulting biological function of the tissues. Patterned co-cultures are a useful tool for fabricating tissue engineered constructs and for studying cell-cell interactions in vitro, because they can be used to control the degree of homotypic and heterotypic cell-cell contact. In addition, this approach can be manipulated to elucidate important factors involved in cell-matrix interactions. Patterned co-culture strategies hold significant potential to develop biomimetic structures for tissue engineering. It is expected that they would create opportunities to develop artificial tissues in the future. This article is part of a Special Issue entitled Nanotechnologies - Emerging Applications in Biomedicine. 2010 Elsevier B.V. All rights reserved.
Zhang, Yu; Guo, Weimin; Wang, Mingjie; Hao, Chunxiang; Lu, Liang; Gao, Shuang; Zhang, Xueliang; Li, Xu; Chen, Mingxue; Li, Penghao; Jiang, Peng; Lu, Shibi; Liu, Shuyun; Guo, Quanyi
Cartilage engineering facilitates repair and regeneration of damaged cartilage using engineered tissue that restores the functional properties of the impaired joint. The seed cells used most frequently in tissue engineering, are chondrocytes and mesenchymal stem cells. Seed cells activity plays a key role in the regeneration of functional cartilage tissue. However, seed cells undergo undesirable changes after in vitro processing procedures, such as degeneration of cartilage cells and induced hypertrophy of mesenchymal stem cells, which hinder cartilage tissue engineering. Compared to monoculture, which does not mimic the in vivo cellular environment, co-culture technology provides a more realistic microenvironment in terms of various physical, chemical, and biological factors. Co-culture technology is used in cartilage tissue engineering to overcome obstacles related to the degeneration of seed cells, and shows promise for cartilage regeneration and repair. In this review, we focus first on existing co-culture systems for cartilage tissue engineering and related fields, and discuss the conditions and mechanisms thereof. This is followed by methods for optimizing seed cell co-culture conditions to generate functional neo-cartilage tissue, which will lead to a new era in cartilage tissue engineering. © 2017 Wiley Periodicals, Inc.
Full Text Available Non-parenchymal cells might play an important role in the modulation of xenobiotic metabolism in liver and its pharmacological and toxicological consequences. Therefore, the role of cell-to-cell interactions in herbal induced liver toxicity was investigated in monocultures of cells from the human hepatocyte cell line (HepG2 and in co-cultures of cells from the HepG2 cell line and cells from the human monocyte cell line (THP1. Cells were treated with various concentrations (1–500 µg ml−1 of extracts of Pistacia palaestina, Juglans regia and Quercus ithaburensis for 24 h. Extracts from Cleome droserifolia, a known toxic plant, were taken as positive control. In the co-culture system, toxic effects were observed after exposure to extracts of Pistacia palestina and C. droserifolia. These two extracts significantly reduced by cell viability as measured the MTT test and the LDH assay. Whereas in hepatocyte cultures, only extracts of C. droserifolia were found to affect the cell viability. The production levels of albumin from hepatocytes were not affected by treatment with plant extracts in both culture systems. It seems that the observed reduction in cell viability after exposure to extracts of P. palestina in co-cultures but not in monocultures is a result of monocyte-derived factors. The use of liver cell co-cultures is therefore a useful approach to investigate the influence of intercellular communication on xenobiotic metabolism in liver.
Xu, Lei; Tschirner, Ulrike
Clostridium thermocellum/Clostridium thermolacticum co-culture fermentation has been shown to be a promising way of producing ethanol from several carbohydrates. In this research, immobilization techniques using sodium alginate and alkali pretreatment were successfully applied on this co-culture to improve the bio-ethanol fermentation performance during consolidated bio-processing (CBP). The ethanol yield obtained increased by over 60 % (as a percentage of the theoretical maximum) as compared to free cell fermentation. For cellobiose under optimized conditions, the ethanol yields were approaching about 85 % of the theoretical efficiency. To examine the feasibility of this immobilization co-culture on lignocellulosic biomass conversion, untreated and pretreated aspen biomasses were also used for fermentation experiments. The immobilized co-culture shows clear benefits in bio-ethanol production in the CBP process using pretreated aspen. With a 3-h, 9 % NaOH pretreatment, the aspen powder fermentation yields approached 78 % of the maximum theoretical efficiency, which is almost twice the yield of the untreated aspen fermentation.
Full Text Available Background: The aim of this study was to evaluate fibroblast co-culture on in vitro maturation andfertilization of prepubertal mouse preantral follicles.Materials and Methods: The ovaries of 12-14 day old mice were dissected and 120-150 μmintact preantral follicles with one or two layers of granulosa cells, and round oocytes were culturedindividually in α-minimal essential medium (α-MEM supplemented with 5% fetal bovine serum(FBS, 100 mIU/ml recombinant follicle stimulating hormone, 1% insulin, transferrin, seleniummix, 100 μg/ml penicillin and 50 μg/ml streptomycin as base medium for 12 days. A total number of226 follicules were cultured under two conditions: i base medium as control group (n=113; ii basemedium co-cultured with mouse embryonic fibroblast (MEF (n=113. Follicular diameters, alone,in addition to other factors were analyzed by student’s t-test and chi-square test, respectively.Results: The co-culture group showed significant differences (p<0.05 in growth rate (days 4, 6 and8 of the culture period and survival rate. However, there was no significant difference in antrumformation, ovulation rate and embryonic development of released oocytes. There were significantdifferences (p<0.05 in the estradiol and progesterone secretion at all days between the co-cultureand control groups.Conclusion: Fibroblast co-culture increased survival rate and steroid production of preantralfollicles by promoting granulosa cell proliferation.
Full Text Available In this paper, we describe the effects of the combination of topographical, mechanical, chemical and intracellular electrical stimuli on a co-culture of fibroblasts and skeletal muscle cells. The co-culture was anisotropically grown onto an engineered micro-grooved (10 µm-wide grooves polyacrylamide substrate, showing a precisely tuned Young's modulus (∼ 14 kPa and a small thickness (∼ 12 µm. We enhanced the co-culture properties through intracellular stimulation produced by piezoelectric nanostructures (i.e., boron nitride nanotubes activated by ultrasounds, thus exploiting the ability of boron nitride nanotubes to convert outer mechanical waves (such as ultrasounds in intracellular electrical stimuli, by exploiting the direct piezoelectric effect. We demonstrated that nanotubes were internalized by muscle cells and localized in both early and late endosomes, while they were not internalized by the underneath fibroblast layer. Muscle cell differentiation benefited from the synergic combination of topographical, mechanical, chemical and nanoparticle-based stimuli, showing good myotube development and alignment towards a preferential direction, as well as high expression of genes encoding key proteins for muscle contraction (i.e., actin and myosin. We also clarified the possible role of fibroblasts in this process, highlighting their response to the above mentioned physical stimuli in terms of gene expression and cytokine production. Finally, calcium imaging-based experiments demonstrated a higher functionality of the stimulated co-cultures.
Takanari, Hiroki; Miwa, Keiko; Fu, Xian Ming; Nakai, Junichi; Ito, Akira; Ino, Kousuke; Honda, Hiroyuki; Tonomura, Wataru; Konishi, Satoshi; Opthof, Tobias; van der Heyden, Marcel A G; Kodama, Itsuo; Lee, Jong Kook
Skeletal myoblast (SkMB) transplantation has been conducted as a therapeutic strategy for severe heart failure. However, arrhythmogenicity following transplantation remains unsolved. We developed an in vitro model of myoblast transplantation with “patterned” or “randomly-mixed” co-culture of SkMBs
Takanari, Hiroki; Miwa, Keiko; Fu, Xianming; Nakai, Junichi; Ito, Akira; Ino, Kousuke; Honda, Hiroyuki; Tonomura, Wataru; Konishi, Satoshi; Opthof, Tobias; van der Heyden, Marcel Ag; Kodama, Itsuo; Lee, Jong-Kook
Skeletal myoblast (SkMB) transplantation has been conducted as a therapeutic strategy for severe heart failure. However, arrhythmogenicity following transplantation remains unsolved. We developed an in vitro model of myoblast transplantation with "patterned" or "randomly-mixed" co-culture of SkMBs
Matthew M. Cook
Full Text Available Haematopoietic stem cell (HSC transplantation is an established cell-based therapy for a number of haematological diseases. To enhance this therapy, there is considerable interest in expanding HSCs in artificial niches prior to transplantation. This study compared murine HSC expansion supported through co-culture on monolayers of either undifferentiated mesenchymal stromal cells (MSCs or osteoblasts. Sorted Lineage− Sca-1+ c-kit+ (LSK haematopoietic stem/progenitor cells (HPC demonstrated proliferative capacity on both stromal monolayers with the greatest expansion of LSK shown in cultures supported by osteoblast monolayers. After transplantation, both types of bulk-expanded cultures were capable of engrafting and repopulating lethally irradiated primary and secondary murine recipients. LSKs co-cultured on MSCs showed comparable, but not superior, reconstitution ability to that of freshly isolated LSKs. Surprisingly, however, osteoblast co-cultured LSKs showed significantly poorer haematopoietic reconstitution compared to LSKs co-cultured on MSCs, likely due to a delay in short-term reconstitution. We demonstrated that stromal monolayers can be used to maintain, but not expand, functional HSCs without a need for additional haematopoietic growth factors. We also demonstrated that despite apparently superior in vitro performance, co-injection of bulk cultures of osteoblasts and LSKs in vivo was detrimental to recipient survival and should be avoided in translation to clinical practice.
We studied the expression of inducible heat shock protein (HSP27, HSP72) and multidrug-resistance protein (MRP) in co-cultures of human colon carcinoma cell spheroids obtained from different grades of tumour with normal human colon epithelium, myofibroblast and endothelial cell monolayers. We also measured the ...
Liu, Jing; Arneborg, Nils; Toldam-Andersen, Torben Bo
-phenylethyl acetate. This co-culture fermentation also produced higher amounts of ethyl acetate and acetic acid, reducing the possibility of its use in winemaking. Three Metschnikowia strains, a M. chrysoperlae strain and two M. fructicola strains, gave a comparable production of volatile compounds...
Hussain, Ali; Collins, George; Yip, Derek; Cho, Cheul H
The in vitro generation of a three-dimensional (3-D) myocardial tissue-like construct employing cells, biomaterials, and biomolecules is a promising strategy in cardiac tissue regeneration, drug testing, and tissue engineering applications. Despite significant progress in this field, current cardiac tissue models are not yet able to stably maintain functional characteristics of cardiomyocytes for long-term culture and therapeutic purposes. The objective of this study was to fabricate bioactive 3-D chitosan nanofiber scaffolds using an electrospinning technique and exploring its potential for long-term cardiac function in the 3-D co-culture model. Chitosan is a natural polysaccharide biomaterial that is biocompatible, biodegradable, non-toxic, and cost effective. Electrospun chitosan was utilized to provide structural scaffolding characterized by scale and architectural resemblance to the extracellular matrix (ECM) in vivo. The chitosan fibers were coated with fibronectin via adsorption in order to enhance cellular adhesion to the fibers and migration into the interfibrous milieu. Ventricular cardiomyocytes were harvested from neonatal rats and studied in various culture conditions (i.e., mono- and co-cultures) for their viability and function. Cellular morphology and functionality were examined using immunofluorescent staining for alpha-sarcomeric actin (SM-actin) and gap junction protein, Connexin-43 (Cx43). Scanning electron microscopy (SEM) and light microscopy were used to investigate cellular morphology, spatial organization, and contractions. Calcium indicator was used to monitor calcium ion flux of beating cardiomyocytes. The results demonstrate that the chitosan nanofibers retained their cylindrical morphology in long-term cell cultures and exhibited good cellular attachment and spreading in the presence of adhesion molecule, fibronectin. Cardiomyocyte mono-cultures resulted in loss of cardiomyocyte polarity and islands of non-coherent contractions. However
Kim, Sun-Ah; Lee, Eun Kyung; Kuh, Hyo-Jeong
Epithelial–mesenchymal transition (EMT) acts as a facilitator of metastatic dissemination in the invasive margin of malignant tumors where active tumor–stromal crosstalks take place. Co-cultures of cancer cells with cancer-associated fibroblasts (CAFs) are often used as in vitro models of EMT. We established a tumor–fibroblast proximity co-culture using HT-29 tumor spheroids (TSs) with CCD-18co fibroblasts. When co-cultured with TSs, CCD-18co appeared activated, and proliferative activity as well as cell migration increased. Expression of fibronectin increased whereas laminin and type I collagen decreased in TSs co-cultured with fibroblasts compared to TSs alone, closely resembling the margin of in vivo xenograft tissue. Active TGFβ1 in culture media significantly increased in TS co-cultures but not in 2D co-cultures of cancer cells–fibroblasts, indicating that 3D context-associated factors from TSs may be crucial to crosstalks between cancer cells and fibroblasts. We also observed in TSs co-cultured with fibroblasts increased expression of α-SMA, EGFR and CTGF; reduced expression of membranous β-catenin and E-cadherin, together suggesting an EMT-like changes similar to a marginal region of xenograft tissue in vivo. Overall, our in vitro TS–fibroblast proximity co-culture mimics the EMT-state of the invasive margin of in vivo tumors in early metastasis. - Highlights: • An adjacent co-culture of tumor spheroids and fibroblasts is presented as EMT model. • Activation of fibroblasts and increased cell migration were shown in co-culture. • Expression of EMT-related factors in co-culture was similar to that in tumor tissue. • Crosstalk between spheroids and fibroblasts was demonstrated by secretome analysis
Kim, Sun-Ah, E-mail: email@example.com [Department of Biomedicine & Health Sciences, College of Medicine, The Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Lee, Eun Kyung, E-mail: firstname.lastname@example.org [Department of Biochemistry, College of Medicine, The Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Cancer Evolution Research Center, College of Medicine, The Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Kuh, Hyo-Jeong, E-mail: email@example.com [Department of Biomedicine & Health Sciences, College of Medicine, The Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Cancer Evolution Research Center, College of Medicine, The Catholic University of Korea, Seoul 137-701 (Korea, Republic of)
Epithelial–mesenchymal transition (EMT) acts as a facilitator of metastatic dissemination in the invasive margin of malignant tumors where active tumor–stromal crosstalks take place. Co-cultures of cancer cells with cancer-associated fibroblasts (CAFs) are often used as in vitro models of EMT. We established a tumor–fibroblast proximity co-culture using HT-29 tumor spheroids (TSs) with CCD-18co fibroblasts. When co-cultured with TSs, CCD-18co appeared activated, and proliferative activity as well as cell migration increased. Expression of fibronectin increased whereas laminin and type I collagen decreased in TSs co-cultured with fibroblasts compared to TSs alone, closely resembling the margin of in vivo xenograft tissue. Active TGFβ1 in culture media significantly increased in TS co-cultures but not in 2D co-cultures of cancer cells–fibroblasts, indicating that 3D context-associated factors from TSs may be crucial to crosstalks between cancer cells and fibroblasts. We also observed in TSs co-cultured with fibroblasts increased expression of α-SMA, EGFR and CTGF; reduced expression of membranous β-catenin and E-cadherin, together suggesting an EMT-like changes similar to a marginal region of xenograft tissue in vivo. Overall, our in vitro TS–fibroblast proximity co-culture mimics the EMT-state of the invasive margin of in vivo tumors in early metastasis. - Highlights: • An adjacent co-culture of tumor spheroids and fibroblasts is presented as EMT model. • Activation of fibroblasts and increased cell migration were shown in co-culture. • Expression of EMT-related factors in co-culture was similar to that in tumor tissue. • Crosstalk between spheroids and fibroblasts was demonstrated by secretome analysis.
Hunziker, Patrick R; Wolf, Marc P; Wang, Xueya; Zhang, Bei; Marsch, Stephan; Salieb-Beugelaar, Georgette B
Microfluidic systems represent a key-enabling platform for novel diagnostic tools for use at the point-of-care in clinical contexts as well as for evolving single cell diagnostics. The design of 3D microfluidic systems is an active field of development, but construction of true interconnected 3D microfluidic networks is still a challenge, in particular when the goal is rapid prototyping, accurate design and flexibility. We report a novel approach for the construction of programmable 3D microfluidic systems consisting of modular 3D template casting of interconnected threads to allow user-programmable flow paths and examine its structural characteristics and its modular function. To overcome problems with thread template casting reported in the literature, low-surface-energy polymer threads were used, that allow solvent-free production. Connected circular channels with excellent roundness and low diameter variability were created. Variable channel termination allowed programming a flow path on-the-fly, thus rendering the resulting 3D microfluidic systems highly customizable even after production. Thus, construction of programmable/reprogrammable fully 3D microfluidic systems by template casting of a network of interconnecting threads is feasible, leads to high-quality and highly reproducible, complex 3D geometries. (paper)
James Jam Jolly
Full Text Available Osteoblasts (OBs and osteoclasts (OCs are 2 major groups of bone cells. Their cell-to-cell interactions are important to ensure the continuity of the bone-remodeling process. Therefore, the present study was carried out to optimize an OB/OC co-culture system utilizing the human OB cell line hFOB 1.19 and OCs extracted from peripheral blood mononuclear cells (PBMNCs. It was a 2-step procedure, involving the optimization of the OB culture and the co-culture of the OBs with PBMNCs at an optimum ratio. Firstly, pre-OBs were cultured to 90% confluency and the time required for differentiation was determined. OB differentiation was determined using the van Gieson staining to detect the presence of collagen and Alizarin Red for calcium. Secondly, OBs and OCs were co-cultured at the ratios of 1 OC: 1 OB, 1 OC: 4 OBs, 2 OCs: 1 OB, and 1 OC: 2 OBs. Tartrate-resistant acid phosphatase (TRAP staining was used to detect the differentiation of the OCs. The results showed that collagen was present on day 1, whereas calcium was detected as early as day 3. Based on the result of TRAP staining, 1 OC: 2 OBs was taken as the most appropriate ratio. No macrophage colony-stimulating factor and receptor activator of the nuclear factor-κB ligand were added because they were provided by the OBs. In conclusion, these optimization processes are vital as they ensure the exact time point and ratio of the OB/OC co-culture in order to produce a reliable and reproducible co-culture system.
Mujtaba, Ghulam; Lee, Kisay
The use of algal-bacterial symbiotic association establishes a sustainable and cost-effective strategy in wastewater treatment. Using municipal wastewater, the removal performances of inorganic nutrients (nitrogen and phosphorus) and organic pollutants were investigated by the co-culture system having different inoculum ratios (R) of suspended activated sludge to alginate-immobilized microalgae Chlorella vulgaris. The co-culture reactors with lower R ratios obtained more removal of nitrogen than in pure culture of C. vulgaris. The reactor with R = 0.5 (sludge/microalgae) showed the highest performance representing 66% removal after 24 h and 95% removal after 84 h. Phosphorus was completely eliminated (100%) in the co-culture system with inoculum ratios of 0.5 and 1.0 after 24 h and in the pure C. vulgaris culture after 36 h. The COD level was greatly reduced in the activated sludge reactor, while, it was increasing in pure C. vulgaris culture after 24 h of incubation. However, COD was almost stabilized after 24 h in the reactors with high R ratios such as 2.0, 5.0, and 10 due to the higher concentration of activated sludge. The growth of C. vulgaris was promoted from 0.03 g/L/d to 0.05 g/L/d in the co-culture of low inoculum ratios such as R = 0.5, implying that there exist an optimum inoculum ratio in the co-culture system in order to achieve efficient removal of nutrients. Copyright © 2017 Elsevier Ltd. All rights reserved.
Zhang, Fenxi; Hong, Yan; Liang, Wenmei; Ren, Tongming; Jing, Suhua; Lin, Juntang
Highlights: ► Co-culture of Sertoli cells (SCs) with human umbilical cord mesenchymal stem cells (UCMSCs). ► Presence of SCs dramatically increased proliferation and migration of UCMSCs. ► Presence of SCs stimulated expression of Mdm2, Akt, CDC2, Cyclin D, CXCR4, MAPKs. -- Abstract: Human umbilical cord mesenchymal stem cells (hUCMSCs) have been recently used in transplant therapy. The proliferation and migration of MSCs are the determinants of the efficiency of MSC transplant therapy. Sertoli cells are a kind of “nurse” cells that support the development of sperm cells. Recent studies show that Sertoli cells promote proliferation of endothelial cells and neural stem cells in co-culture. We hypothesized that co-culture of UCMSCs with Sertoli cells may also promote proliferation and migration of UCMSCs. To examine this hypothesis, we isolated UCMSCs from human cords and Sertoli cells from mouse testes, and co-cultured them using a Transwell system. We found that UCMSCs exhibited strong proliferation ability and potential to differentiate to other cell lineages such as osteocytes and adipocytes. The presence of Sertoli cells in co-culture significantly enhanced the proliferation and migration potential of UCMSCs (P < 0.01). Moreover, these phenotypic changes were accompanied with upregulation of multiple genes involved in cell proliferation and migration including phospho-Akt, Mdm2, phospho-CDC2, Cyclin D1, Cyclin D3 as well as CXCR4, phospho-p44 MAPK and phospho-p38 MAPK. These findings indicate that Sertoli cells boost UCMSC proliferation and migration potential.
Antoine, Delphine; Pellequer, Yann; Tempesta, Camille; Lorscheidt, Stefan; Kettel, Bernadette; Tamaddon, Lana; Jannin, Vincent; Demarne, Frédéric; Lamprecht, Alf; Béduneau, Arnaud
Cell culture models are currently used to predict absorption pattern of new compounds and formulations in the human gastro-intestinal tract (GIT). One major drawback is the lack of relevant apical incubation fluids allowing mimicking luminal conditions in the GIT. Here, we suggest a culture model compatible with biorelevant media, namely Fasted State Simulated Intestinal Fluid (FaSSIF) and Fed State Simulated Intestinal Fluid (FeSSIF). Co-culture was set up from Caco-2 and mucus-secreting HT29-MTX cells using an original seeding procedure. Viability and cytotoxicity assays were performed following incubation of FeSSIF and FaSSIF with co-culture. Influence of biorelevant fluids on paracellular permeability or transporter proteins were also evaluated. Results were compared with Caco-2 and HT29-MTX monocultures. While Caco-2 viability was strongly affected with FeSSIF, no toxic effect was detected for the co-cultures in terms of viability and lactate dehydrogenase release. The addition of FeSSIF to the basolateral compartment of the co-culture induced cytotoxic effects which suggested the apical mucus barrier being cell protective. In contrast to FeSSIF, FaSSIF induced a slight increase of the paracellular transport and both tested media inhibited partially the P-gp-mediated efflux in the co-culture. Additionally, the absorptive transport of propranolol hydrochloride, a lipophilic β-blocker, was strongly affected by biorelevant fluids. This study demonstrated the compatibility of the Caco-2/HT29-MTX model with some of the current biorelevant media. Combining biorelevant intestinal fluids with features such as mucus secretion, adjustable paracellular and P-gp mediated transports, is a step forward to more realistic in-vitro models of the human intestine. Copyright © 2015. Published by Elsevier B.V.
Xiu, Yu; Jang, Sungho; Jones, J Andrew; Zill, Nicholas A; Linhardt, Robert J; Yuan, Qipeng; Jung, Gyoo Yeol; Koffas, Mattheos A G
The ability to design and construct combinatorial synthetic metabolic pathways has far exceeded our capacity for efficient screening and selection of the resulting microbial strains. The need for high-throughput rapid screening techniques is of upmost importance for the future of synthetic biology and metabolic engineering. Here we describe the development of an RNA riboswitch-based biosensor module with dual fluorescent reporters, and demonstrate a high-throughput flow cytometry-based screening method for identification of naringenin over producing Escherichia coli strains in co-culture. Our efforts helped identify a number of key operating parameters that affect biosensor performance, including the selection of promoter and linker elements within the sensor-actuator domain, and the effect of host strain, fermentation time, and growth medium on sensor dynamic range. The resulting biosensor demonstrates a high correlation between specific fluorescence of the biosensor strain and naringenin titer produced by the second member of the synthetic co-culture system. This technique represents a novel application for synthetic microbial co-cultures and can be expanded from naringenin to any metabolite if a suitable riboswitch is identified. The co-culture technique presented here can be applied to a variety of target metabolites in combination with the SELEX approach for aptamer design. Due to the compartmentalization of the two genetic constructs responsible for production and detection into separate cells and application as independent modules of a synthetic microbial co-culture we have subsequently reduced the need for re-optimization of the producer module when the biosensor is replaced or removed. Biotechnol. Bioeng. 2017;114: 2235-2244. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Zhang, Fenxi, E-mail: firstname.lastname@example.org [Department of Anatomy, Sanquan College, Xinxiang Medical University, Henan 453003, People' s Republic of China (China); Hong, Yan; Liang, Wenmei [Department of Histology and Embryology, Guiyang Medical University, Guizhou 550004, People' s Republic of China (China); Ren, Tongming [Department of Anatomy, Sanquan College, Xinxiang Medical University, Henan 453003, People' s Republic of China (China); Jing, Suhua [ICU Center, The Third Hospital of Xinxiang Medical University, Henan 453003, People' s Republic of China (China); Lin, Juntang [Stem Cell Center, Xinxiang Medical University, Henan 453003, People' s Republic of China (China)
Highlights: Black-Right-Pointing-Pointer Co-culture of Sertoli cells (SCs) with human umbilical cord mesenchymal stem cells (UCMSCs). Black-Right-Pointing-Pointer Presence of SCs dramatically increased proliferation and migration of UCMSCs. Black-Right-Pointing-Pointer Presence of SCs stimulated expression of Mdm2, Akt, CDC2, Cyclin D, CXCR4, MAPKs. -- Abstract: Human umbilical cord mesenchymal stem cells (hUCMSCs) have been recently used in transplant therapy. The proliferation and migration of MSCs are the determinants of the efficiency of MSC transplant therapy. Sertoli cells are a kind of 'nurse' cells that support the development of sperm cells. Recent studies show that Sertoli cells promote proliferation of endothelial cells and neural stem cells in co-culture. We hypothesized that co-culture of UCMSCs with Sertoli cells may also promote proliferation and migration of UCMSCs. To examine this hypothesis, we isolated UCMSCs from human cords and Sertoli cells from mouse testes, and co-cultured them using a Transwell system. We found that UCMSCs exhibited strong proliferation ability and potential to differentiate to other cell lineages such as osteocytes and adipocytes. The presence of Sertoli cells in co-culture significantly enhanced the proliferation and migration potential of UCMSCs (P < 0.01). Moreover, these phenotypic changes were accompanied with upregulation of multiple genes involved in cell proliferation and migration including phospho-Akt, Mdm2, phospho-CDC2, Cyclin D1, Cyclin D3 as well as CXCR4, phospho-p44 MAPK and phospho-p38 MAPK. These findings indicate that Sertoli cells boost UCMSC proliferation and migration potential.
Wang, Bo; Lin, Zhiqiang; Wang, Min
Paper-based microfluidic devices (µPAD) are a burgeoning platform of microfluidic analysis technology. The method described herein is for use in undergraduate and high school chemistry laboratories. A simple and convenient µPAD was fabricated by easy patterning of filter paper using a permanent marker pen. The usefulness of the device was…
Bourdakos, Nicholas; Marsili, Enrico; Mahadevan, Radhakrishnan
Wastewater-fed microbial fuel cells (MFCs) are a promising technology to treat low-organic carbon wastewater and recover part of the chemical energy in wastewater as electrical power. However, the interactions between electrochemically active and fermentative microorganisms cannot be easily studied in wastewater-fed MFCs because of their complex microbial communities. Defined co-culture MFCs provide a detailed understanding of such interactions. In this study, we characterize the extracellular metabolites in laboratory-scale membrane-less MFCs inoculated with Geobacter sulfurreducens and Escherichia coli co-culture and compare them with pure culture MFCs. G. sulfurreducens MFCs are sparged to maintain anaerobic conditions, while co-culture MFCs rely on E. coli for oxygen removal. G. sulfurreducens MFCs have a power output of 128 mW m(-2) , compared to 63 mW m(-2) from the co-culture MFCs. Analysis of metabolites shows that succinate production in co-culture MFCs decreases current production by G. sulfurreducens and that the removal of succinate is responsible for the increased current density in the late co-culture MFCs. Interestingly, pH adjustment is not required for co-culture MFCs but a base addition is necessary for E. coli MFCs and cultures in vials. Our results show that defined co-culture MFCs provide clear insights into metabolic interactions among bacteria while maintaining a low operational complexity. © 2013 Wiley Periodicals, Inc.
Yoon, Sun Geun; Koo, Hyung-Jun; Chang, Suk Tai
We report a new class of simple microfluidic strain sensors with high stretchability, transparency, sensitivity, and long-term stability with no considerable hysteresis and a fast response to various deformations by combining the merits of microfluidic techniques and ionic liquids. The high optical transparency of the strain sensors was achieved by introducing refractive-index matched ionic liquids into microfluidic networks or channels embedded in an elastomeric matrix. The microfluidic strain sensors offer the outstanding sensor performance under a variety of deformations induced by stretching, bending, pressing, and twisting of the microfluidic strain sensors. The principle of our microfluidic strain sensor is explained by a theoretical model based on the elastic channel deformation. In order to demonstrate its capability of practical usage, the simple-structured microfluidic strain sensors were performed onto a finger, wrist, and arm. The highly stretchable and transparent microfluidic strain sensors were successfully applied as potential platforms for distinctively monitoring a wide range of human body motions in real time. Our novel microfluidic strain sensors show great promise for making future stretchable electronic devices.
Angelis, S; Novak, A C; Sydney, E B; Soccol, V T; Carvalho, J C; Pandey, A; Noseda, M D; Tholozan, J L; Lorquin, J; Soccol, C R
In this study, the biomass and exopolysaccharides (EPS) production in co-cultures of microalgae/cyanobacteria and macromycetes was evaluated as a technology for producing new polysaccharides for medical and/or industrial application. Based on biomass and EPS productivity of monocultures, two algae and two fungi were selected and cultured in different co-culture arrangements. The hydrosoluble EPS fractions from mono- and co-cultures were characterized by ¹³C NMR spectroscopy and gas chromatography coupled to mass spectrometry and compared. It was found that co-cultures resulted in the production of an EPS different from those produced by monocultures, showing fungal predominance with microalgal/cyanobacterial traces. Co-cultures conditions were screened (temperature, agitation speed, fungal and microalgae inoculation rate, initial pH, illumination rate, and glucose concentration) in order to achieve maximum biomass and EPS production, resulting in an increase of 33 and 61% in exopolysaccharides and biomass productions, respectively (patent pending).
Kanagasabapathi, Thirukumaran T; Massobrio, Paolo; Tedesco, Mariateresa; Martinoia, Sergio; Wadman, Wytse J; Decré, Michel M J
In this paper, we propose an experimental approach to develop an in vitro dissociated cortical-thalamic co-culture model using a dual compartment neurofluidic device. The device has two compartments separated by 10 μm wide and 3 μm high microchannels. The microchannels provide a physical isolation of neurons allowing only neurites to grow between the compartments. Long-term viable co-culture was maintained in the compartmented device, neurite growth through the microchannels was verified using immunofluorescence staining, and electrophysiological recordings from the co-culture system was investigated. Preliminary analysis of spontaneous activities from the co-culture shows a distinctively different firing pattern associated with cultures of individual cell types and further analysis is proposed for a deeper understanding of the dynamics involved in the network connectivity in such a co-culture system.
Copin, Pierre-Jean; Chèvre, Nathalie
A weakness of standard testing procedures is that they do not consider interactions between organisms, and they focus only on single species. Furthermore, these procedures do not take into account pulse exposure. However, pulse exposure is of particular importance because in streams, after crop application and during and after precipitation, herbicide concentrations fluctuate widely and can exceed the Annual Average Environmental Quality Standards (AA-EQS), which aim to protect the aquatic environment. The sensitivity of the algae Scenedesmus vacuolatus and Pseudokirchneriella subcapitata in a co-culture exposed to pulses is thus analysed in this study. As a first step, the growths of the algae in co-culture are investigated. For initial cell densities fixed, respectively, to 100,000 and 50,000 cells/mL, the growth of each alga is exponential over at least 48 h. S. vacuolatus seems to influence the growth of P. subcapitata negatively. Allelopathy is a possible explanation for this growth inhibition. The toxicity of the herbicide isoproturon is later tested on the algae S. vacuolatus and P. subcapitata cultured alone and in the co-culture. Despite the supplementary stress on the algae in the co-culture competing for nutrients, the toxicity of the herbicide is lower for the two algae when they are in the co-culture than when they are in separated culture. A model is adapted and used to predict the cell-density inhibition on the alga S. vacuolatus in the co-culture with the alga P. subcapitata exposed to a pulse concentration of isoproturon. Four laboratory experiments are performed to validate the model. The comparison between the laboratory and the modelled effects shows good agreement. The differences can be considered minor most of time. For future studies, it is important to ensure that the cell count is precise, as it is used to determine the parameters of the model. The differences can be also induced by the fact that the cell number of the alga P
Wang Wei; Yao Chen; Zhang Maojie; Ju Xiaojie; Xie Rui; Chu Liangyin
A novel thermo-driven microcrawler that can transform thermal stimuli into directional mechanical motion is developed by a simple microfluidic approach together with emulsion-template synthesis. The microcrawler is designed with a thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) hydrogel body and a bell-like structure with an eccentric cavity. The asymmetric shrinking–swelling circulation of the microcrawlers enables a thermo-driven locomotion responding to repeated temperature changes, which provides a novel model with symmetry breaking principle for designing biomimetic soft microrobots. The microfluidic approach offers a novel and promising platform for design and fabrication of biomimetic soft microrobots. (paper)
Nishimuta, James F; Bendernagel, Monica F; Levenston, Marc E
Although osteoarthritis is widely viewed as a disease of the whole joint, relatively few studies have focused on interactions among joint tissues in joint homeostasis and degeneration. In particular, few studies have examined the effects of the infrapatellar fat pad (IFP) on cartilaginous tissues. The aim of this study was to test the hypothesis that co-culture with healthy IFP would induce degradation of cartilage and meniscus tissues. Bovine articular cartilage, meniscus, and IFP were cultured isolated or as cartilage-fat or meniscus-fat co-cultures for up to 14 days. Conditioned media were assayed for sulfated glycosaminoglycan (sGAG) content, nitrite content, and matrix metalloproteinase (MMP) activity, and explants were assayed for sGAG and DNA contents. Co-cultures exhibited increased cumulative sGAG release and sGAG release rates for both cartilage and meniscus, and the cartilage (but not meniscus) exhibited a substantial synergistic effect of co-culture (sGAG release in co-culture was significantly greater than the summed release from isolated cartilage and fat). Fat co-culture did not significantly alter the sGAG content of either cartilage or meniscus explants, indicating that IFP co-culture stimulated net sGAG production by cartilage. Nitrite release was increased relative to isolated tissue controls in co-cultured meniscus, but not the cartilage, with no synergistic effect of co-culture. Interestingly, MMP-2 production was decreased by co-culture for both cartilage and meniscus. This study demonstrates that healthy IFP may modulate joint homeostasis by stimulating sGAG production in cartilage. Counter to our hypothesis, healthy IFP did not promote degradation of either cartilage or meniscus tissues.
Aijian, Andrew P; Garrell, Robin L
Cell spheroids are multicellular aggregates, grown in vitro, that mimic the three-dimensional morphology of physiological tissues. Although there are numerous benefits to using spheroids in cell-based assays, the adoption of spheroids in routine biomedical research has been limited, in part, by the tedious workflow associated with spheroid formation and analysis. Here we describe a digital microfluidic platform that has been developed to automate liquid-handling protocols for the formation, maintenance, and analysis of multicellular spheroids in hanging drop culture. We show that droplets of liquid can be added to and extracted from through-holes, or "wells," and fabricated in the bottom plate of a digital microfluidic device, enabling the formation and assaying of hanging drops. Using this digital microfluidic platform, spheroids of mouse mesenchymal stem cells were formed and maintained in situ for 72 h, exhibiting good viability (>90%) and size uniformity (% coefficient of variation <10% intraexperiment, <20% interexperiment). A proof-of-principle drug screen was performed on human colorectal adenocarcinoma spheroids to demonstrate the ability to recapitulate physiologically relevant phenomena such as insulin-induced drug resistance. With automatable and flexible liquid handling, and a wide range of in situ sample preparation and analysis capabilities, the digital microfluidic platform provides a viable tool for automating cell spheroid culture and analysis. © 2014 Society for Laboratory Automation and Screening.
Mungas, Gregory S. (Inventor); Fisher, David J. (Inventor); Mungas, Christopher (Inventor)
Propellants flow through specialized mechanical hardware that is designed for effective and safe ignition and sustained combustion of the propellants. By integrating a micro-fluidic porous media element between a propellant feed source and the combustion chamber, an effective and reliable propellant injector head may be implemented that is capable of withstanding transient combustion and detonation waves that commonly occur during an ignition event. The micro-fluidic porous media element is of specified porosity or porosity gradient selected to be appropriate for a given propellant. Additionally the propellant injector head design integrates a spark ignition mechanism that withstands extremely hot running conditions without noticeable spark mechanism degradation.
Chugh, Dipankar; Kaler, Karan V I S
Miniaturized fluidic systems have been developed in recent years and offer new and novel means of leveraging the domain of microfluidics for the development of micro-total analysis systems (μTAS). Initially, such systems employed closed microchannels in order to facilitate chip-based biochemical assays, requiring very small quantities of sample and/or reagents and furthermore providing rapid and low-cost analysis on a compact footprint. More recently, advancements in the domain of surface microfluidics have suggested that similar low volume sample handling and manipulation capabilities for bioassays can be attained by leveraging the phenomena of liquid dielectrophoresis and droplet dielectrophoresis (DEP), without the need for separate pumps or valves. Some of the key aspects of this surface microfluidic technology and its capabilities are discussed and highlighted in this paper. We, furthermore, examine the integration and utility of liquid DEP and droplet DEP in providing rapid and automated sample handling and manipulation capabilities on a compact chip-based platform
Siew-Wan, Ohl; Tandiono; Klaseboer, Evert; Dave, Ow; Choo, Andre; Claus-Dieter, Ohl
This study reports the technical breakthrough in generating intense ultrasonic cavitation in the confinement of a microfluidics channel , and applications that has been developed on this platform for the past few years [2,3,4,5]. Our system consists of circular disc transducers (10-20 mm in diameter), the microfluidics channels on PDMS (polydimethylsiloxane), and a driving circuitry. The cavitation bubbles are created at the gas- water interface due to strong capillary waves which are generated when the system is driven at its natural frequency (around 100 kHz) . These bubbles oscillate and collapse within the channel. The bubbles are useful for sonochemistry and the generation of sonoluminescence . When we add bacteria (Escherichia coli), and yeast cells (Pichia pastoris) into the microfluidics channels, the oscillating and collapsing bubbles stretch and lyse these cells . Furthermore, the system is effective (DNA of the harvested intracellular content remains largely intact), and efficient (yield reaches saturation in less than 1 second). In another application, human red blood cells are added to a microchamber. Cell stretching and rapture are observed when a laser generated cavitation bubble expands and collapses next to the cell . A numerical model of a liquid pocket surrounded by a membrane with surface tension which was placed next to an oscillating bubble was developed using the Boundary Element Method. The simulation results showed that the stretching of the liquid pocket occurs only when the surface tension is within a certain range. (paper)
Yeung, Tracey; Kwan, Matthew; Adler, Lewis; Mills, Toby J; Neilan, Brett A; Conibeer, Gavin; Patterson, Robert
A novel light-to-bioenergy system produced 3.5 times the baseline methane output using a co-culture of cyanobacteria (Oscillatoria sp.) and a methanogenic microbial community. Analysis of micronutrients in the system during the growth phase indicated that cobalt, iron, nickel and zinc were not appreciably consumed. The stable consumption and return of macronutrients calcium and magnesium were also observed. Essential macronutrients nitrogen, in the form of nitrate, and phosphorus showed no cycling during the growth phase and were depleted at rates of 0.35mg/L/day and 0.40µg/L/day, respectively. Biofilm formation increased the resilience of biomass to bacterial degradation in an anaerobic digester, as shown by viability assays of cyanobacterial biofilms in the co-culture. Copyright © 2017 Elsevier Ltd. All rights reserved.
Nielsen, Line Hagner; De Rossi, C.; Lehr, C.-M.
the immunostimulatory ability of particulate vaccine formulations designed for oral delivery. Levels of cytokine production in response to vaccine administration were measured following particulate vaccine administration, as an indication of dendritic cell and macrophage activation. Precursors of cubosomes containing......; this was not observed with ovalbumin and blank solution. An example of the results is shown in Figure 2 for IL-17A. An established co-culture of Caco-2, THP-1 and MUTZ-3 cells showed promise as an in vitro model for testing of oral vaccine formulations. Mobility of co-culture immune cells as well as cytokine production...... with particle formulations. This was not the case when incubating with ovalbumin solution or blank. The ELISA screening assay showed production of a wide range of cytokines following culture incubation with cubosomes (with and without ovalbumin) and LPS solutions, indicative of a stimulatory effect...
Kolbman, Dan; Das, Moumita
The biophysics of binary cell populations is of great interest in many biological processes, whether the formation of embryos or the initiation of tumors. During these processes, cells are surrounded by other cell types with different physical properties, often with important consequences. For example, recent experiments on a co-culture of breast cancer cells and healthy breast epithelial cells suggest that the mechanical mismatch between the two cell types may contribute to enhanced migration of the cancer cells. Here we explore how the differential physical properties of different cell types may influence cell-cell interaction, aggregation, and migration. To this end, we study a proof of concept model- a three-dimensional binary system of interacting, active, and deformable particles with different physical properties such as elastic stiffness, contractility, and particle-particle adhesion, using Langevin Dynamics simulations. Our results may provide insights into emergent behavior such as segregation and differential migration in cell co-cultures in three dimensions.
Wang, Zhibing; Zhang, Xia; Guo, Xinyu; Qin, Chuan
To investigate the preparation of decellularized Achilles tendons and the effect of co-culture of human fibroblasts on the scaffold so as to provide a scaffold for the tissue engineered ligament reconstruction. Achilles tendons of both hind limbs were harvested from 10 male New Zealand white rabbits (5-month-old; weighing, 4-5 kg). The Achilles tendons were decellularized using trypsin, Triton X-100, and sodium dodecyl sulfate (SDS), and then gross observation, histological examination, and scanning electron microscope (SEM) observation were performed; the human fibroblasts were seeded on the decellularized Achilles tendon, and then cytocompatibility was tested using the cell counting kit 8 method at 1, 3, 5, 7, and 9 days after co-culture. At 4 weeks after co-culture, SEM, HE staining, and biomechanical test were performed for observing cell-scaffold composite, and a comparison was made with before and after decellularization. After decellularization, the tendons had integrated aponeurosis and enlarged volume with soft texture and good toughness; there was no loose connective tissue and tendon cells between tendon bundles, the collagen fibers arranged loosely with three-dimensional network structure and more pores between tendon bundles; and it had good cytocompatibility. At 4 weeks after co-culture, cells migrated into the pores, and three-dimensional network structure disappeared. By biomechanical test, the tensile strength and Young's elastic modulus of the decellularized Achilles tendon group decreased significantly when compared with normal Achilles tendons group and cell-scaffold composite group (P Achilles tendons group and cell-scaffold composite group (P > 0.05). There was no significant difference in elongation at break among 3 groups (P > 0.05). The decellularized Achilles tendon is biocompatible to fibroblasts. It is suit for the scaffold for tissue engineered ligament reconstruction.
O'Mullane, Lauren M; Keast, Janet R; Osborne, Peregrine B
Recent evidence suggests that the urothelium functions as a sensory transducer of chemical, mechanical or thermal stimuli and signals to nerve terminals and other cells in the bladder wall. The cellular and molecular basis of neuro-urothelial communication is not easily studied in the intact bladder. This led us to establish a method of co-culturing dorsal root ganglion sensory neurons and bladder urothelial cells. Sensory neurons and urothelial cells obtained from dorsal root ganglia and bladders dissected from adult female Sprague-Dawley® rats were isolated by enzyme treatment and mechanical dissociation. They were plated together or separately on collagen coated substrate and cultured in keratinocyte medium for 48 to 72 hours. Retrograde tracer labeling was performed to identify bladder afferents used for functional testing. Neurite growth and complexity in neurons co-cultured with urothelial cells was increased relative to that in neuronal monocultures. The growth promoting effect of urothelial cells was reduced by the tyrosine kinase inhibitor K252a but upstream inhibition of nerve growth factor signaling with TrkA-Fc had no effect. Fura-2 calcium imaging of urothelial cells showed responses to adenosine triphosphate (100 μM) and activation of TRPV4 (4α-PDD, 10 μM) but not TRPV1 (capsaicin, 1 μM), TRPV3 (farnesyl pyrophosphate, 1 μM) or TRPA1 (mustard oil, 100 μM). In contrast, co-cultured neurons were activated by all agonists except farnesyl pyrophosphate. Co-culturing provides a new methodology for investigating neuro-urothelial interactions in animal models of urological conditions. Results suggest that neuronal properties are maintained in the presence of urothelium and neurite growth is potentiated by a nerve growth factor independent mechanism. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
Choi, Hyuck; Myung, Kyuho
We have conducted an in vitro experiment to determine whether calcitriol can act as a fat synthesizer and/or meat tenderizer when skeletal muscle cells, adipose tissue, and macrophages are co-cultured. When co-cultured, pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) expression increased, whereas decreased anti-inflammatory cytokine (IL-10 and IL-15) expression decreased in both C2C12 and 3T3-L1 cells. Calcitriol increased reactive oxygen species (ROS) production in the media. While adiponectin gene expression decreased, leptin, resistin, CCAAT-enhancer-binding protein-beta (C/EBP-β), and peroxisome proliferator-activated receptor gamma (PPAR-γ) gene expression was significantly (P cultured with two different cell types. Inducible nitric oxide synthase (iNOS) protein levels were also stimulated in the C2C12 and 3T3-L1 cells, but arginase l was attenuated by calcitriol. Cacitriol highly amplified (P = 0.008) µ-calpain gene expression in co-cultured C2C12 cells. The results showed an overall increase in pro-inflammatory cytokines and a decrease in anti-inflammatory cytokines of C2C12 and 3T3-L1 cells with calcitriol in co-culture systems. µ-Calpain protein was also augmented in differentiated C2C12 cells with calcitriol. These findings suggest that calcitriol can be used as not only fat synthesizer, but meat tenderizer, in meat-producing animals. © 2014 International Federation for Cell Biology.
Zhang, Bo; Yang, Yunfeng; Tang, Jun; Tao, Yihao; Jiang, Bing; Chen, Zhi; Feng, Hua; Yang, Liming; Zhu, Gang
The objective of this study is to establish a co-culture model of mouse neurons and microglial cells, and to analyze the mechanism of action of oxygen glucose deprivation (OGD) and transient oxygen glucose deprivation (tOGD) preconditioning cell models. Mouse primary neurons and BV2 microglial cells were successfully cultured, and the OGD and tOGD models were also established. In the co-culture of mouse primary neurons and microglial cells, the cell number of tOGD mouse neurons and microglial cells was larger than the OGD cell number, observed by a microscope. CCK-8 assay result showed that at 1h after treatment, the OD value in the control group is lower compared to all the other three groups (P control group compared to other three groups (P neurons cells were cultured. In the meantime mouse BV2 microglia cells were cultured. Two types of cells were co-cultured, and OGD and tOGD cell models were established. There were four groups in the experiment: control group (OGD), treatment group (tOGD+OGD), placebo group (tOGD+OGD+saline) and minocycline intervention group (tOGD+OGD+minocycline). CCK-8 kit was used to detect cell viability and flow cytometry was used to detect apoptosis. In this study, mouse primary neurons and microglial cells were co-cultured. The OGD and tOGD models were established successfully. tOGD was able to effectively protect neurons and microglial cells from damage, and inhibit the apoptosis caused by oxygen glucose deprivation.
Guo, Shuangsheng; Ai, Weidang; Tang, Yongkang; Cheng, Quanyong; Shen, Yunze; Qin, Lifeng; Ma, Jialu; Zhu, Jingtao; Ren, Jin
The ability to generate O2 and absorb CO2 of several co-cultured vegetable plants in an enclosed system was studied to provide theoretical reference for the future man-plant integrated tests. Four kinds of salad plants (Lactuca sativa L. var. Dasusheng, Lactuca sativa L. var. Youmaicai, Gynura bicolor and Cichorium endivia L.) were grown in the CELSS Integration Test Platform (CITP). The environmental factors including O2 and CO2 concentration were continuously monitored on-line and the plant biomass was measured at the end of the test. The changing rules of O2 and CO2 concentration in the system were basically understood and it was found that the O2 generated by the plants could satisfy the respiratory needs of 1.75 persons by calculation. It was also found that the plants could absorb the CO2 breathed out by 2 persons when the light intensity was raised to 550 mmol m-2 s-1 PPF. The results showed that the co-cultured plants hold good compatibility and excellent O2-generating and CO2-absorbing capability. They could also supply some fresh edible vegetable for a 2-person crew.
Berry, Samuel B; Zhang, Tianzi; Day, John H; Su, Xiaojing; Wilson, Ilham Z; Berthier, Erwin; Theberge, Ashleigh B
Cellular communication between multiple cell types is a ubiquitous process that is responsible for vital physiological responses observed in vivo (e.g., immune response, organ function). Many in vitro coculture strategies have been developed, both in traditional culture and microscale systems, and have shown the potential to recreate some of the physiological behaviors of organs or groups of cells. A fundamental limitation of current systems is the difficulty of reconciling the additional engineering requirements for creating soluble factor signaling systems (e.g., segregated cell culture) with the use of well-characterized materials and platforms that have demonstrated successful results and biocompatibility in assays. We present a new open-microfluidic platform, the Monorail Device, that is placed in any existing well plate or Petri dish and enables patterning of segregated coculture regions, thereby allowing the direct upgrade of monoculture experiments into multiculture assays. Our platform patterns biocompatible hydrogel walls via microfluidic spontaneous capillary flow (SCF) along a rail insert set inside commercially available cultureware, creating customized pipette-accessible cell culture chambers that require fewer cells than standard macroscale culture. Importantly, the device allows the use of native surfaces without additional modification or treatments, while creating permeable dividers for the diffusion of soluble factors. Additionally, the ease of patterning afforded by our platform makes reconfiguration of the culture region as simple as changing the rail insert. We demonstrate the ability of the device to pattern flows on a variety of cell culture surfaces and create hydrogel walls in complex and precise shapes. We characterize the physical parameters that enable a reproducible SCF-driven flow and highlight specialized design features that increase the ease of use of the device and control of the open microfluidic flow. Further, we present the
Eleftherios H. Drosinos
Full Text Available The aim of the present study was to assess the expression of key virulence genes during co-culture of L. monocytogenes with a bacteriocinogenic E. faecium strain in liquid growth medium. For that purpose, BHI broth was inoculated with 7 log CFU·mL–1 L. monocytogenes and 4, 5 or 6 log CFU·mL–1 E. faecium. Sampling took place after 8 and 24 h of incubation, corresponding to the maximum and minimum of enterocin production, respectively. The RNA was extracted, stabilized and expression of prfA, sigB, hly, plcA, plcB, inlA, inlB, inlC and inlJ, was assessed by RT-qPCR. Most of the genes were downregulated during co-culture at 5 °C. Moreover, a statistically significant effect of the inoculum level was evident in most of the cases. On the contrary, no effect on the transcription level of most of the genes was observed during co-culture at 37 °C.
Kuss, Mitchell A; Wu, Shaohua; Wang, Ying; Untrauer, Jason B; Li, Wenlong; Lim, Jung Yul; Duan, Bin
Vascularization is a fundamental prerequisite for large bone construct development and remains one of the main challenges of bone tissue engineering. Our current study presents the combination of 3D printing technique with a hydrogel-based prevascularization strategy to generate prevascularized bone constructs. Human adipose derived mesenchymal stem cells (ADMSC) and human umbilical vein endothelial cells (HUVEC) were encapsulated within our bioactive hydrogels, and the effects of culture conditions on in vitro vascularization were determined. We further generated composite constructs by forming 3D printed polycaprolactone/hydroxyapatite scaffolds coated with cell-laden hydrogels and determined how the co-culture affected vascularization and osteogenesis. It was demonstrated that 3D co-cultured ADMSC-HUVEC generated capillary-like networks within the porous 3D printed scaffold. The co-culture systems promoted in vitro vascularization, but had no significant effects on osteogenesis. The prevascularized constructs were subcutaneously implanted into nude mice to evaluate the in vivo vascularization capacity and the functionality of engineered vessels. The hydrogel systems facilitated microvessel and lumen formation and promoted anastomosis of vascular networks of human origin with host murine vasculature. These findings demonstrate the potential of prevascularized 3D printed scaffolds with anatomical shape for the healing of larger bone defects. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.
Jeliazkova-Mecheva, Valentina V; Bobilya, Dennis J
A method for the isolation of porcine atrocytes as a simple extension of a previously described procedure for isolation of brain capillary endothelial cells from adolescent pigs [Methods Cell Sci. 17 (1995) 2] is described. The obtained astroglial culture purified through two passages and by the method of the selective detachment was validated by a phase contrast microscopy and through an immunofluorescent assay for the glial fibrillary acidic protein (GFAP). Porcine astrocytes were co-cultivated with porcine brain capillary endothelial cells (PBCEC) for the development of an in vitro blood-brain barrier (BBB) model. The model was visualized by an electron microscopy and showed elevated transendothellial electrical resistance and reduced inulin permeability. To our knowledge, this is the first report for the establishment of a porcine astrocyte/endothelial cell co-culture BBB model, which avoids interspecies and age differences between the two cell types, usually encountered in the other reported co-culture BBB models. Considering the availability of the porcine brain tissue and the close physiological and anatomical relation between the human and pig brain, the porcine astrocyte/endothelial cell co-culture system can serve as a reliable and easily reproducible model for different in vitro BBB studies.
Correia, Clara R.; Pirraco, Rogério P.; Cerqueira, Mariana T.; Marques, Alexandra P.; Reis, Rui L.; Mano, João F.
A new concept of semipermeable reservoirs containing co-cultures of cells and supporting microparticles is presented, inspired by the multi-phenotypic cellular environment of bone. Based on the deconstruction of the “stem cell niche”, the developed capsules are designed to drive a self-regulated osteogenesis. PLLA microparticles functionalized with collagen I, and a co-culture of adipose stem (ASCs) and endothelial (ECs) cells are immobilized in spherical liquified capsules. The capsules are coated with multilayers of poly(L-lysine), alginate, and chitosan nano-assembled through layer-by-layer. Capsules encapsulating ASCs alone or in a co-culture with ECs are cultured in endothelial medium with or without osteogenic differentiation factors. Results show that osteogenesis is enhanced by the co-encapsulation, which occurs even in the absence of differentiation factors. These findings are supported by an increased ALP activity and matrix mineralization, osteopontin detection, and the up regulation of BMP-2, RUNX2 and BSP. The liquified co-capsules also act as a VEGF and BMP-2 cytokines release system. The proposed liquified capsules might be a valuable injectable self-regulated system for bone regeneration employing highly translational cell sources.
Jensen, Kristian Ejlebjærg
Numerical modelling can illuminate the working mechanism and limitations of microfluidic devices. Such insights are useful in their own right, but one can take advantage of numerical modelling in a systematic way using numerical optimization. In this chapter we will discuss when and how numerical...... optimization is best used....
Microfluidic-implemented methods of detecting an enzyme, in particular a DNA-modifying enzyme, are provided, as well as methods for detecting a cell, or a microorganism expressing said enzyme. The enzyme is detected by providing a nucleic acid substrate, which is specifically targeted...... by that enzyme...
van den Berg, Albert; van den Berg, A.; Segerink, L.I.; Segerink, Loes Irene; Unknown, [Unknown
Lab-on-a-chip devices for point of care diagnostics have been present in clinics for several years now. Alongside their continual development, research is underway to bring the organs and tissue on-a-chip to the patient, amongst other medical applications of microfluidics. This book provides the
Chia, Matthew C.; Sweeney, Christina M.; Odom, Teri W.
General chemistry introduces principles such as acid-base chemistry, mixing, and precipitation that are usually demonstrated in bulk solutions. In this laboratory experiment, we describe how chemical reactions can be performed in a microfluidic channel to show advanced concepts such as laminar fluid flow and controlled precipitation. Three sets of…
Smejkal, P.; Bottenus, D.; Breadmore, M. C.; Guijt, R. M.; Ivory, C. F.; Foret, František; Macka, M.
Roč. 34, č. 11 (2013), s. 1493-1509 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GAP301/11/2055 Institutional support: RVO:68081715 Keywords : chip * isotachophoresis * microfluidics * miniaturization Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.161, year: 2013
Lee, Hun; Xu, Linfeng; Koh, Domin; Nyayapathi, Nikhila; Oh, Kwang W
In this paper, we review recent advances in on-chip sensors integrated with microfluidics for biological applications. Since the 1990s, much research has concentrated on developing a sensing system using optical phenomena such as surface plasmon resonance (SPR) and surface-enhanced Raman scattering (SERS) to improve the sensitivity of the device. The sensing performance can be significantly enhanced with the use of microfluidic chips to provide effective liquid manipulation and greater flexibility. We describe an optical image sensor with a simpler platform for better performance over a larger field of view (FOV) and greater depth of field (DOF). As a new trend, we review consumer electronics such as smart phones, tablets, Google glasses, etc. which are being incorporated in point-of-care (POC) testing systems. In addition, we discuss in detail the current optical sensing system integrated with a microfluidic chip.
Full Text Available In this paper, we review recent advances in on-chip sensors integrated with microfluidics for biological applications. Since the 1990s, much research has concentrated on developing a sensing system using optical phenomena such as surface plasmon resonance (SPR and surface-enhanced Raman scattering (SERS to improve the sensitivity of the device. The sensing performance can be significantly enhanced with the use of microfluidic chips to provide effective liquid manipulation and greater flexibility. We describe an optical image sensor with a simpler platform for better performance over a larger field of view (FOV and greater depth of field (DOF. As a new trend, we review consumer electronics such as smart phones, tablets, Google glasses, etc. which are being incorporated in point-of-care (POC testing systems. In addition, we discuss in detail the current optical sensing system integrated with a microfluidic chip.
Sebastian, Bernhard; Dittrich, Petra S.
Throughout history, capillary systems have aided the establishment of the fundamental laws of blood flow and its non-Newtonian properties. The advent of microfluidics technology in the 1990s propelled the development of highly integrated lab-on-a-chip platforms that allow highly accurate replication of vascular systems' dimensions, mechanical properties, and biological complexity. Applications include the detection of pathological changes to red blood cells, white blood cells, and platelets at unparalleled sensitivity and the efficacy assessment of drug treatment. Recent efforts have aimed at the development of microfluidics-based tests usable in a clinial environment or the replication of more complex diseases such as thrombosis. These microfluidic disease models enable the study of onset and progression of disease as well as the identification of key players and risk factors, which have led to a spectrum of clinically relevant findings.
Andersson, Martin; Ek, Johan; Hedman, Ludvig; Johansson, Fredrik; Sehlstedt, Viktor; Stocklassa, Jesper; Snögren, Pär; Pettersson, Victor; Larsson, Jonas; Vizuete, Olivier; Hjort, Klas; Klintberg, Lena
High-pressure microfluidics offers fast analyses of thermodynamic parameters for compressed process solvents. However, microfluidic platforms handling highly compressible supercritical CO 2 are difficult to control, and on-chip sensing would offer added control of the devices. Therefore, there is a need to integrate sensors into highly pressure tolerant glass chips. In this paper, thin film Pt sensors were embedded in shallow etched trenches in a glass wafer that was bonded with another glass wafer having microfluidic channels. The devices having sensors integrated into the flow channels sustained pressures up to 220 bar, typical for the operation of supercritical CO 2 . No leakage from the devices could be found. Integrated temperature sensors were capable of measuring local decompression cooling effects and integrated calorimetric sensors measured flow velocities over the range 0.5–13.8 mm s −1 . By this, a better control of high-pressure microfluidic platforms has been achieved. (paper)
Alapan, Yunus; Hasan, Muhammad Noman; Shen, Richang; Gurkan, Umut A
Microfluidic platforms offer revolutionary and practical solutions to challenging problems in biology and medicine. Even though traditional micro/nanofabrication technologies expedited the emergence of the microfluidics field, recent advances in advanced additive manufacturing hold significant potential for single-step, stand-alone microfluidic device fabrication. One such technology, which holds a significant promise for next generation microsystem fabrication is three-dimensional (3D) printing. Presently, building 3D printed stand-alone microfluidic devices with fully embedded microchannels for applications in biology and medicine has the following challenges: (i) limitations in achievable design complexity, (ii) need for a wider variety of transparent materials, (iii) limited z-resolution, (iv) absence of extremely smooth surface finish, and (v) limitations in precision fabrication of hollow and void sections with extremely high surface area to volume ratio. We developed a new way to fabricate stand-alone microfluidic devices with integrated manifolds and embedded microchannels by utilizing a 3D printing and laser micromachined lamination based hybrid manufacturing approach. In this new fabrication method, we exploit the minimized fabrication steps enabled by 3D printing, and reduced assembly complexities facilitated by laser micromachined lamination method. The new hybrid fabrication method enables key features for advanced microfluidic system architecture: (i) increased design complexity in 3D, (ii) improved control over microflow behavior in all three directions and in multiple layers, (iii) transverse multilayer flow and precisely integrated flow distribution, and (iv) enhanced transparency for high resolution imaging and analysis. Hybrid manufacturing approaches hold great potential in advancing microfluidic device fabrication in terms of standardization, fast production, and user-independent manufacturing.
Kumar, Suveen; Kumar, Saurabh; Ali, Md Azahar; Anand, Pinki; Agrawal, Ved Varun; John, Renu; Maji, Sagar; Malhotra, Bansi D
There is a growing demand to integrate biosensors with microfluidics to provide miniaturized platforms with many favorable properties, such as reduced sample volume, decreased processing time, low cost analysis and low reagent consumption. These microfluidics-integrated biosensors would also have numerous advantages such as laminar flow, minimal handling of hazardous materials, multiple sample detection in parallel, portability and versatility in design. Microfluidics involves the science and technology of manipulation of fluids at the micro- to nano-liter level. It is predicted that combining biosensors with microfluidic chips will yield enhanced analytical capability, and widen the possibilities for applications in clinical diagnostics. The recent developments in microfluidics have helped researchers working in industries and educational institutes to adopt some of these platforms for point-of-care (POC) diagnostics. This review focuses on the latest advancements in the fields of microfluidic biosensing technologies, and on the challenges and possible solutions for translation of this technology for POC diagnostic applications. We also discuss the fabrication techniques required for developing microfluidic-integrated biosensors, recently reported biomarkers, and the prospects of POC diagnostics in the medical industry. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Karimi, Mahdi; Bahrami, Sajad; Mirshekari, Hamed; Basri, Seyed Masoud Moosavi; Nik, Amirala Bakhshian; Aref, Amir R; Akbari, Mohsen; Hamblin, Michael R
Neural tissue engineering aims at developing novel approaches for the treatment of diseases of the nervous system, by providing a permissive environment for the growth and differentiation of neural cells. Three-dimensional (3D) cell culture systems provide a closer biomimetic environment, and promote better cell differentiation and improved cell function, than could be achieved by conventional two-dimensional (2D) culture systems. With the recent advances in the discovery and introduction of different types of stem cells for tissue engineering, microfluidic platforms have provided an improved microenvironment for the 3D-culture of stem cells. Microfluidic systems can provide more precise control over the spatiotemporal distribution of chemical and physical cues at the cellular level compared to traditional systems. Various microsystems have been designed and fabricated for the purpose of neural tissue engineering. Enhanced neural migration and differentiation, and monitoring of these processes, as well as understanding the behavior of stem cells and their microenvironment have been obtained through application of different microfluidic-based stem cell culture and tissue engineering techniques. As the technology advances it may be possible to construct a "brain-on-a-chip". In this review, we describe the basics of stem cells and tissue engineering as well as microfluidics-based tissue engineering approaches. We review recent testing of various microfluidic approaches for stem cell-based neural tissue engineering.
Brian F. Bender
Full Text Available Digital (droplet microfluidics (DµF is a powerful platform for automated lab-on-a-chip procedures, ranging from quantitative bioassays such as RT-qPCR to complete mammalian cell culturing. The simple MEMS processing protocols typically employed to fabricate DµF devices limit their functionality to two dimensions, and hence constrain the applications for which these devices can be used. This paper describes the integration of vertical functionality into a DµF platform by stacking two planar digital microfluidic devices, altering the electrode fabrication process, and incorporating channels for reversibly translating droplets between layers. Vertical droplet movement was modeled to advance the device design, and three applications that were previously unachievable using a conventional format are demonstrated: (1 solutions of calcium dichloride and sodium alginate were vertically mixed to produce a hydrogel with a radially symmetric gradient in crosslink density; (2 a calcium alginate hydrogel was formed within the through-well to create a particle sieve for filtering suspensions passed from one layer to the next; and (3 a cell spheroid formed using an on-chip hanging-drop was retrieved for use in downstream processing. The general capability of vertically delivering droplets between multiple stacked levels represents a processing innovation that increases DµF functionality and has many potential applications.
Wong, Eric W. (Inventor)
A method of making a microfluidic device is provided. The method features patterning a permeable wall on a substrate, and surrounding the permeable wall with a solid, non-permeable boundary structure to establish a microfluidic channel having a cross-sectional dimension less than 5,000 microns and a cross-sectional area at least partially filled with the permeable wall so that fluid flowing through the microfluidic channel at least partially passes through the permeable wall.
Meyer, M T; Bentley, W E; Ghodssi, R; Subramanian, S; Kim, Y W; Ben-Yoav, H; Gnerlich, M; Gerasopoulos, K
Bacterial biofilms present a societal challenge, as they occur in the majority of infections but are highly resistant to both immune mechanisms and traditional antibiotics. In the pursuit of better understanding biofilm biology for developing new treatments, there is a need for streamlined, controlled platforms for biofilm growth and evaluation. We leverage advantages of microfluidics to develop a system in which biofilms are formed and sectioned, allowing parallel assays on multiple sections of one biofilm. A microfluidic testbed with multiple depth profiles was developed to accommodate biofilm growth and sectioning by hydraulically actuated valves. In realization of the platform, a novel fabrication technique was developed for creating multi-depth microfluidic molds using sequentially patterned photoresist separated and passivated by conformal coatings using atomic layer deposition. Biofilm thickness variation within three separately tested devices was less than 13% of the average thickness in each device, while variation between devices was 23% of the average thickness. In a demonstration of parallel experiments performed on one biofilm within one device, integrated valves were used to trisect the uniform biofilms with one section maintained as a control, and two sections exposed to different concentrations of sodium dodecyl sulfate. The technology presented here for multi-depth microchannel fabrication can be used to create a host of microfluidic devices with diverse architectures. While this work focuses on one application of such a device in biofilm sectioning for parallel experimentation, the tailored architectures enabled by the fabrication technology can be used to create devices that provide new biological information. (paper)
Meyer, M. T.; Subramanian, S.; Kim, Y. W.; Ben-Yoav, H.; Gnerlich, M.; Gerasopoulos, K.; Bentley, W. E.; Ghodssi, R.
Bacterial biofilms present a societal challenge, as they occur in the majority of infections but are highly resistant to both immune mechanisms and traditional antibiotics. In the pursuit of better understanding biofilm biology for developing new treatments, there is a need for streamlined, controlled platforms for biofilm growth and evaluation. We leverage advantages of microfluidics to develop a system in which biofilms are formed and sectioned, allowing parallel assays on multiple sections of one biofilm. A microfluidic testbed with multiple depth profiles was developed to accommodate biofilm growth and sectioning by hydraulically actuated valves. In realization of the platform, a novel fabrication technique was developed for creating multi-depth microfluidic molds using sequentially patterned photoresist separated and passivated by conformal coatings using atomic layer deposition. Biofilm thickness variation within three separately tested devices was less than 13% of the average thickness in each device, while variation between devices was 23% of the average thickness. In a demonstration of parallel experiments performed on one biofilm within one device, integrated valves were used to trisect the uniform biofilms with one section maintained as a control, and two sections exposed to different concentrations of sodium dodecyl sulfate. The technology presented here for multi-depth microchannel fabrication can be used to create a host of microfluidic devices with diverse architectures. While this work focuses on one application of such a device in biofilm sectioning for parallel experimentation, the tailored architectures enabled by the fabrication technology can be used to create devices that provide new biological information.
Microfluidics has advanced in terms of designs and structures, however, fabrication methods are either time consuming or expensive to produce, in terms of the facilities and equipment needed. A fast and economically viable method is provided to allow, for example, research groups to have access to microfluidic fabrication. Unlike most fabrication methods, a method is provided to fabricate a microfluidic device in one step. In an embodiment, a resolution of 50 micrometers was achieved by using maskless high-resolution digital light projection (MDLP). Bonding and channel fabrication of complex or simple structures can be rapidly incorporated to fabricate the microfluidic devices.
Tan, Say Hwa; Maes, Florine; Semin, Benoît; Vrignon, Jérémy; Baret, Jean-Christophe
Music is a form of art interweaving people of all walks of life. Through subtle changes in frequencies, a succession of musical notes forms a melody which is capable of mesmerizing the minds of people. With the advances in technology, we are now able to generate music electronically without relying solely on physical instruments. Here, we demonstrate a musical interpretation of droplet-based microfluidics as a form of novel electronic musical instruments. Using the interplay of electric field and hydrodynamics in microfluidic devices, well controlled frequency patterns corresponding to musical tracks are generated in real time. This high-speed modulation of droplet frequency (and therefore of droplet sizes) may also provide solutions that reconciles high-throughput droplet production and the control of individual droplet at production which is needed for many biochemical or material synthesis applications.
Lee, Jin Wook; Goulet, Marc-Antoni; Kjeang, Erik
A miniaturized microfluidic battery is proposed, which is the first membraneless redox battery demonstrated to date. This unique concept capitalizes on dual-pass flow-through porous electrodes combined with stratified, co-laminar flow to generate electrical power on-chip. The fluidic design is symmetric to allow for both charging and discharging operations in forward, reverse, and recirculation modes. The proof-of-concept device fabricated using low-cost materials integrated in a microfluidic chip is shown to produce competitive power levels when operated on a vanadium redox electrolyte. A complete charge/discharge cycle is performed to demonstrate its operation as a rechargeable battery, which is an important step towards providing sustainable power to lab-on-a-chip and microelectronic applications.
Owida, H A; De Las Heras Ruiz, T; Dhillon, A; Yang, Y; Kuiper, N J
Adult articular chondrocytes are surrounded by a pericellular matrix (PCM) to form a chondron. The PCM is rich in hyaluronan, proteoglycans, and collagen II, and it is the exclusive location of collagen VI in articular cartilage. Collagen VI anchors the chondrocyte to the PCM. It has been suggested that co-culture of chondrons with mesenchymal stromal cells (MSCs) might enhance extracellular matrix (ECM) production. This co-culture study investigates whether MSCs help to preserve the PCM and increase ECM production. Primary bovine chondrons or chondrocytes or rat MSCs were cultured alone to establish a baseline level for ECM production. A xenogeneic co-culture monolayer model using rat MSCs (20, 50, and 80%) was established. PCM maintenance and ECM production were assessed by biochemical assays, immunofluorescence, and histological staining. Co-culture of MSCs with chondrons enhanced ECM matrix production, as compared to chondrocyte or chondron only cultures. The ratio 50:50 co-culture of MSCs and chondrons resulted in the highest increase in GAG production (18.5 ± 0.54 pg/cell at day 1 and 11 ± 0.38 pg/cell at day 7 in 50:50 co-culture versus 16.8 ± 0.61 pg/cell at day 1 and 10 ± 0.45 pg/cell at day 7 in chondron monoculture). The co-culture of MSCs with chondrons appeared to decelerate the loss of the PCM as determined by collagen VI expression, whilst the expression of high-temperature requirement serine protease A1 (HtrA1) demonstrated an inverse relationship to that of the collagen VI. Together, this implies that MSCs directly or indirectly inhibited HtrA1 activity and the co-culture of MSCs with chondrons enhanced ECM synthesis and the preservation of the PCM.
As humans prepare for the exploration of our solar system, there is a growing need for miniaturized medical and environmental diagnostic devices for use on spacecrafts, especially during long-duration space missions where size and power requirements are critical. In recent years, the biochip (or Lab-on-a- Chip) has emerged as a technology that might be able to satisfy this need. In generic terms, a biochip is a miniaturized microfluidic device analogous to the electronic microchip that ushered in the digital age. It consists of tiny microfluidic channels, pumps and valves that transport small amounts of sample fluids to biosensors that can perform a variety of tests on those fluids in near real time. It has the obvious advantages of being small, lightweight, requiring less sample fluids and reagents and being more sensitive and efficient than larger devices currently in use. Some of the desired space-based applications would be to provide smaller, more robust devices for analyzing blood, saliva and urine and for testing water and food supplies for the presence of harmful contaminants and microorganisms. Our group has undertaken the goal of adapting as well as improving upon current biochip technology for use in long-duration microgravity environments. In addition to developing computational models of the microfluidic channels, valves and pumps that form the basis of every biochip, we are also trying to identify potential problems that could arise in reduced gravity and develop solutions to these problems. One such problem is due to the prevalence of bubbly sample fluids in microgravity. A bubble trapped in a microfluidic channel could be detrimental to the operation of a biochip. Therefore, the process of bubble formation in microgravity needs to be studied, and a model of this process has been developed and used to understand how bubbles develop and move through biochip components. It is clear that some type of bubble filter would be necessary in Space, and
Palethorpe, Helen M; Leach, Damien A; Need, Eleanor F; Drew, Paul A; Smith, Eric
Fibroblasts express androgen receptor (AR) in the normal prostate and during prostate cancer development. We have reported that loss of AR expression in prostate cancer-associated fibroblasts is a poor prognostic indicator. Here we report outcomes of direct and indirect co-cultures of immortalised AR-positive (PShTert-AR) or AR-negative (PShTert) myofibroblasts with prostate cancer cells. In the initial co-cultures the AR-negative PC3 cell line was used so AR expression and signalling were restricted to the myofibroblasts. In both direct and indirect co-culture with PShTert-AR myofibroblasts, paracrine signalling to the PC3 cells slowed proliferation and induced apoptosis. In contrast, PC3 cells proliferated with PShTert myofibroblasts irrespective of the co-culture method. In direct co-culture PC3 cells induced apoptosis in and destroyed PShTerts by direct signalling. Similar results were seen in direct co-cultures with AR-negative DU145 and AR-positive LNCaP and C4-2B prostate cancer cell lines. The AR ligand 5α-dihydrotestosterone (DHT) inhibited the proliferation of the PShTert-AR myofibroblasts, thereby reducing the extent of their inhibitory effect on cancer cell growth. These results suggest loss of stromal AR would favour prostate cancer cell growth in vivo , providing an explanation for the clinical observation that reduced stromal AR is associated with a poorer outcome.
Koukourakis, Michael I; Kalamida, Dimitra; Mitrakas, Achilleas G; Liousia, Maria; Pouliliou, Stamatia; Sivridis, Efthimios; Giatromanolaki, Alexandra
Cooperation of cancer cells with stromal cells, such as cancer-associated fibroblasts (CAFs), has been revealed as a mechanism sustaining cancer cell survival and growth. In the current study, we focus on the metabolic interactions of MRC5 lung fibroblasts with lung cancer cells (A549 and H1299) using co-culture experiments and studying changes of the metabolic protein expression profile and of their growth and migration abilities. Using western blotting, confocal microscopy and RT-PCR, we observed that in co-cultures MRC5 respond by upregulating pyruvate dehydrogenase (PDH) and the monocarboxylate transporter MCT1. In contrast, cancer cells increase the expression of glucose transporters (GLUT1), LDH5, PDH kinase and the levels of phosphorylated/inactivated pPDH. H1299 cells growing in the same culture medium with fibroblasts exhibit a 'metastasis-like' phenomenon by forming nests within the fibroblast area. LDH5 and pPDH were drastically upregulated in these nests. The growth rate of both MRC5 and cancer cells increased in co-cultures. Suppression of LDHA or PDK1 in cancer cells abrogates the stimulatory signal from cancer cells to fibroblasts. Incubation of MRC5 fibroblasts with lactate resulted in an increase of LDHB and of PDH expression. Silencing of PDH gene in fibroblasts, or silencing of PDK1 or LDHA gene in tumor cells, impedes cancer cell's migration ability. Overall, a metabolic cooperation between lung cancer cells and fibroblasts has been confirmed in the context of direct Warburg effect, thus the fibroblasts reinforce aerobic metabolism to support the intensified anaerobic glycolytic pathways exploited by cancer cells.
Zhao, Siyan; Rogers, Matthew J; He, Jianzhong
Trihalomethanes such as chloroform and bromoform, although well-known as a prominent class of disinfection by-products, are ubiquitously distributed in the environment due to widespread industrial usage in the past decades. Chloroform and bromoform are particularly concerning, of high concentrations detected and with long half-lives up to several hundred days in soils and groundwater. In this study, we report a Dehalobacter- and Desulfovibrio-containing co-culture that exhibits dehalogenation of chloroform (~0.61 mM) to dichloromethane and bromoform (~0.67 mM) to dibromomethane within 10-15 days. This co-culture was further found to dechlorinate 1,1,1-trichloroethane (1,1,1-TCA) (~0.65 mM) to 1,1-dichloroethane within 12 days. The Dehalobacter species present in this co-culture, designated Dehalobacter sp. THM1, was found to couple growth with dehalogenation of chloroform, bromoform, and 1,1,1-TCA. Strain THM1 harbors a newly identified reductive dehalogenase (RDase), ThmA, which catalyzes chloroform, bromoform, and 1,1,1-TCA dehalogenation. Additionally, based on the sequences of thmA and other identified chloroform RDase genes, ctrA, cfrA, and tmrA, a pair of chloroform RDase gene-specific primers were designed and successfully applied to investigate the chloroform dechlorinating potential of microbial communities. The comparative analysis of chloroform RDases with tetrachloroethene RDases suggests a possible approach in predicting the substrate specificity of uncharacterized RDases in the future.
Kalpakci, Kerem N; Kim, Eric J; Athanasiou, Kyriacos A
Treatments for patients suffering from severe temporomandibular joint (TMJ) dysfunction are limited, motivating the development of strategies for tissue regeneration. In this study, co-cultures of fibrochondrocytes (FCs) and articular chondrocytes (ACs) were seeded in agarose wells, and supplemented with growth factors, to engineer tissue with biomechanical properties and extracellular matrix composition similar to native TMJ fibrocartilage. In the first phase, growth factors were applied alone and in combination, in the presence or absence of serum, while in the second phase, the best overall treatment was applied at intermittent dosing. Continuous treatment of AC/FC co-cultures with TGF-β1 in serum-free medium resulted in constructs with glycosaminoglycan/wet weight ratios (12.2%), instantaneous compressive moduli (790 kPa), relaxed compressive moduli (120 kPa) and Young's moduli (1.87 MPa) that overlap with native TMJ disc values. Among co-culture groups, TGF-β1 treatment increased collagen deposition ∼20%, compressive stiffness ∼130% and Young's modulus ∼170% relative to controls without growth factor. Serum supplementation, though generally detrimental to functional properties, was identified as a powerful mediator of FC construct morphology. Finally, both intermittent and continuous TGF-β1 treatment showed positive effects, though continuous treatment resulted in greater enhancement of construct functional properties. This work proposes a strategy for regeneration of TMJ fibrocartilage and its future application will be realized through translation of these findings to clinically viable cell sources. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Liu, Yuchun; Chan, Jerry K Y; Teoh, Swee-Hin
Poor angiogenesis within tissue-engineered grafts has been identified as a main challenge limiting the clinical introduction of bone tissue-engineering (BTE) approaches for the repair of large bone defects. Thick BTE grafts often exhibit poor cellular viability particularly at the core, leading to graft failure and lack of integration with host tissues. Various BTE approaches have been explored for improving vascularisation in tissue-engineered constructs and are briefly discussed in this review. Recent investigations relating to co-culture systems of endothelial and osteoblast-like cells have shown evidence of BTE efficacy in increasing vascularization in thick constructs. This review provides an overview of key concepts related to bone formation and then focuses on the current state of engineered vascularized co-culture systems using bone repair as a model. It will also address key questions regarding the generation of clinically relevant vascularized bone constructs as well as potential directions and considerations for research with the objective of pursuing engineered co-culture systems in other disciplines of vascularized regenerative medicine. The final objective is to generate serious and functional long-lasting vessels for sustainable angiogenesis that will enable enhanced cellular survival within thick voluminous bone grafts, thereby aiding in bone formation and remodelling in the long term. However, more evidence about the quality of blood vessels formed and its associated functional improvement in bone formation as well as a mechanistic understanding of their interactions are necessary for designing better therapeutic strategies for translation to clinical settings. Copyright © 2012 John Wiley & Sons, Ltd.
Restu Syamsul Hadi
Full Text Available Background Transplanted allogeneic dermal fibroblasts retain stem cell subpopulations, and are easily isolated, expanded and stored using standard techniques. Their potential for regenerative therapy of chronic wounds should be evaluated. The aim of this study was to determine allogeneic fibroblast viability in the presence of peripheral blood mononuclear cells (PBMC. Methods In this experimental study, fibroblasts were isolated from foreskin explants, expanded in the presence of serum, and stored using slow-freezing. We used one intervention group of allogeneic fibroblasts co-cultured with PBMC and 2 control groups of separate fibroblast and PBMC cultures.Fibroblasts were characterized by their collagen secretion and octamer-binding transcription factor 4 (OCT4 expression. Viability was evaluated using water soluble tetrazolium-1 (WST-1 proliferation assay. Absorbances were measured at 450 nm. Data analysis was performed by student’s paired t-test. Results Dermal fibroblasts were shown to secrete collagen, express OCT4, be recoverable after cryopreservation, and become attached to the culture dish in a co-culture with PBMC. Co-cultured and control fibroblasts had no significantly different cell viabilities (p>0.05. Calculated viable cell numbers increased 1.8 and 5.1-fold, respectively, at days 2 and 4 in vitro. Both groups showed comparable doubling times at days 2 and 4 in vitro. PBMC did not interfere with allogeneic fibroblast viability and proliferative capacity Conclusions Allogeneic fibroblasts remain viable and proliferate in the presence of host PBMC. Future research should evaluate allogeneic human dermal fibroblast competency in clinical settings. Dermal fibroblasts are a potential source for cell therapy in chronic wound management.
Seemann, Ralf; Brinkmann, Martin; Pfohl, Thomas; Herminghaus, Stephan
Droplet based microfluidics is a rapidly growing interdisciplinary field of research combining soft matter physics, biochemistry and microsystems engineering. Its applications range from fast analytical systems or the synthesis of advanced materials to protein crystallization and biological assays for living cells. Precise control of droplet volumes and reliable manipulation of individual droplets such as coalescence, mixing of their contents, and sorting in combination with fast analysis tools allow us to perform chemical reactions inside the droplets under defined conditions. In this paper, we will review available drop generation and manipulation techniques. The main focus of this review is not to be comprehensive and explain all techniques in great detail but to identify and shed light on similarities and underlying physical principles. Since geometry and wetting properties of the microfluidic channels are crucial factors for droplet generation, we also briefly describe typical device fabrication methods in droplet based microfluidics. Examples of applications and reaction schemes which rely on the discussed manipulation techniques are also presented, such as the fabrication of special materials and biophysical experiments.
Warrick, Jay; Casavant, Ben; Frisk, Megan; Beebe, David
Cell concentration via centrifugation is a ubiquitous step in many cell culture procedures. At the macroscale, centrifugation suffers from a number of limitations particularly when dealing with small numbers of cells (e.g., less than 50,000). On the other hand, typical microscale methods for cell concentration can affect cell physiology and bias readouts of cell behavior and function. In this paper, we present a microfluidic concentrator device that utilizes the effects of gravity to allow cells to gently settle out of a suspension into a collection region without the use of specific adhesion ligands. Dimensional analysis was performed to compare different device designs and was verified with flow modeling to optimize operational parameters. We are able to concentrate low-density cell suspensions in a microfluidic chamber, achieving a cell loss of only 1.1 ± 0.6% (SD, n=7) with no observed loss during a subsequent cell staining protocol which incorporates ~36 complete device volume replacements. This method provides a much needed interface between rare cell samples and microfluidic culture assays. PMID:20843010
Walsh, Edmond J; Feuerborn, Alexander; Wheeler, James H R; Tan, Ann Na; Durham, William M; Foster, Kevin R; Cook, Peter R
Microfluidics has great potential, but the complexity of fabricating and operating devices has limited its use. Here we describe a method - Freestyle Fluidics - that overcomes many key limitations. In this method, liquids are confined by fluid (not solid) walls. Aqueous circuits with any 2D shape are printed in seconds on plastic or glass Petri dishes; then, interfacial forces pin liquids to substrates, and overlaying an immiscible liquid prevents evaporation. Confining fluid walls are pliant and resilient; they self-heal when liquids are pipetted through them. We drive flow through a wide range of circuits passively by manipulating surface tension and hydrostatic pressure, and actively using external pumps. Finally, we validate the technology with two challenging applications - triggering an inflammatory response in human cells and chemotaxis in bacterial biofilms. This approach provides a powerful and versatile alternative to traditional microfluidics.The complexity of fabricating and operating microfluidic devices limits their use. Walsh et al. describe a method in which circuits are printed as quickly and simply as writing with a pen, and liquids in them are confined by fluid instead of solid walls.
Roelofs, Susan Helena
The main aim of the work described in this thesis is to implement the desalination technique capacitive deionization (CDI) on a microfluidic chip to improve the reproducibility in the analysis of biological samples for drug development. Secondly, microfluidic CDI allows for the in situ study of ion
Georgantzopoulou, Anastasia; Serchi, Tommaso; Cambier, Sébastien; Leclercq, Céline C; Renaut, Jenny; Shao, Jia; Kruszewski, Marcin; Lentzen, Esther; Grysan, Patrick; Eswara, Santhana; Audinot, Jean-Nicolas; Contal, Servane; Ziebel, Johanna; Guignard, Cédric; Hoffmann, Lucien; Murk, AlberTinka J; Gutleb, Arno C
The increased incorporation of silver nanoparticles (Ag NPs) into consumer products makes the characterization of potential risk for humans and other organisms essential. The oral route is an important uptake route for NPs, therefore the study of the gastrointestinal tract in respect to NP uptake and toxicity is very timely. The aim of the present study was to evaluate the effects of Ag NPs and ions on a Caco-2/TC7:HT29-MTX intestinal co-culture model with mucus secretion, which constitutes an important protective barrier to exogenous agents in vivo and may strongly influence particle uptake. The presence of the mucus layer was confirmed with staining techniques (alcian blue and toluidine blue). Mono and co-cultures of Caco-2/TC7 and HT29-MTX cells were exposed to Ag NPs (Ag 20 and 200 nm) and AgNO3 and viability (alamar blue), ROS induction (DCFH-DA assay) and IL-8 release (ELISA) were measured. The particle agglomeration in the media was evaluated with DLS and the ion release with ultrafiltration and ICP-MS. The effects of the Ag NPs and AgNO3 on cells in co-culture were studied at a proteome level with two-dimensional difference in gel electrophoresis (2D-DIGE) followed by Matrix Assisted Laser Desorption Ionization - Time Of Flight/ Time Of Flight (MALDI-TOF/TOF) mass spectrometry (MS). Intracellular localization was assessed with NanoSIMS and TEM. The presence of mucus layer led to protection against ROS and decrease in IL-8 release. Both Ag 20 and 200 nm NPs were taken up by the cells and Ag NPs 20 nm were mainly localized in organelles with high sulfur content. A dose- and size-dependent increase in IL-8 release was observed with a lack of cytotoxicity and oxidative stress. Sixty one differentially abundant proteins were identified involved in cytoskeleton arrangement and cell cycle, oxidative stress, apoptosis, metabolism/detoxification and stress. The presence of mucus layer had an impact on modulating the induced toxicity of NPs. NP-specific effects were
Anwar, Mohammad Raffaqat; Andreasen, Christian Maaløv; Lippert, Solvej Kølvraa
differentiation, we co-cultured cells from a human neural forebrain-derived stem cell line (hNS1) with rat striatal brain slices. In brief, coronal slices of neonatal rat striatum were cultured on semiporous membrane inserts placed in six-well trays overlying monolayers of hNS1 cells. After 12 days of co......Properly committed neural stem cells constitute a promising source of cells for transplantation in Parkinson's disease, but a protocol for controlled dopaminergic differentiation is not yet available. To establish a setting for identification of secreted neural compounds promoting dopaminergic...
Takanari, Hiroki; Miwa, Keiko; Fu, XianMing; Nakai, Junichi; Ito, Akira; Ino, Kousuke; Honda, Hiroyuki; Tonomura, Wataru; Konishi, Satoshi; Opthof, Tobias; van der Heyden, Marcel Ag; Kodama, Itsuo; Lee, Jong-Kook
Skeletal myoblast (SkMB) transplantation has been conducted as a therapeutic strategy for severe heart failure. However, arrhythmogenicity following transplantation remains unsolved. We developed an in vitro model of myoblast transplantation with "patterned" or "randomly-mixed" co-culture of SkMBs and cardiomyocytes enabling subsequent electrophysiological, and arrhythmogenic evaluation. SkMBs were magnetically labeled with magnetite nanoparticles and co-cultured with neonatal rat ventricular myocytes (NRVMs) on multi-electrode arrays. SkMBs were patterned by a magnet beneath the arrays. Excitation synchronicity was evaluated by Ca(2+) imaging using a gene-encoded Ca(2+) indicator, G-CaMP2. In the monoculture of NRVMs (control), conduction was well-organized. In the randomly-mixed co-culture of NRVMs and SkMBs (random group), there was inhomogeneous conduction from multiple origins. In the "patterned" co-culture where an en bloc SKMB-layer was inserted into the NRVM-layer, excitation homogenously propagated although conduction was distorted by the SkMB-area. The 4-mm distance conduction time (CT) in the random group was significantly longer (197 ± 126 ms) than in control (17 ± 3 ms). In the patterned group, CT through NRVM-area did not change (25 ± 3 ms), although CT through the SkMB-area was significantly longer (132 ± 77 ms). The intervals between spontaneous excitation varied beat-to-beat in the random group, while regular beating was recorded in the control and patterned groups. Synchronized Ca(2+) transients of NRVMs were observed in the patterned group, whereas those in the random group were asynchronous. Patterned alignment of SkMBs is feasible with magnetic nanoparticles. Using the novel in vitro model mimicking cell transplantation, it may become possible to predict arrhythmogenicity due to heterogenous cell transplantation. J. Cell. Physiol. 231: 2249-2256, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Full Text Available Steamed rice inoculated with Aspergillus oryzae, called Koji, is an essential ingredient for making amazake or brewing sake. However, A. oryzae usually offers low enzyme yield, especially in case of glucoamylase. Co-culture of Aspergillus and Rhizopus strains in Koji increased glucoamylase and α-amylase activities. The ratio of initial spore counts of A. oryzae and R. oryzae influenced the activity of amylolytic enzymes. When this ratio was 1:1, α-amylase showed maximum activity (573 U/g-substrate, 95 h, and when this ratio was 200:1, glucoamylase showed maximum activity (180 U/g-substrate, 95 h.
Takefuji Haruka; Ninomiya Junko; Morita Hiroshi
Steamed rice inoculated with Aspergillus oryzae, called Koji, is an essential ingredient for making amazake or brewing sake. However, A. oryzae usually offers low enzyme yield, especially in case of glucoamylase. Co-culture of Aspergillus and Rhizopus strains in Koji increased glucoamylase and α-amylase activities. The ratio of initial spore counts of A. oryzae and R. oryzae influenced the activity of amylolytic enzymes. When this ratio was 1:1, α-amylase showed maximum activity (573 U/g-subs...
Scott C. McCormick
Full Text Available Many unique chemical compounds and nanomaterials are being developed, and each one requires a considerable range of in vitro and/or in vivo toxicity screening in order to evaluate their safety. The current methodology of in vitro toxicological screening on cells is based on well-plate assays that require time-consuming manual handling or expensive automation to gather enough meaningful toxicology data. Cost reduction; access to faster, more comprehensive toxicity data; and a robust platform capable of quantitative testing, will be essential in evaluating the safety of new chemicals and nanomaterials, and, at the same time, in securing the confidence of regulators and end-users. Microfluidic chips offer an alternative platform for toxicity screening that has the potential to transform both the rates and efficiency of nanomaterial testing, as reviewed here. The inherent advantages of microfluidic technologies offer high-throughput screening with small volumes of analytes, parallel analyses, and low-cost fabrication.
Takeuchi, Akimasa; Tani, Hiromasa; Mori, Masahide; Moriguchi, Hiroyuki; Kotani, Kiyoshi; Lee, Jong-Kook; Noshiro, Makoto; Jimbo, Yasuhiko
The sympathetic nervous system is one of the principal sources for regulating cardiovascular functions. Little is known, however, about the network-level interactions between sympathetic neurons and cardiomyocytes. In this study, a semi-separated co-culture system of superior cervical ganglion (SCG) neurons and ventricular myocytes (VMs) was developed by using a polydimethylsyloxane (PDMS) chamber placed on a microelectrode-array (MEA) substrate. Neurites of SCG neurons passed through a conduit of the chamber and reached VMs. Evoked activities of SCG neurons were observed from several electrodes immediately after applying constant-voltage stimulation (1 V, 1 ms, biphasic square pulses) to SCG neurons by using 32 electrodes. Furthermore, this stimulation was applied to SCG neurons at the frequency of 1, 5 and 10 Hz. After applying these three kinds of stimulations, mean minute contraction rate of VMs increased with an increase in the frequency of stimulation. These results suggest that changes in contraction rate of VMs after applying electrical stimulations to SCG neurons depend on frequencies of these stimulations and that the heart-regulating mechanisms as well as that in the body were formed in this co-culture system.
Naseri, M.; Rahimi, M.; Faramarz, M.
Haploid production focuses on low plant regeneration in some wheat genotypes. Haploid application gamma ray as an electromagnetic ray has ionizing properties which can produce ions when passing through biological matter. It can produce genetic variation therefore, is applied in crop and ornamental improvement to enhance agronomic traits. The most important changes caused by gamma radiation is in DNA structure existing in the nucleus of cell. The desirable agronomic changes then will be passed on through generations. Another property of gamma ray can be it's stimulating effect which is the aim in this investigation. Microspore-overy co-culture of wheat along with application of low doses of gamma radiation 2,3 and 4 Gy as absorbing doses were implemented with the aim to evaluate wheat haploid production. Modified Morashig and Skoog medium was used as induction medium and 190-2 medium for regeneration. Two winter and two spring wheat cultivars were used as genetic material. Low doses of gamma radiation simulated microspore cell division and produced more calli relative to non-irradiated microspores only in winter type wheats. In microspore overy co-culture, filtered microspores were centrifuged and then plated in Petri dishes containing MMS+500 mg/I glutamine with 25 overies
A microfluidic component (100) for building a microfluidic system is provided. The microfluidic component (100) can be mounted on a microf luidic breadboard (202) in a manner that allows it to be connected to other microfluidic components (204, 206) without the requirement of additional devices....... The microfluidic component (100) comprises at least one flexible tube piece (102) for transporting a fluid. The microfluidic component (100) also comprises means for applying and maintaining pressure (104) between the flexible tube piece (102) and a tube piece (208, 210) housed in another microfluidic component...
Tarallo, Sonia; Beltramo, Elena; Berrone, Elena; Porta, Massimo
Pericytes regulate vascular tone, perfusion pressure and endothelial cell (EC) proliferation in capillaries. Thiamine and benfotiamine counteract high glucose-induced damage in vascular cells. We standardized two human retinal pericyte (HRP)/EC co-culture models to mimic the diabetic retinal microvascular environment. We aimed at evaluating the interactions between co-cultured HRP and EC in terms of proliferation/apoptosis and the possible protective role of thiamine and benfotiamine against high glucose-induced damage. EC and HRP were co-cultured in physiological glucose and stable or intermittent high glucose, with or without thiamine/benfotiamine. No-contact model: EC were plated on a porous membrane suspended into the medium and HRP on the bottom of the same well. Cell-to-cell contact model: EC and HRP were plated on the opposite sides of the same membrane. Proliferation (cell counts and DNA synthesis), apoptosis and tubule formation in Matrigel were assessed. In the no-contact model, stable high glucose reduced proliferation of co-cultured EC/HRP and EC alone and increased co-cultured EC/HRP apoptosis. In the contact model, both stable and intermittent high glucose reduced co-cultured EC/HRP proliferation and increased apoptosis. Stable high glucose had no effects on HRP in separate cultures. Both EC and HRP proliferated better when co-cultured. Thiamine and benfotiamine reversed high glucose-induced damage in all cases. HRP are sensitive to soluble factors released by EC when cultured in high glucose conditions, as suggested by conditioned media assays. In the Matrigel models, addition of thiamine and benfotiamine re-established the high glucose-damaged interactions between EC/HRP and stabilized microtubules.
Full Text Available Microfluidic devices are an emerging platform for a variety of experiments involving bacterial cell culture, and has advantages including cost and convenience. One inevitable step during bacterial cell culture is the measurement of cell concentration in the channel. The optical density measurement technique is generally used for bacterial growth estimation, but it is not applicable to microfluidic devices due to the small sample volumes in microfluidics. Alternately, cell counting or colony-forming unit methods may be applied, but these do not work in situ; nor do these methods show measurement results immediately. To this end, we present a new vision-based method to estimate the growth level of the bacteria in microfluidic channels. We use Fast Fourier transform (FFT to detect the frequency level change of the microscopic image, focusing on the fact that the microscopic image becomes rough as the number of cells in the field of view increases, adding high frequencies to the spectrum of the image. Two types of microfluidic devices are used to culture bacteria in liquid and agar gel medium, and time-lapsed images are captured. The images obtained are analyzed using FFT, resulting in an increase in high-frequency noise proportional to the time passed. Furthermore, we apply the developed method in the microfluidic antibiotics susceptibility test by recognizing the regional concentration change of the bacteria that are cultured in the antibiotics gradient. Finally, a deep learning-based data regression is performed on the data obtained by the proposed vision-based method for robust reporting of data.
Kim, Kyukwang; Kim, Seunggyu; Jeon, Jessie S
Microfluidic devices are an emerging platform for a variety of experiments involving bacterial cell culture, and has advantages including cost and convenience. One inevitable step during bacterial cell culture is the measurement of cell concentration in the channel. The optical density measurement technique is generally used for bacterial growth estimation, but it is not applicable to microfluidic devices due to the small sample volumes in microfluidics. Alternately, cell counting or colony-forming unit methods may be applied, but these do not work in situ; nor do these methods show measurement results immediately. To this end, we present a new vision-based method to estimate the growth level of the bacteria in microfluidic channels. We use Fast Fourier transform (FFT) to detect the frequency level change of the microscopic image, focusing on the fact that the microscopic image becomes rough as the number of cells in the field of view increases, adding high frequencies to the spectrum of the image. Two types of microfluidic devices are used to culture bacteria in liquid and agar gel medium, and time-lapsed images are captured. The images obtained are analyzed using FFT, resulting in an increase in high-frequency noise proportional to the time passed. Furthermore, we apply the developed method in the microfluidic antibiotics susceptibility test by recognizing the regional concentration change of the bacteria that are cultured in the antibiotics gradient. Finally, a deep learning-based data regression is performed on the data obtained by the proposed vision-based method for robust reporting of data.
Andreasen, Sune Zoëga; Kwasny, Dorota; Amato, Letizia
Here we present a robust, stable and low-noise experimental set-up for performing electrochemical detection on a centrifugal microfluidic platform. By using a low-noise electronic component (electrical slip-ring) it is possible to achieve continuous, on-line monitoring of electrochemical experime......Here we present a robust, stable and low-noise experimental set-up for performing electrochemical detection on a centrifugal microfluidic platform. By using a low-noise electronic component (electrical slip-ring) it is possible to achieve continuous, on-line monitoring of electrochemical...
Takayama, Shuichi (Inventor); Cabrera, Lourdes Marcella (Inventor); Heo, Yun Seok (Inventor); Smith, Gary Daniel (Inventor)
Microfluidic devices for cell culturing and methods for using the same are disclosed. One device includes a substrate and membrane. The substrate includes a reservoir in fluid communication with a passage. A bio-compatible fluid may be added to the reservoir and passage. The reservoir is configured to receive and retain at least a portion of a cell mass. The membrane acts as a barrier to evaporation of the bio-compatible fluid from the passage. A cover fluid may be added to cover the bio-compatible fluid to prevent evaporation of the bio-compatible fluid.
Microfluidic scintillation detectors are devices of recent introduction for the detection of high energy particles, developed within the EP-DT group at CERN. Most of the interest for such technology comes from the use of liquid scintillators, which entails the possibility of changing the active material in the detector, leading to an increased radiation resistance. This feature, together with the high spatial resolution and low thickness deriving from the microfabrication techniques used to manufacture such devices, is desirable not only in instrumentation for high energy physics experiments but also in medical detectors such as beam monitors for hadron therapy.
Full Text Available Biochemical gradients convey information through space, time, and concentration, and are ultimately capable of spatially resolving distinct cellular phenotypes, such as differentiation, proliferation, and migration. How these gradients develop, evolve, and function during development, homeostasis, and various disease states is a subject of intense interest across a variety of disciplines. Microfluidic technologies have become essential tools for investigating gradient sensing in vitro due to their ability to precisely manipulate fluids on demand in well controlled environments at cellular length scales. This minireview will highlight their utility for studying gradient sensing along with relevant applications to biology.
Van Dam, Robert Michael [Univ. of California, Los Angeles, CA (United States)
Positron emission tomography (PET) imaging is used for fundamental studies of living biological organisms and microbial ecosystems in applications ranging from biofuel production to environmental remediation to the study, diagnosis, and treatment monitoring of human disease. Routine access to PET imaging, to monitor biochemical reactions in living organisms in real time, could accelerate a broad range of research programs of interest to DOE. Using PET requires access to short-lived radioactive-labeled compounds that specifically probe the desired living processes. The overall aims of this project were to develop a miniature liquid-handling technology platform (called “microfluidics”) that increases the availability of diverse PET probes by reducing the cost and complexity of their production. Based on preliminary experiments showing that microfluidic chips can synthesis such compounds, we aimed to advance this technology to improve its robustness, increase its flexibility for a broad range of probes, and increase its user-friendliness. Through the research activities of this project, numerous advances were made; Tools were developed to enable the visualization of radioactive materials within microfluidic chips; Fundamental advances were made in the microfluidic chip architecture and fabrication process to increase its robustness and reliability; The microfluidic chip technology was shown to produce useful quantities of an example PET probes, and methods to further increase the output were successfully pursued; A “universal” chip was developed that could produce multiple types of PET probes, enabling the possibility of “on demand” synthesis of different probes; and Operation of the chip was automated to ensure minimal radiation exposure to the operator Based on the demonstrations of promising technical feasibility and performance, the microfluidic chip technology is currently being commercialized. It is anticipated that costs of microfluidic chips can be
Thomas J Moutinho
Full Text Available Interactions between microbes are central to the dynamics of microbial communities. Understanding these interactions is essential for the characterization of communities, yet challenging to accomplish in practice. There are limited available tools for characterizing diffusion-mediated, contact-independent microbial interactions. A practical and widely implemented technique in such characterization involves the simultaneous co-culture of distinct bacterial species and subsequent analysis of relative abundance in the total population. However, distinguishing between species can be logistically challenging. In this paper, we present a low-cost, vertical membrane, co-culture plate to quantify contact-independent interactions between distinct bacterial populations in co-culture via real-time optical density measurements. These measurements can be used to facilitate the analysis of the interaction between microbes that are physically separated by a semipermeable membrane yet able to exchange diffusible molecules. We show that diffusion across the membrane occurs at a sufficient rate to enable effective interaction between physically separate cultures. Two bacterial species commonly found in the cystic fibrotic lung, Pseudomonas aeruginosa and Burkholderia cenocepacia, were co-cultured to demonstrate how this plate may be implemented to study microbial interactions. We have demonstrated that this novel co-culture device is able to reliably generate real-time measurements of optical density data that can be used to characterize interactions between microbial species.
Kaur, Pavinder; Ward, Brenda; Saha, Baisakhi; Young, Lillian; Groshen, Susan; Techy, Geza; Lu, Yani; Atkinson, Roscoe; Taylor, Clive R; Ingram, Marylou; Imam, S Ashraf
Progress in our understanding of heterotypic cellular interaction in the tumor microenvironment, which is recognized to play major roles in cancer progression, has been hampered due to unavailability of an appropriate in vitro co-culture model. The aim of this study was to generate an in vitro 3-dimensional human breast cancer model, which consists of cancer cells and fibroblasts. Breast cancer cells (UACC-893) and fibroblasts at various densities were co-cultured in a rotating suspension culture system to establish co-culture parameters. Subsequently, UACC-893, BT.20, or MDA.MB.453 were co-cultured with fibroblasts for 9 days. Co-cultures resulted in the generation of breast cancer histoid (BCH) with cancer cells showing the invasion of fibroblast spheroids, which were visualized by immunohistochemical (IHC) staining of sections (4 µm thick) of BCH. A reproducible quantitative expression of C-erbB.2 was detected in UACC-893 cancer cells in BCH sections by IHC staining and the Automated Cellular Imaging System. BCH sections also consistently exhibited qualitative expression of pancytokeratins, p53, Ki-67, or E-cadherin in cancer cells and that of vimentin or GSTPi in fibroblasts, fibronectin in the basement membrane and collagen IV in the extracellular matrix. The expression of the protein analytes and cellular architecture of BCH were markedly similar to those of breast cancer tissue.
Hyeong Min Son
Full Text Available The present study investigated the CaCO3 precipitation performance of ureolytic and non-ureolytic bacteria co-cultured as a self-healing agent for cementitious materials crack repair. Three different inoculum ratios of ureolytic Sporosarcina pasteurii and non-ureolytic Bacillus thuringiensis (10:0, 8:2, or 5:5 were used. The effect of coculturing ureolytic and non-ureolytic bacteria on microbial metabolism was investigated by measuring the rate of growth in urea-containing medium and the rate of NH4+ and CaCO3 production in urea–calcium lactate medium. The self-healing efficiency of co-cultured bacteria was examined by exposing cement mortar specimens with predefined cracks to media containing single urease-producing or co-cultured bacteria. The obtained results provide new findings, where CaCO3 precipitation is improved by co-culturing ureolytic and non-ureolytic bacteria, owing to the relatively faster growth rate of non-ureolytic bacteria. The crack filling rate correlated with the width of crack, in particular, specimens with a smaller crack width showed the faster filling effect, indicating that the crack width can be a dominant factor influencing the CaCO3 precipitation capacity of co-cultured bacteria.
Guo, Chaolin; Zhao, Liting; Wang, Feng; Lu, Jian; Ding, Zhongyang; Shi, Guiyang
Laccase is widely used in several industrial applications and co-culture is a common method for enhancing laccase production in submerged fermentation. In this study, the co-culture of four yeasts with Pleurotus eryngii var. ferulae was found to enhance laccase production. An analysis of sterilization temperatures and extraction conditions revealed that the stimulatory compound in yeasts was temperature-sensitive, and that it was fat-soluble. An LC-MS analysis revealed that the possible stimulatory compound for laccase production in the four yeast extracts was β-carotene. Moreover, the addition of 4 mg β-carotene to 150 mL of P. eryngii var. ferulae culture broth improved laccase production by 2.2-fold compared with the control (i.e., a monoculture), and was similar to laccase production in co-culture. In addition, the enhanced laccase production was accompanied by an increase of lac gene transcription, which was 6.2-time higher than the control on the fifth day. Therefore, it was concluded that β-carotene from the co-cultured yeasts enhanced laccase production in P. eryngii var. ferulae , and strains that produce β-carotene could be selected to enhance fungal laccase production in a co-culture. Alternatively, β-carotene or crude extracts of β-carotene could be used to induce high laccase production in large scale.
Droplet-based microfluidic devices have become a preferred versatile platform for various fields in physics, chemistry and biology. Polydimethylsiloxane soft lithography, the mainstay for fabricating microfluidic devices, usually requires the usage of expensive apparatus and a complex manufacturing procedure. Here, we report the design and fabrication of simple and inexpensive microfluidic devices based on microscope glass slides and pulled glass capillaries, for generating monodisperse multiple emulsions. The advantages of our method lie in a simple manufacturing procedure, inexpensive processing equipment and flexibility in the surface modification of the designed microfluidic devices. Different types of devices have been designed and tested and the experimental results demonstrated their robustness for preparing monodisperse single, double, triple and multi-component emulsions. © 2014 IOP Publishing Ltd.
Araci, Ismail Emre; Pop, Paul; Chakrabarty, Krishnendu
of this paper is on continuous-flow biochips, where the basic building block is a microvalve. By combining these microvalves, more complex units such as mixers, switches, multiplexers can be built, hence the name of the technology, “microfluidic Very Large-Scale Integration” (mVLSI). A roadblock......Microfluidic biochips are replacing the conventional biochemical analyzers by integrating all the necessary functions for biochemical analysis using microfluidics. Biochips are used in many application areas, such as, in vitro diagnostics, drug discovery, biotech and ecology. The focus...... presents the state-of-the-art in the mVLSI platforms and emerging research challenges in the area of continuous-flow microfluidics, focusing on testing techniques and fault-tolerant design....
Full Text Available The aim of this work was to create a microfluidic platform that uses in vitro fertilization (IVF and avoids unnecessary damage to oocytes due to the dielectrophoretic force manipulation of the sperms and oocytes that occurs in a traditional IVF operation. The device from this research can serve also to decrease medium volumes, as well as the cost of cell culture under evaporation, and to prevent unnecessary risk in intracytoplasmic sperm injection (ICSI. To decrease the impact and destruction of the oocyte and the sperm, we adopted a positive dielectrophoretic force to manipulate both the sperms and the oocyte. The mouse oocytes were trapped with a positive dielectrophoretic (p-DEP force by using Indium Tin Oxide (ITO-glass electrodes; the ITO-glass electrode chip was fabricated by wet etching the ITO-glass. The polydimethylsiloxane (PDMS flow-focusing microfluidic device was used to generate microdroplets of micrometer size to contain the zygotes. The volume of the microdroplets was controlled by adjusting the flow rates of both inlets for oil and the DEP buffer. As a result, the rate of fertilization was increased by about 5% beyond that of the DEP treatment in traditional IVF, and more than 20% developed to the blastocyst stage with a low sperm-oocyte ratio.
Kapranov, N M; Davydova, Yu O; Gal'tseva, I V; Petinati, N A; Bakshinskaitė, M V; Drize, N I; Kuz'mina, L A; Parovichnikova, E N; Savchenko, V G
We studied the effect of autologous and allogeneic lymphocytes on multipotent mesenchymal stromal cells in co-culture. It is shown that changes in multipotent mesenchymal stromal cells and in lymphocytes did not depend on the source of lymphocytes. Contact with lymphocytes triggers expression of HLA-DR molecules on multipotent mesenchymal stromal cells and these cells lose their immune privilege. In multipotent mesenchymal stromal cells, the relative level of expression of factors involved in immunomodulation (IDO1, PTGES, and IL-6) and expression of adhesion molecule ICAM1 increased, while expression of genes involved in the differentiation of multipotent mesenchymal stromal cells remained unchanged. Priming of multipotent mesenchymal stromal cells with IFN did not affect these changes. In turn, lymphocytes underwent activation, expression of HLA-DR increased, subpopulation composition of lymphocytes changed towards the increase in the content of naïve T cells. These findings are important for cell therapy.
Adler, M.; Chang, F.C.T.; Foster, R.E.; Glenn, J.F.; Mark, G.; Maxwell, D.
The authors investigate the effects of the irreversible organophosphorous cholinesterase inhibitor, DFP, on clonal G8-1 myotubes co-cultured with ACh- secreting NG108-15 neuroblastoma x glioma hybrid cells. The enzyme activity is shown, plotted as a function of time in culture. The enzyme activity remained low over four days. At the end of this time, the cultures were nearly confluent with myoblasts but contained less than 2% multinucleated myotubes. The AChE activity increased gradually after horse serum was added to the growth medium to promote myotube formation, reaching a maximum of 1.1 nmole. C 14 ACh/min/mg protein on the 15th day
Microfluidic fuel cells and batteries represent a special type of electrochemical power generators that can be miniaturized and integrated in a microfluidic chip. Summarizing the initial ten years of research and development in this emerging field, this SpringerBrief is the first book dedicated to microfluidic fuel cell and battery technology for electrochemical energy conversion and storage. Written at a critical juncture, where strategically applied research is urgently required to seize impending technology opportunities for commercial, analytical, and educational utility, the intention is
Chan, Eugene Y.; Bae, Candice
A highly efficient means of microfluidic mixing has been created for use with the rHEALTH sensor an elliptical mixer and passive curvilinear mixing patterns. The rHEALTH sensor provides rapid, handheld, complete blood count, cell differential counts, electrolyte measurements, and other lab tests based on a reusable, flow-based microfluidic platform. These geometries allow for cleaning in a reusable manner, and also allow for complete mixing of fluid streams. The microfluidic mixing is performed by flowing two streams of fluid into an elliptical or curvilinear design that allows the combination of the flows into one channel. The mixing is accomplished by either chaotic advection around micro - fluidic loops. All components of the microfluidic chip are flow-through, meaning that cleaning solution can be introduced into the chip to flush out cells, plasma proteins, and dye. Tests were performed on multiple chip geometries to show that cleaning is efficient in any flowthrough design. The conclusion from these experiments is that the chip can indeed be flushed out with microliter volumes of solution and biological samples are cleaned readily from the chip with minimal effort. The technology can be applied in real-time health monitoring at patient s bedside or in a doctor s office, and real-time clinical intervention in acute situations. It also can be used for daily measurement of hematocrit for patients on anticoagulant drugs, or to detect acute myocardial damage outside a hospital.
Li, Baichen; Li, Lin; Guan, Allan; Dong, Quan; Ruan, Kangcheng; Hu, Ronggui; Li, Zhenyu
Microfluidics and lab-on-a-chip technologies have made it possible to manipulate small volume liquids with unprecedented resolution, automation and integration. However, most current microfluidic systems still rely on bulky off-chip infrastructures such as compressed pressure sources, syringe pumps and computers to achieve complex liquid manipulation functions. Here, we present a handheld automated microfluidic liquid handling system controlled by a smartphone, which is enabled by combining elastomeric on-chip valves and a compact pneumatic system. As a demonstration, we show that the system can automatically perform all the liquid handling steps of a bead-based HIV1 p24 sandwich immunoassay on a multi-layer PDMS chip without any human intervention. The footprint of the system is 6 × 10.5 × 16.5 cm, and the total weight is 829 g including battery. Powered by a 12.8 V 1500 mAh Li battery, the system consumed 2.2 W on average during the immunoassay and lasted for 8.7 h. This handheld microfluidic liquid handling platform is generally applicable to many biochemical and cell-based assays requiring complex liquid manipulation and sample preparation steps such as FISH, PCR, flow cytometry and nucleic acid sequencing. In particular, the integration of this technology with read-out biosensors may help enable the realization of the long-sought Tricorder-like handheld in vitro diagnostic (IVD) systems.
De Vitis, Stefania
The aim of this work is the development of a microfluidic immunosensor for the immobilization of cancer cells and their separation from healthy cells by using "in situ" microfluidic biofunctionalization protocols. These protocols allow to link antibodies on microfluidic device surfaces and can be used to study the interaction between cell membrane and biomolecules. Moreover they allow to perform analysis with high processing speed, small quantity of reagents and samples, short reaction times and low production costs. In this work the developed protocols were used in microfluidic devices for the isolation of cancer cells in heterogeneous blood samples by exploiting the binding of specific antibody to an adhesion protein (EpCAM), overexpressed on the tumor cell membranes. The presented biofunctionalization protocols can be performed right before running the experiment: this allows to have a flexible platform where biomolecules of interest can be linked on the device surface according to the user\\'s needs. © 2014 Elsevier B.V. All rights reserved.
Muoth, Carina; Wichser, Adrian; Monopoli, Marco; Correia, Manuel; Ehrlich, Nicky; Loeschner, Katrin; Gallud, Audrey; Kucki, Melanie; Diener, Liliane; Manser, Pius; Jochum, Wolfram; Wick, Peter; Buerki-Thurnherr, Tina
There is increasing evidence that certain nanoparticles (NPs) can overcome the placental barrier, raising concerns on potential adverse effects on the growing fetus. But even in the absence of placental transfer, NPs may pose a risk to proper fetal development if they interfere with the viability and functionality of the placental tissue. The effects of NPs on the human placenta are not well studied or understood, and predictive in vitro placenta models to achieve mechanistic insights on NP-placenta interactions are essentially lacking. Using the scaffold-free hanging drop technology, we developed a well-organized and highly reproducible 3D co-culture microtissue (MT) model consisting of a core of placental fibroblasts surrounded by a trophoblast cell layer, which resembles the structure of the in vivo placental tissue. We could show that secretion levels of human chorionic gonadotropin (hCG) were significantly higher in 3D than in 2D cell cultures, which indicates an enhanced differentiation of trophoblasts grown on 3D MTs. NP toxicity assessment revealed that cadmium telluride (CdTe) and copper oxide (CuO) NPs but not titanium dioxide (TiO 2 ) NPs decreased MT viability and reduced the release of hCG. NP acute toxicity was significantly reduced in 3D co-culture MTs compared to 2D monocultures. Taken together, 3D placental MTs provide a new and promising model for the fast generation of tissue-relevant acute NP toxicity data, which are indispensable for the safe development of NPs for industrial, commercial and medical applications.
Sygnecka, Katja; Heider, Andreas; Scherf, Nico; Alt, Rüdiger; Franke, Heike; Heine, Claudia
Mesenchymal stem cells (MSCs) have been identified as promising candidates for neuroregenerative cell therapies. However, the impact of different isolation procedures on the functional and regenerative characteristics of MSC populations has not been studied thoroughly. To quantify these differences, we directly compared classically isolated bulk bone marrow-derived MSCs (bulk BM-MSCs) to the subpopulation Sca-1(+)Lin(-)CD45(-)-derived MSCs(-) (SL45-MSCs), isolated by fluorescence-activated cell sorting from bulk BM-cell suspensions. Both populations were analyzed with respect to functional readouts, that are, frequency of fibroblast colony forming units (CFU-f), general morphology, and expression of stem cell markers. The SL45-MSC population is characterized by greater morphological homogeneity, higher CFU-f frequency, and significantly increased nestin expression compared with bulk BM-MSCs. We further quantified the potential of both cell populations to enhance neuronal fiber growth, using an ex vivo model of organotypic brain slice co-cultures of the mesocortical dopaminergic projection system. The MSC populations were cultivated underneath the slice co-cultures without direct contact using a transwell system. After cultivation, the fiber density in the border region between the two brain slices was quantified. While both populations significantly enhanced fiber outgrowth as compared with controls, purified SL45-MSCs stimulated fiber growth to a larger degree. Subsequently, we analyzed the expression of different growth factors in both cell populations. The results show a significantly higher expression of brain-derived neurotrophic factor (BDNF) and basic fibroblast growth factor in the SL45-MSCs population. Altogether, we conclude that MSC preparations enriched for primary MSCs promote neuronal regeneration and axonal regrowth, more effectively than bulk BM-MSCs, an effect that may be mediated by a higher BDNF secretion.
Takasaki, K; Fujise, O; Miura, M; Hamachi, T; Maeda, K
Biofilm formation occurs through the events of cooperative growth and competitive survival among multiple species. Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans are important periodontal pathogens. The aim of this study was to demonstrate competitive or cooperative interactions between these two species in co-cultured biofilm. P. gingivalis strains and gingipain mutants were cultured with or without A. actinomycetemcomitans. Biofilms formed on glass surfaces were analyzed by crystal violet staining and colony counting. Preformed A. actinomycetemcomitans biofilms were treated with P. gingivalis culture supernatants. Growth and proteolytic activities of gingipains were also determined. Monocultured P. gingivalis strains exhibited a range of biofilm-formation abilities and proteolytic activities. The ATCC33277 strain, noted for its high biofilm-formation ability and proteolytic activity, was found to be dominant in biofilm co-cultured with A. actinomycetemcomitans. In a time-resolved assay, A. actinomycetemcomitans was primarily the dominant colonizer on a glass surface and subsequently detached in the presence of increasing numbers of ATCC33277. Detachment of preformed A. actinomycetemcomitans biofilm was observed by incubation with culture supernatants from highly proteolytic strains. These results suggest that P. gingivalis possesses a competitive advantage over A. actinomycetemcomitans. As the required biofilm-formation abilities and proteolytic activities vary among P. gingivalis strains, the diversity of the competitive advantage is likely to affect disease recurrence during periodontal maintenance. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Beliaev, Alex S.; Romine, Margaret F.; Serres, Margaret; Bernstein, Hans C.; Linggi, Bryan E.; Markillie, Lye Meng; Isern, Nancy G.; Chrisler, William B.; Kucek, Leo A.; Hill, Eric A.; Pinchuk, Grigoriy; Bryant, Donald A.; Wiley, H. S.; Fredrickson, Jim K.; Konopka, Allan
We employed deep sequencing technology to identify transcriptional adaptation of the euryhaline unicellular cyanobacterium Synechococcus sp. PCC 7002 and the marine facultative aerobe Shewanella putrefaciens W3-18-1 to growth in a co-culture and infer the effect of carbon flux distributions on photoautotroph-heterotroph interactions. The overall transcriptome response of both organisms to co-cultivation was shaped by their respective physiologies and growth constraints. Carbon limitation resulted in the expansion of metabolic capacities which was manifested through the transcriptional upregulation of transport and catabolic pathways. While growth coupling occurred via lactate oxidation or secretion of photosynthetically fixed carbon, there was evidence of specific metabolic interactions between the two organisms. On one hand, the production and excretion of specific amino acids (methionine and alanine) by the cyanobacterium correlated with the putative downregulation of the corresponding biosynthetic machinery of Shewanella W3-18-1. On the other hand, the broad and consistent decrease of mRNA levels for many Fe-regulated Synechococcus 7002 genes during co-cultivation suggested increased Fe availability as well as more facile and energy-efficient mechanisms for Fe acquisition by the cyanobacterium. Furthermore, evidence pointed at potentially novel interactions between oxygenic photoautotrophs and heterotrophs related to the oxidative stress response as transcriptional patterns suggested that Synechococcus 7002 rather than Shewanella W3-18-1 provided scavenging functions for reactive oxygen species under co-culture conditions. This study provides an initial insight into the complexity of photoautotrophic-heterotrophic interactions and brings new perspectives of their role in the robustness and stability of the association.
Peng, Chien-Chung; Liao, Wei-Hao; Chen, Ying-Hua; Wu, Chueh-Yu; Tung, Yi-Chung
Oxygen tension plays an important role in regulating various cellular functions in both normal physiology and disease states. Therefore, drug testing using conventional in vitro cell models under normoxia often possesses limited prediction capability. A traditional method of setting an oxygen tension in a liquid medium is by saturating it with a gas mixture at the desired level of oxygen, which requires bulky gas cylinders, sophisticated control, and tedious interconnections. Moreover, only a single oxygen tension can be tested at the same time. In this paper, we develop a microfluidic cell culture array platform capable of performing cell culture and drug testing under various oxygen tensions simultaneously. The device is fabricated using an elastomeric material, polydimethylsiloxane (PDMS) and the well-developed multi-layer soft lithography (MSL) technique. The prototype device has 4 × 4 wells, arranged in the same dimensions as a conventional 96-well plate, for cell culture. The oxygen tensions are controlled by spatially confined oxygen scavenging chemical reactions underneath the wells using microfluidics. The platform takes advantage of microfluidic phenomena while exhibiting the combinatorial diversities achieved by microarrays. Importantly, the platform is compatible with existing cell incubators and high-throughput instruments (liquid handling systems and plate readers) for cost-effective setup and straightforward operation. Utilizing the developed platform, we successfully perform drug testing using an anti-cancer drug, triapazamine (TPZ), on adenocarcinomic human alveolar basal epithelial cell line (A549) under three oxygen tensions ranging from 1.4% to normoxia. The developed platform is promising to provide a more meaningful in vitro cell model for various biomedical applications while maintaining desired high throughput capabilities.
Abdel Fattah, Abdel Rahman; Mishriki, Sarah; Kammann, Tobias; Sahu, Rakesh P; Geng, Fei; Puri, Ishwar K
A magnet array is employed to manipulate diamagnetic cells that are contained in paramagnetic medium to demonstrate for the first time the contactless bioprinting of three-dimensional (3D) cellular structures and co-cultures of breast cancer MCF-7 and endothelial HUVEC at prescribed locations on tissue culture treated well plates. Sequential seeding of different cell lines and the spatial displacement of the magnet array creates co-cultured cellular structures within a well without using physically intrusive well inserts. Both monotypic and co-culture experiments produce morphologically rich 3D cell structures that are otherwise absent in regular monolayer cell cultures. The magnetic contactless bioprinting of cells provides further insight into cell behaviour, invasion strategies and transformations that are useful for potential applications in drug screening, 3D cell culture formation and tissue engineering.
Gabashvili, A N; Baklaushev, V P; Grinenko, N F; Mel'nikov, P A; Cherepanov, S A; Levinsky, A B; Chehonin, V P
The tumor-suppressive effect of rat mesenchymal stem cells against low-differentiated rat C6 glioma cells during their direct and indirect co-culturing and during culturing of C6 glioma cells in the medium conditioned by mesenchymal stem cells was studied in an in vitro experiment. The most pronounced antitumor activity of mesenchymal stem cells was observed during direct co-culturing with C6 glioma cells. The number of live C6 glioma cells during indirect co-culturing and during culturing in conditioned medium was slightly higher than during direct co-culturing, but significantly differed from the control (C6 glioma cells cultured in medium conditioned by C6 glioma cells). The cytotoxic effect of medium conditioned by mesenchymal stem cells was not related to medium depletion by glioma cells during their growth. The medium conditioned by other "non-stem" cells (rat astrocytes and fibroblasts) produced no tumor-suppressive effect. Rat mesenchymal stem cells, similar to rat C6 glioma cells express connexin 43, the main astroglial gap junction protein. During co-culturing, mesenchymal stem cells and glioma C6 cells formed functionally active gap junctions. Gap junction blockade with connexon inhibitor carbenoxolone attenuated the antitumor effect observed during direct co-culturing of C6 glioma cells and mesenchymal stem cells to the level produced by conditioned medium. Cell-cell signaling mediated by gap junctions can be a mechanism of the tumor-suppressive effect of mesenchymal stem cells against C6 glioma cells. This phenomenon can be used for the development of new methods of cell therapy for high-grade malignant gliomas.
Tan, A; Fujisawa, K; Yukawa, Y; Matsunaga, Y T
We developed a robust bottom-up approach to construct open-ended, tubular co-culture constructs that simulate the human vascular morphology and microenvironment. By design, these three-dimensional artificial vessels mimic the basic architecture of an artery: a collagen-rich extracellular matrix (as the tunica externa), smooth muscle cells (SMCs) (as the tunica media), and an endothelial cell (EC) lining (as the tunica interna). A versatile needle-based fabrication technique was employed to achieve controllable arterial layouts within a PDMS-hosted collagen microchannel scaffold (330 ± 10 μm in diameter): (direct co-culture) a SMC/EC bilayer to follow the structure of an arteriole-like segment; and (encapsulated co-culture) a lateral SMC multilayer covered by an EC monolayer lining to simulate the architecture of a larger artery. Optical and fluorescence microscopy images clearly evidenced the progressive cell elongation and sprouting behavior of SMCs and ECs along the collagen gel contour and within the gel matrix under static co-culture conditions. The progressive cell growth patterns effectively led to the formation of a tubular co-culture with an internal endothelial lining expressing prominent CD31 (cluster of differentiation 31) intercellular junction markers. During a 4-day static maturation period, the artery constructs showed modest alteration in the luminal diameters (i.e. less than 10% changes from the initial measurements). This argues in favor of stable and predictable arterial architecture achieved via the proposed fabrication protocols. Both co-culture models showed a high glucose metabolic rate during the initial proliferation phase, followed by a temporary quiescent (and thus, mature) stage. These proof-of-concept models with a controllable architecture create an important foundation for advanced vessel manipulations such as the integration of relevant physiological functionality or remodeling into a vascular disease-mimicking tissue.
Linshiz, Gregory; Stawski, Nina; Goyal, Garima; Bi, Changhao; Poust, Sean; Sharma, Monica; Mutalik, Vivek; Keasling, Jay D; Hillson, Nathan J
To enable protocol standardization, sharing, and efficient implementation across laboratory automation platforms, we have further developed the PR-PR open-source high-level biology-friendly robot programming language as a cross-platform laboratory automation system. Beyond liquid-handling robotics, PR-PR now supports microfluidic and microscopy platforms, as well as protocol translation into human languages, such as English. While the same set of basic PR-PR commands and features are available for each supported platform, the underlying optimization and translation modules vary from platform to platform. Here, we describe these further developments to PR-PR, and demonstrate the experimental implementation and validation of PR-PR protocols for combinatorial modified Golden Gate DNA assembly across liquid-handling robotic, microfluidic, and manual platforms. To further test PR-PR cross-platform performance, we then implement and assess PR-PR protocols for Kunkel DNA mutagenesis and hierarchical Gibson DNA assembly for microfluidic and manual platforms.
Full Text Available Digital Microfluidics (DMF has emerged as a disruptive methodology for the control and manipulation of low volume droplets. In DMF, each droplet acts as a single reactor, which allows for extensive multiparallelization of biological and chemical reactions at a much smaller scale. DMF devices open entirely new and promising pathways for multiplex analysis and reaction occurring in a miniaturized format, thus allowing for healthcare decentralization from major laboratories to point-of-care with accurate, robust and inexpensive molecular diagnostics. Here, we shall focus on DMF platforms specifically designed for nucleic acid amplification, which is key for molecular diagnostics of several diseases and conditions, from pathogen identification to cancer mutations detection. Particular attention will be given to the device architecture, materials and nucleic acid amplification applications in validated settings.
Buttner, Ulrich; Mashraei, Yousof; Agambayev, Sumeyra; Salama, Khaled N.
Microfluidics has advanced in terms of designs and structures, however, fabrication methods are either time consuming or expensive to produce, in terms of the facilities and equipment needed. A fast and economically viable method is provided
Robinson, Tom; Dittrich, Petra S
Molecular diagnostics have helped to improve the lives of millions of patients worldwide by allowing clinicians to diagnose patients earlier as well as providing better ongoing therapies. Point-of-care (POC) testing can bring these laboratory-based techniques to the patient in a home setting or to remote settings in the developing world. However, despite substantial progress in the field, there still remain many challenges. Progress in molecular diagnostics has benefitted greatly from microfluidic technology. This chapter aims to summarise the more recent advances in microfluidic-based molecular diagnostics. Sections include an introduction to microfluidic technology, the challenges of molecular diagnostics, how microfluidic advances are working to solve these issues, some alternative design approaches, and detection within these systems.
Maisonneuve, B G C; Honegger, T; Cordeiro, J; Lecarme, O; Thiry, T; Fuard, D; Berton, K; Picard, E; Zelsmann, M; Peyrade, D
With the rise of microfluidics for the past decade, there has come an ever more pressing need for a low-cost and rapid prototyping technology, especially for research and education purposes. In this article, we report a rapid prototyping process of chromed masks for various microfluidic applications. The process takes place out of a clean room, uses a commercially available video-projector, and can be completed in less than half an hour. We quantify the ranges of fields of view and of resolutions accessible through this video-projection system and report the fabrication of critical microfluidic components (junctions, straight channels, and curved channels). To exemplify the process, three common devices are produced using this method: a droplet generation device, a gradient generation device, and a neuro-engineering oriented device. The neuro-engineering oriented device is a compartmentalized microfluidic chip, and therefore, required the production and the precise alignment of two different masks.
Dugan, Lawrence Christopher [Modesto, CA; Coleman, Matthew A [Oakland, CA
A microfluidic array card and reader system for analyzing a sample. The microfluidic array card includes a sample loading section for loading the sample onto the microfluidic array card, a multiplicity of array windows, and a transport section or sections for transporting the sample from the sample loading section to the array windows. The microfluidic array card reader includes a housing, a receiving section for receiving the microfluidic array card, a viewing section, and a light source that directs light to the array window of the microfluidic array card and to the viewing section.
Roman, Gregory T.; Culbertson, Christopher T.; Meyer, Amanda; Ramsey, J. Michael; Gonda, Steven R.
One often touted benefit of "Lab-on-a-Chip" devices is their potential for use in remote environments. The ultimate remote environment is outer space, and NASA has multiple needs in the area of analytical sensing capability in such an environment. In particular, we are interested in integrating microfluidic devices with NASA bioreactor systems. In such an integrated system, the microfluidic device will serve as a biosensor and be used for both feedback control and for detecting various bioproducts produced by cells cultured in the NASA bioreactors. As a first step in demonstrating the ability of microfluidic devices to operate under the extreme environmental conditions found in outer space, we constructed a portable, battery operated platform for testing under reduced gravity conditions on a NASA KC-135 reduced gravity research aircraft, (AKA "the vomit comet"). The test platform consisted of a microchip, two 0-8kV high voltage power supplies, a high voltage switch, a solid-state diode-pumped green laser, a channel photomultiplier, and an inertial mass measurement unit, all under the control of a laptop computer and powered by 10 D-cell alkaline batteries. Over the course of 4 KC-135 flights, 1817 fast electrophoretic separations of 4 amino acids and/or proteins were performed in a variety of gravitational environments including zero-G, Martian-G, lunar-G, and 2-G. Results from these experiments will be presented and discussed.
Giovangrandi, Laurent (Inventor); Ricco, Antonio J. (Inventor); Kovacs, Gregory (Inventor)
Techniques for enhanced microfluidic impedance spectroscopy include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. Flow in the channel is laminar. A dielectric constant of a fluid constituting either sheath flow is much less than a dielectric constant of the core fluid. Electrical impedance is measured in the channel between at least a first pair of electrodes. In some embodiments, enhanced optical measurements include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. An optical index of refraction of a fluid constituting either sheath flow is much less than an optical index of refraction of the core fluid. An optical property is measured in the channel.
Ehrlich, Daniel J; McKenna, Brian K; Evans, James G; Belkina, Anna C; Denis, Gerald V; Sherr, David H; Cheung, Man Ching
By adding an additional degree of freedom from multichannel flow, the parallel microfluidic cytometer (PMC) combines some of the best features of fluorescence-activated flow cytometry (FCM) and microscope-based high-content screening (HCS). The PMC (i) lends itself to fast processing of large numbers of samples, (ii) adds a 1D imaging capability for intracellular localization assays (HCS), (iii) has a high rare-cell sensitivity, and (iv) has an unusual capability for time-synchronized sampling. An inability to practically handle large sample numbers has restricted applications of conventional flow cytometers and microscopes in combinatorial cell assays, network biology, and drug discovery. The PMC promises to relieve a bottleneck in these previously constrained applications. The PMC may also be a powerful tool for finding rare primary cells in the clinic. The multichannel architecture of current PMC prototypes allows 384 unique samples for a cell-based screen to be read out in ∼6-10 min, about 30 times the speed of most current FCM systems. In 1D intracellular imaging, the PMC can obtain protein localization using HCS marker strategies at many times for the sample throughput of charge-coupled device (CCD)-based microscopes or CCD-based single-channel flow cytometers. The PMC also permits the signal integration time to be varied over a larger range than is practical in conventional flow cytometers. The signal-to-noise advantages are useful, for example, in counting rare positive cells in the most difficult early stages of genome-wide screening. We review the status of parallel microfluidic cytometry and discuss some of the directions the new technology may take. Copyright © 2011 Elsevier Inc. All rights reserved.
Perozziello, Gerardo; Candeloro, Patrizio; Gentile, Francesco T.; Nicastri, Annalisa; Perri, Angela Mena; Coluccio, Maria Laura; Adamo, A.; Pardeo, Francesca; Catalano, Rossella; Parrotta, Elvira; Espinosa, Horacio Dante; Cuda, Giovanni; Di Fabrizio, Enzo M.
In this paper, we describe an innovative modular microfluidic platform allowing filtering, concentration and analysis of peptides from a complex mixture. The platform is composed of a microfluidic filtering device and a superhydrophobic surface integrating surface enhanced Raman scattering (SERS) sensors. The microfluidic device was used to filter specific peptides (MW 1553.73 D) derived from the BRCA1 protein, a tumor-suppressor molecule which plays a pivotal role in the development of breast cancers, from albumin (66.5 KD), the most represented protein in human plasma. The filtering process consisted of driving the complex mixture through a porous membrane having a cut-off of 12-14 kD by hydrodynamic flow. The filtered samples coming out of the microfluidic device were subsequently deposited on a superhydrophobic surface formed by micro pillars on top of which nanograins were fabricated. The nanograins coupled to a Raman spectroscopy instrument acted as a SERS sensor and allowed analysis of the filtered sample on top of the surface once it evaporated. By using the presented platform, we demonstrate being able to sort small peptides from bigger proteins and to detect them by using a label-free technique at a resolution down to 0.1 ng μL-1. The combination of microfluidics and nanotechnology to develop the presented microfluidic platform may give rise to a new generation of biosensors capable of detecting low concentration samples from complex mixtures without the need for any sample pretreatment or labelling. The developed devices could have future applications in the field of early diagnosis of severe illnesses, e.g. early cancer detection. This journal is
Full Text Available , point-of-care (PoC) tests, which are performed at or near the site of clinical care, have gained popularity and are actively being developed. Microfluidic systems, in which small volumes of fluids can be processed, provide an ideal platform on which...
Caviglia, Claudia; Zor, Kinga; Montini, Lucia
In this work, we have developed a microfluidic cytotoxicity assay for a cell culture and detection platform, which enables both fluid handling and electrochemical/optical detection. The cytotoxic effect of anticancer drugs doxorubicin (DOX), oxaliplatin (OX) as well as OX-loaded liposomes, develo...
Kokalj, Tadej; Park, Younggeun; Vencelj, Matjaž; Jenko, Monika; Lee, Luke P
Reliable, autonomous, internally self-powered microfluidic pumps are in critical demand for rapid point-of-care (POC) devices, integrated molecular-diagnostic platforms, and drug delivery systems. Here we report on a Self-powered Imbibing Microfluidic Pump by Liquid Encapsulation (SIMPLE), which is disposable, autonomous, easy to use and fabricate, robust, and cost efficient, as a solution for self-powered microfluidic POC devices. The imbibition pump introduces the working liquid which is sucked into a porous material (paper) upon activation. The suction of the working liquid creates a reduced pressure in the analytical channel and induces the sequential sample flow into the microfluidic circuits. It requires no external power or control and can be simply activated by a fingertip press. The flow rate can be programmed by defining the shape of utilized porous material: by using three different paper shapes with circular section angles 20°, 40° and 60°, three different volume flow rates of 0.07 μL s(-1), 0.12 μL s(-1) and 0.17 μL s(-1) are demonstrated at 200 μm × 600 μm channel cross-section. We established the SIMPLE pumping of 17 μL of sample; however, the sample volume can be increased to several hundreds of μL. To demonstrate the design, fabrication, and characterization of SIMPLE, we used a simple, robust and cheap foil-laminating fabrication technique. The SIMPLE can be integrated into hydrophilic or hydrophobic materials-based microfluidic POC devices. Since it is also applicable to large-scale manufacturing processes, we anticipate that a new chapter of a cost effective, disposable, autonomous POC diagnostic chip is addressed with this technical innovation.
Millet, L J; Lucheon, J D; Standaert, R F; Retterer, S T; Doktycz, M J
Biochemical separations are the heart of diagnostic assays and purification methods for biologics. On-chip miniaturization and modularization of separation procedures will enable the development of customized, portable devices for personalized health-care diagnostics and point-of-use production of treatments. In this report, we describe the design and fabrication of miniature ion exchange, size exclusion and affinity chromatography modules for on-chip clean-up of recombinantly-produced proteins. Our results demonstrate that these common separations techniques can be implemented in microfluidic modules with performance comparable to conventional approaches. We introduce embedded 3-D microfluidic interconnects for integrating micro-scale separation modules that can be arranged and reconfigured to suit a variety of fluidic operations or biochemical processes. We demonstrate the utility of the modular approach with a platform for the enrichment of enhanced green fluorescent protein (eGFP) from Escherichia coli lysate through integrated affinity and size-exclusion chromatography modules.
Full Text Available The physical properties of cytoskeletal networks are contributors in a number of mechanical responses of cells including cellular deformation and locomotion, and are crucial for the proper action of living cells. Local chemical gradients modulate cytoskeletal functionality including the interactions of the cytoskeleton with other cellular components. Actin is a major constituent of the cytoskeleton. Introducing a microfluidic-based platform, we explored the impact of concentration gradients on the formation and structural properties of actin networks. Microfluidics-controlled flow-free steady state experimental conditions allow for the generation of chemical gradients of different profiles, such as linear or step-like. We discovered specific features of actin networks emerging in defined gradients. In particular, we analyzed the effects of spatial conditions on network properties, bending rigidities of network links, and the network elasticity.
Fang, Herbert H.P.; Zhu, Heguang; Zhang, Tong [Centre for Environmental Engineering Research, Department of Civil Engineering, University of Hong Kong, Pokfulam Road, Hong Kong (China)
Phototrophic hydrogen production from glucose by pure and co-cultures of Clostridium butyricum and Rhodobacter sphaeroides was studied in batch experiments. Results showed that in all batches hydrogen was produced after a lag phase of about 10h; pure culture of R. sphaeroides produced hydrogen at rates substantially lower than C. butyricum. In co-culture systems, R. sphaeroides even with cell populations 5.9 times higher still could not compete with C. butyricum for glucose. In co-culture systems, R. sphaeroides syntrophically interacted with C. butyricum, using the acetate and butyrate produced by the latter as substrate for hydrogen production. Hydrogen production was ceased in all batches when the pH was lowered to the level of pH 6.5, resulting from the accumulation of fatty acids. It was also demonstrated in this study that fluorescence in situ hybridization (FISH) was an effective means for the quantification of the relative abundance of individual bacteria in a co-culture system. (author)
Sousa, D.Z.; Smidt, H.; Alves, M.M.; Stams, A.J.M.
An anaerobic, mesophilic, syntrophic fatty-acid-oxidizing bacterium, designated strain OL-4T, was isolated as a co-culture with Methanobacterium formicicum DSM 1535NT from an anaerobic expanded granular sludge bed reactor used to treat an oleate-based effluent. Strain OL-4T degraded oleate, a
Contag, Christopher H.; Lie, Wen-Rong; Bammer, Marie C.; Hardy, Jonathan W.; Schmidt, Tobi L.; Maloney, William J.; King, Bonnie L.
Purpose Bone is a preferential site of breast cancer metastasis and models are needed to study this process at the level of the microenvironment. We have used bioluminescence imaging (BLI) and multiplex biomarker immunoassays to monitor dynamic breast cancer cell behaviors in co-culture with human bone tissue. Procedures Femur tissue fragments harvested from hip replacement surgeries were co-cultured with luciferase-positive MDA-MB-231-fLuc cells. BLI was performed to quantify breast cell division and track migration relative to bone tissue. Breast cell colonization of bone tissues was assessed with immunohistochemistry. Biomarkers in co-culture supernatants were profiled with MILLIPLEX® immunoassays. Results BLI demonstrated increased MDA-MB-231-fLuc proliferation (pbones, and revealed breast cell migration toward bone. Immunohistochemistry illustrated MDA-MB-231-fLuc colonization of bone, and MILLIPLEX® profiles of culture supernatants suggested breast/bone crosstalk. Conclusions Breast cell behaviors that facilitate metastasis occur reproducibly in human bone tissue co-cultures and can be monitored and quantified using BLI and multiplex immunoassays. PMID:24008275
Priya, Anchal; Mandal, Ajoy K; Ball, Andrew S; Manefield, Mike; Lal, Banwari; Sarma, Priyangshu M
In the present study a metabolically versatile co-culture with two Bacilli and one yeast strain was developed using enrichment culture techniques. The developed co-culture had affinity to degrade both aliphatic and aromatic fractions of petroleum crude oil. Degradation kinetics was established for designing the fermentation protocol of the co-culture. The developed mass culture strategy led to achieve the reduction in surface tension (26dynescm(-1) from 69 dynescm(-1)) and degradation of 67% in bench scale experiments. The total crude oil degradation of 96% was achieved in 4000l of natural seawater after 28days without adding any nutrients. The survival of the augmented co-culture was maintained (10(9)cellsml(-1)) in contaminated marine environment. The mass culture protocol devised for the bioaugmentation was a key breakthrough that was subsequently used for pilot scale studies with 100l and 4000l of natural seawater for potential application in marine oil spills. Copyright © 2015 Elsevier Ltd. All rights reserved.
Juel, Helene Bæk; Kaestel, Charlotte; Folkersen, Lasse
In this study we examined the effect of T cell-derived cytokines on retinal pigment epithelial (RPE) cells with respect to expression of complement components. We used an in vitro co-culture system in which CD3/CD28-activated human T cells were separated from the human RPE cell line (ARPE-19...
Wu, Ling; Prins, H.J.; Helder, M.; van Blitterswijk, Clemens; Karperien, Hermanus Bernardus Johannes
Earlier, we have shown that the increased cartilage production in pellet co-cultures of chondrocytes and bone marrow-derived mesenchymal stem cells (BM-MSCs) is due to a trophic role of the MSC in stimulating chondrocyte proliferation and matrix production rather than MSCs actively undergoing
Wu, L.; Prins, H.J.; Helder, M.N.; van Blitterswijk, C.A.; Karperien, M.
Earlier, we have shown that the increased cartilage production in pellet co-cultures of chondrocytes and bone marrow-derived mesenchymal stem cells (BM-MSCs) is due to a trophic role of the MSC in stimulating chondrocyte proliferation and matrix production rather than MSCs actively undergoing
Fan, Yiqiang; Li, Huawei; Foulds, Ian G.
This paper reports a new method for integrating microlenses into microfluidic devices for improved observation. Two demonstration microfluidic devices were provided which were fabricated using this new technique. The integrated microlenses were
Zhang, Menying; Gong, Xiuqing; Wen, Weijia
Microfluidics, especially droplet microfluidics, attracts more and more researchers from diverse fields, because it requires fewer materials and less time, produces less waste and has the potential of highly integrated and computer
Heeren, H. van; Atkins, T.; Blom, M.; Bullema, J.E.; Tantra, R.; Verhoeven, D.; Verplanck, N.
This paper addresses the issue of standardization in microfluidics. It contains the main points of an industry wide agreement about microfluidic port pitches and port nomenclature. It also addresses device classification and future steps.
Faria, Jorge M S; Sena, Inês; Vieira da Silva, Inês; Ribeiro, Bruno; Barbosa, Pedro; Ascensão, Lia; Bennett, Richard N; Mota, Manuel; Figueiredo, A Cristina
Co-cultures of Pinus pinaster with Bursaphelenchus xylophilus were established as a biotechnological tool to evaluate the effect of nematotoxics addition in a host/parasite culture system. The pinewood nematode (PWN), Bursaphelenchus xylophilus, the causal agent of pine wilt disease (PWD), was detected for the first time in Europe in 1999 spreading throughout the pine forests in Portugal and recently in Spain. Plant in vitro cultures may be a useful experimental system to investigate the plant/nematode relationships in loco, thus avoiding the difficulties of field assays. In this study, Pinus pinaster in vitro cultures were established and compared to in vivo 1 year-old plantlets by analyzing shoot structure and volatiles production. In vitro co-cultures were established with the PWN and the effect of the phytoparasite on in vitro shoot structure, water content and volatiles production was evaluated. In vitro shoots showed similar structure and volatiles production to in vivo maritime pine plantlets. The first macroscopic symptoms of PWD were observed about 4 weeks after in vitro co-culture establishment. Nematode population in the culture medium increased and PWNs were detected in gaps of the callus tissue and in cavities developed from the degradation of cambial cells. In terms of volatiles main components, plantlets, P. pinaster cultures, and P. pinaster with B. xylophilus co-cultures were all β- and α-pinene rich. Co-cultures may be an easy-to-handle biotechnological approach to study this pathology, envisioning the understanding of and finding ways to restrain this highly devastating nematode.
Full Text Available In mammals, circadian rhythms of various organs and tissues are synchronized by pacemaker neurons in the suprachiasmatic nucleus (SCN of the hypothalamus. Glucocorticoids released from the adrenal glands can synchronize circadian rhythms in other tissues. Many hormones show circadian rhythms in their plasma concentrations; however, whether organs outside the SCN can serve as master synchronizers to entrain circadian rhythms in target tissues is not well understood. To further delineate the function of the adrenal glands and the interactions of circadian rhythms in putative master synchronizing organs and their target tissues, here we report a simple co-culture system using a dual-color luciferase assay to monitor circadian rhythms separately in various explanted tissues and fibroblasts. In this system, circadian rhythms of organs and target cells were simultaneously tracked by the green-emitting beetle luciferase from Pyrearinus termitilluminans (ELuc and the red-emitting beetle luciferase from Phrixothrix hirtus (SLR, respectively. We obtained tissues from the adrenal glands, thyroid glands, and lungs of transgenic mice that expressed ELuc under control of the promoter from a canonical clock gene, mBmal1. The tissues were co-cultured with Rat-1 fibroblasts as representative target cells expressing SLR under control of the mBmal1 promoter. Amplitudes of the circadian rhythms of Rat-1 fibroblasts were potentiated when the fibroblasts were co-cultured with adrenal gland tissue, but not when co-cultured with thyroid gland or lung tissue. The phases of Rat-1 fibroblasts were reset by application of adrenal gland tissue, whereas the phases of adrenal gland tissue were not influenced by Rat-1 fibroblasts. Furthermore, the effect of the adrenal gland tissue on the fibroblasts was blocked by application of a glucocorticoid receptor (GR antagonist. These results demonstrate that glucocorticoids are strong circadian synchronizers for fibroblasts and that
Allon, Aliza A; Schneider, Richard A; Lotz, Jeffrey C
Our goal is to optimize stem cell-based tissue engineering strategies in the context of the intervertebral disc environment. We explored the benefits of co-culturing nucleus pulposus cells (NPC) and adult mesenchymal stem cells (MSC) using a novel spherical bilaminar pellet culture system where one cell type is enclosed in a sphere of the other cell type. Our 3D system provides a structure that exploits embryonic processes such as tissue induction and condensation. We observed a unique phenomenon: the budding of co-culture pellets and the formation of satellite pellets that separate from the main pellet. MSC and NPC co-culture pellets were formed with three different structural organizations. The first had random organization. The other two had bilaminar organization with either MSC inside and NPC outside or NPC inside and MSC outside. By 14 days, all co-culture pellets exhibited budding and spontaneously generated satellite pellets. The satellite pellets were composed of both cell types and, surprisingly, all had the same bilaminar organization with MSC on the inside and NPC on the outside. This organization was independent of the structure of the main pellet that the satellites stemmed from. The main pellets generated satellite pellets that spontaneously organized into a bilaminar structure. This implies that structural organization occurs naturally in this cell culture system and may be inherently favorable for cell-based tissue engineering strategies. The occurrence of budding and the organization of satellite pellets may have important implications for the use of co-culture pellets in cell-based therapies for disc regeneration. From a therapeutic point of view, the generation of satellite pellets may be a beneficial feature that would serve to spread donor cells throughout the host matrix and restore normal matrix composition in a sustainable way, ultimately renewing tissue function.
Haubner, Frank; Leyh, Michaela; Ohmann, Elisabeth; Pohl, Fabian; Prantl, Lukas; Gassner, Holger G
The inflammatory response clinically observed after radiation has been described to correlate with elevated expression of cytokines and adhesion molecules by endothelial cells. Therapeutic compensation for this microvascular compromise could be an important approach in the treatment of irradiated wounds. Clinical reports describe the potential of adipose-derived stem cells to enhance wound healing, but the underlying cellular mechanisms remain largely unclear. Human dermal microvascular endothelial cells (HDMEC) and human adipose-derived stem cells (ASC) were cultured in a co-culture setting and irradiated with sequential doses of 2 to 12 Gy. Cell count was determined 48 h after radiation using a semi-automated cell counting system. Levels of interleukin-6 (IL-6), basic fibroblast growth factor (FGF), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were determined in the supernatants using enzyme-linked immunosorbent assay (ELISA). Irradiated HDMEC and ASC as well as non-irradiated co-cultures, HDMEC or ASC respectively were used as controls. Cell count was significantly reduced in irradiated co-cultures of HDMEC and ASC compared to non-irradiated controls. Levels of IL-6, FGF, ICAM-1 and VCAM-1 in the supernatants of the co-cultures were significantly less affected by external radiation in comparison to HDMEC. The increased expression of cytokines and adhesion molecules by HDMEC after external radiation is mitigated in the co-culture setting with ASC. These in vitro changes seem to support the clinical observation that ASC may have a stabilizing effect when injected into irradiated wounds
Full Text Available The development of effective and alternative tissue-engineered skin replacements to autografts, allografts and xenografts has became a clinical requirement due to the problems related to source of donor tissue and the perceived risk of disease transmission. In the present study 3D tissue engineered construct of sericin is developed using co-culture of keratinocytes on the upper surface of the fabricated matrices and with fibroblasts on lower surface. Sericin is obtained from "Sericin Hope" silkworm of Bombyx mori mutant and is extracted from cocoons by autoclave. Porous sericin matrices are prepared by freeze dried method using genipin as crosslinker. The matrices are characterized biochemically and biophysically. The cell proliferation and viability of co-cultured fibroblasts and keratinocytes on matrices for at least 28 days are observed by live/dead assay, Alamar blue assay, and by dual fluorescent staining. The growth of the fibroblasts and keratinocytes in co-culture is correlated with the expression level of TGF-β, b-FGF and IL-8 in the cultured supernatants by enzyme-linked immunosorbent assay. The histological analysis further demonstrates a multi-layered stratified epidermal layer of uninhibited keratinocytes in co-cultured constructs. Presence of involucrin, collagen IV and the fibroblast surface protein in immuno-histochemical stained sections of co-cultured matrices indicates the significance of paracrine signaling between keratinocytes and fibroblasts in the expression of extracellular matrix protein for dermal repair. No significant amount of pro inflammatory cytokines (TNF-α, IL-1β and nitric oxide production are evidenced when macrophages grown on the sericin matrices. The results all together depict the potentiality of sericin 3D matrices as skin equivalent tissue engineered construct in wound repair.
Knowlton, Stephanie; Yu, Chu Hsiang; Ersoy, Fulya; Emadi, Sharareh; Khademhosseini, Ali; Tasoglu, Savas
Three-dimensional (3D) printing offers potential to fabricate high-throughput and low-cost fabrication of microfluidic devices as a promising alternative to traditional techniques which enables efficient design iterations in the development stage. In this study, we demonstrate a single-step fabrication of a 3D transparent microfluidic chip using two alternative techniques: a stereolithography-based desktop 3D printer and a two-step fabrication using an industrial 3D printer based on polyjet technology. This method, compared to conventional fabrication using relatively expensive materials and labor-intensive processes, presents a low-cost, rapid prototyping technique to print functional 3D microfluidic chips. We enhance the capabilities of 3D-printed microfluidic devices by coupling 3D cell encapsulation and spatial patterning within photocrosslinkable gelatin methacryloyl (GelMA). The platform presented here serves as a 3D culture environment for long-term cell culture and growth. Furthermore, we have demonstrated the ability to print complex 3D microfluidic channels to create predictable and controllable fluid flow regimes. Here, we demonstrate the novel use of 3D-printed microfluidic chips as controllable 3D cell culture environments, advancing the applicability of 3D printing to engineering physiological systems for future applications in bioengineering.
Full Text Available The cooperative adaptation of subcultivated Bacillus cereus and Ketogulonicigenium vulgare significantly increased the productivity of 2-keto-L-gulonic acid, the precursor of vitamin C. The mechanism of cooperative adaptation of the serial subcultivated B. cereus and K. vulgare was investigated in this study by culturing the two strains orthogonally on agar plates. It was found that the swarming distance of B. cereus along the trace of K. vulgare on the plate decreased after 150 days' subcultivation. Metabolomic analysis on these co-cultured B. cereus and K. vulgare strains showed that their cooperative adaptation was accomplished by three key events: (i the ability of nutrients (e.g., amino acids and purines searching and intaking, and proteins biosynthesis is increased in the evolved B. cereus; (ii the capability of protein degradation and amino acids transportation is enhanced in evolved K. vulgare; (iii the evolved B. cereus was found to provide more nutrients (mostly amino acids and purines to K. vulgare, thus strengthening the oxidation and energy generation of K. vulgare. Our results provided novel insights into the systems-level understanding of the cooperative adaptation between strains in synergistic consortium.
Lai, Xianyin; Agarwal, Mangilal; Lvov, Yuri M; Pachpande, Chetan; Varahramyan, Kody; Witzmann, Frank A
Halloysite is aluminosilicate clay with a hollow tubular structure with nanoscale internal and external diameters. Assessment of halloysite biocompatibility has gained importance in view of its potential application in oral drug delivery. To investigate the effect of halloysite nanotubes on an in vitro model of the large intestine, Caco-2/HT29-MTX cells in monolayer co-culture were exposed to nanotubes for toxicity tests and proteomic analysis. Results indicate that halloysite exhibits a high degree of biocompatibility characterized by an absence of cytotoxicity, in spite of elevated pro-inflammatory cytokine release. Exposure-specific changes in expression were observed among 4081 proteins analyzed. Bioinformatic analysis of differentially expressed protein profiles suggest that halloysite stimulates processes related to cell growth and proliferation, subtle responses to cell infection, irritation and injury, enhanced antioxidant capability, and an overall adaptive response to exposure. These potentially relevant functional effects warrant further investigation in in vivo models and suggest that chronic or bolus occupational exposure to halloysite nanotubes may have unintended outcomes. Copyright © 2013 John Wiley & Sons, Ltd.
Khan, Nymul; Maezato, Yukari; McClure, Ryan S.; Brislawn, Colin J.; Mobberley, Jennifer M.; Isern, Nancy; Chrisler, William B.; Markillie, Lye Meng; Barney, Brett M.; Song, Hyun-Seob; Nelson, William C.; Bernstein, Hans C.
The fundamental question of whether different microbial species will co-exist or compete in a given environment depends on context, composition and environmental constraints. Model microbial systems can yield some general principles related to this question. In this study we employed a naturally occurring co-culture composed of heterotrophic bacteria, Halomonas sp. HL-48 and Marinobacter sp. HL-58, to ask two fundamental scientific questions: 1) how do the phenotypes of two naturally co-existing species respond to partnership as compared to axenic growth? and 2) how do growth and molecular phenotypes of these species change with respect to competitive and commensal interactions? We hypothesized – and confirmed – that co-cultivation under glucose as the sole carbon source would result in a competitive interactions. Similarly, when glucose was swapped with xylose, the interactions became commensal because Marinobacter HL-58 was supported by metabolites derived from Halomonas HL-48. Each species responded to partnership by changing both its growth and molecular phenotype as assayed via batch growth kinetics and global transcriptomics. These phenotypic responses depended nutrient availability and so the environment ultimately controlled how they responded to each other. This simplified model community revealed that microbial interactions are context-specific and different environmental conditions dictate how interspecies partnerships will unfold.
Reza Narenji Sani
Full Text Available The complex process of spermatogenesis is regulated by various factors. Studies onspermatogonial stem cells(SCCshave provided very important tool to improve herd geneticand different field. 0.2 to 0.3 percent of total cells of seminiferous tubules is consist ofspermatogonial stem cells. To investigate and biomanipulation of these cells, proliferationand viability rate of cells should be increasedin vitro, at first. Follicle stimulating hormone(FSH has been suggested to play a determinant role in the survival of germ cells in additionto increasing spermatogonial proliferation. In this study, thein vitroeffects ofFSHonspermatogonial cell colony formation were investigated. Sertoli and spermatogonial cellswere isolated from 3-5 months old calves. The identity of theSertoli cells and spermatogonialstem cells were confirmed through immunocytochemistry and colony morphology,respectively. Co-cultured Sertoli and spermatogonial cells were treatedwithFSHin differentdose of10, 20 and 40 IU mL-1FSH, before colony assay.Results indicated that,FSHincreasedin vitrocolonization of spermatogonial cells in comparison with control group. In conclusion,usingFSHprovided proper bovine spermatogonial stem cell culture medium forin vitrostudy of these cells.
Narenji Sani, Reza; Tajik, Parviz; Yousefi, Mohammad Hassan; Movahedin, Mansoureh; Qasemi-Panahi, Babak; Shafiei, Shiva; Ahmadi Hamedani, Mahmood
The complex process of spermatogenesis is regulated by various factors. Studies on spermatogonial stem cells (SCCs) have provided very important tool to improve herd genetic and different field. 0.2 to 0.3 percent of total cells of seminiferous tubules is consist of spermatogonial stem cells. To investigate and biomanipulation of these cells, proliferation and viability rate of cells should be increased in vitro, at first. Follicle stimulating hormone (FSH) has been suggested to play a determinant role in the survival of germ cells in addition to increasing spermatogonial proliferation. In this study, the in vitro effects of FSH on spermatogonial cell colony formation were investigated. Sertoli and spermatogonial cells were isolated from 3-5 months old calves. The identity of the Sertoli cells and spermatogonial stem cells were confirmed through immunocytochemistry and colony morphology, respectively. Co-cultured Sertoli and spermatogonial cells were treated with FSH in different dose of 10, 20 and 40 IU mL(-1) FSH, before colony assay. Results indicated that, FSH increased in vitro colonization of spermatogonial cells in comparison with control group. In conclusion, using FSH provided proper bovine spermatogonial stem cell culture medium for in vitro study of these cells.
Kim, Jaeyun; Bencherif, Sidi A; Li, Weiwei Aileen; Mooney, David J
Three-dimensional macroporous scaffolds have extensively been studied for cell-based tissue engineering but their use is mostly limited to mechanical support for cell adhesion and growth on the surface of macropores. Here, a templated fabrication method is described to prepare cell-friendly inverse opal-like hydrogels (IOHs) allowing both cell encapsulation within the hydrogel matrix and cell seeding on the surface of macropores. Ionically crosslinked alginate microbeads and photocrosslinkable biocompatible polymers are used as a sacrificial template and as a matrix, respectively. The alginate microbeads are easily removed by a chelating agent, with minimal toxicity for the encapsulated cells during template removal. The outer surface of macropores in IOHs can also provide a space for cell adherence. The cells encapsulated or attached in IOHs are able to remain viable and to proliferate over time. The elastic modulus and cell-adhesion properties of IOHs can be easily controlled and tuned. Finally, it is demonstrated that IOH can be used to co-culture two distinct cell populations in different spatial positions. This cell-friendly IOH system provides a 3D scaffold for organizing different cell types in a controllable microenvironment to investigate biological processes such as stem cell niches or tumor microenvironments. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Halai, Mansur; Ker, Andrew; Meek, Rm Dominic; Nadeem, Danish; Sjostrom, Terje; Su, Bo; McNamara, Laura E; Dalby, Matthew J; Young, Peter S
In biomaterial engineering, the surface of an implant can influence cell differentiation, adhesion and affinity towards the implant. On contact with an implant, bone marrow-derived mesenchymal stromal cells demonstrate differentiation towards bone forming osteoblasts, which can improve osteointegration. The process of micropatterning has been shown to improve osteointegration in polymers, but there are few reports surrounding ceramics. The purpose of this study was to establish a co-culture of bone marrow-derived mesenchymal stromal cells with osteoclast progenitor cells and to observe the response to micropatterned zirconia toughened alumina ceramics with 30 µm diameter pits. The aim was to establish whether the pits were specifically bioactive towards osteogenesis or were generally bioactive and would also stimulate osteoclastogenesis that could potentially lead to osteolysis. We demonstrate specific bioactivity of micropatterns towards osteogenesis, with more nodule formation and less osteoclastogenesis compared to planar controls. In addition, we found that that macrophage and osteoclast-like cells did not interact with the pits and formed fewer full-size osteoclast-like cells on the pitted surfaces. This may have a role when designing ceramic orthopaedic implants.
Sarman Oktovianus Gultom
Full Text Available Microalgae harvesting is a labor- and energy-intensive process and new approaches to harvesting microalgae need to be developed in order to decrease the costs. In this study; co-cultivatation of filamentous fungus (Aspergillus niger and microalgae (Chlorella vulgaris to form cell pellets was evaluated under different conditions, including organic carbon source (glucose; glycerol; and sodium acetate concentration; initial concentration of fungal spores and microalgal cells and light. Results showed that 2 g/L of glucose with a 1:300 ratio of fungi to microalgae provided the best culturing conditions for the process to reach >90% of cell harvest efficiency. The results also showed that an organic carbon source was required to sustain the growth of fungi and form the cell pellets. The microalgae/fungi co-cultures at mixotrophic conditions obtained much higher total biomass than pure cultures of each individual strains; indicating the symbiotic relationship between two strains. This can benefit the microbial biofuel production in terms of cell harvest and biomass production.
Sanford, Roland; Kolbman, Dan; Song, Wei; Wu, Mingming; Ma, Minglin; Das, Moumita
During tissue morphogenesis, from formation of embryos to tumor progression, cells often live and migrate in a heterogeneous environment consisting of many types of cells. To understand how differences in cell mechanobiological properties impact cellular self-organization and migration, we study a co-culture model composed of two distinct cell types confined in a three-dimensional spherical capsule. The cells are modeled as deformable, interacting, self-propelled particles that proliferate at specified timescales. A disordered potential is introduced to mimic the effect of the extracellular matrix (ECM). By varying the mechano-adhesive properties of each type, we investigate how differences in cell stiffness, cell-cell adhesion, and cell-ECM interaction influence collective properties of the binary cell population, such as self-assembly and migration. The predictions of the model are compared to experimental results on co-cutures of breast cancer cells and non-tumorigenic breast epithelial cells. This work was partially supported by a Cottrell College Science Award from the Research Corporation for Science Advancement.
Hjelholt, Morten; Damsgaard, Jan
thoroughly and substitute current payment standards in the decades to come. This paper portrays how digital payment platforms evolve in socio-technical niches and how various technological platforms aim for institutional attention in their attempt to challenge earlier platforms and standards. The paper...... applies a co-evolutionary multilevel perspective to model the interplay and processes between technology and society wherein digital payment platforms potentially will substitute other payment platforms just like the credit card negated the check. On this basis this paper formulate a multilevel conceptual...
Hendriks, J.A.A.; Miclea, Razvan L.; Schotel, Roka; de Bruijn, Ewart; Moroni, Lorenzo; Karperien, Hermanus Bernardus Johannes; Riesle, J.U.; van Blitterswijk, Clemens
Co-culture models have been increasingly used in tissue engineering applications to understand cell–cell interactions and consequently improve regenerative medicine strategies. Aiming at further elucidating cartilage tissue formation, we co-cultured bovine primary chondrocytes (BPCs) with human
Issadore, David; Franke, Thomas; Brown, Keith A; Westervelt, Robert M
We present an integrated platform for performing biological and chemical experiments on a chip based on standard CMOS technology. We have developed a hybrid integrated circuit (IC)/microfluidic chip that can simultaneously control thousands of living cells and pL volumes of fluid, enabling a wide variety of chemical and biological tasks. Taking inspiration from cellular biology, phospholipid bilayer vesicles are used as robust picolitre containers for reagents on the chip. The hybrid chip can be programmed to trap, move, and porate individual living cells and vesicles and fuse and deform vesicles using electric fields. The IC spatially patterns electric fields in a microfluidic chamber using 128 × 256 (32,768) 11 × 11 μm(2) metal pixels, each of which can be individually driven with a radio frequency (RF) voltage. The chip's basic functions can be combined in series to perform complex biological and chemical tasks and can be performed in parallel on the chip's many pixels for high-throughput operations. The hybrid chip operates in two distinct modes, defined by the frequency of the RF voltage applied to the pixels: Voltages at MHz frequencies are used to trap, move, and deform objects using dielectrophoresis and voltages at frequencies below 1 kHz are used for electroporation and electrofusion. This work represents an important step towards miniaturizing the complex chemical and biological experiments used for diagnostics and research onto automated and inexpensive chips.
Cheng, Shi; Wu, Zhigang
Stretchable electronics is a revolutionary technology that will potentially create a world of radically different electronic devices and systems that open up an entirely new spectrum of possibilities. This article proposes a microfluidic based solution for stretchable radio frequency (RF) electronics, using hybrid integration of active circuits assembled on flex foils and liquid alloy passive structures embedded in elastic substrates, e.g. polydimethylsiloxane (PDMS). This concept was employed to implement a 900 MHz stretchable RF radiation sensor, consisting of a large area elastic antenna and a cluster of conventional rigid components for RF power detection. The integrated radiation sensor except the power supply was fully embedded in a thin elastomeric substrate. Good electrical performance of the standalone stretchable antenna as well as the RF power detection sub-module was verified by experiments. The sensor successfully detected the RF radiation over 5 m distance in the system demonstration. Experiments on two-dimensional (2D) stretching up to 15%, folding and twisting of the demonstrated sensor were also carried out. Despite the integrated device was severely deformed, no failure in RF radiation sensing was observed in the tests. This technique illuminates a promising route of realizing stretchable and foldable large area integrated RF electronics that are of great interest to a variety of applications like wearable computing, health monitoring, medical diagnostics, and curvilinear electronics.
Full Text Available Flow-based microfluidic systems have been widely utilized for cell migration studies given their ability to generate versatile and precisely defined chemical gradients and to permit direct visualization of migrating cells. Nonetheless, the general need for bulky peripherals such as mechanical pumps and tubing and the complicated setup procedures significantly limit the widespread use of these microfluidic systems for cell migration studies. Here we present a simple method to power microfluidic devices for chemotaxis assays using the commercially available ALZET® osmotic pumps. Specifically, we developed a standalone chemotaxis platform that has the same footprint as a multiwell plate and can generate well-defined, stable chemical gradients continuously for up to 7 days. Using this platform, we validated the short-term (24 hours and long-term (72 hours concentration dependent PDGF-BB chemotaxis response of human bone marrow derived mesenchymal stem cells.
Luo, Hongzhen; Ge, Laibing; Zhang, Jingshu; Ding, Jian; Chen, Rui; Shi, Zhongping
Acetone is the major by-product in ABE fermentations, most researches focused on increasing butanol/acetone ratio by decreasing acetone biosynthesis. However, economics of ABE fermentation industry strongly relies on evaluating acetone as a valuable platform chemical. Therefore, a novel ABE fermentation strategy focusing on bio-acetone production by co-culturing Clostridium acetobutylicum/Saccharomyces cerevisiae with exogenous acetate addition was proposed. Experimental and theoretical analysis revealed the strategy could, enhance C. acetobutylicum survival oriented amino acids assimilation in the cells; control NADH regeneration rate at moderately lower level to enhance acetone synthesis but without sacrificing butanol production; enhance the utilization ability of C. acetobutylicum on glucose and direct most of extra consumed glucose into acetone/butanol synthesis routes. By implementing the strategy using synthetic or acetate fermentative supernatant, acetone concentrations increased to 8.27-8.55g/L from 5.86g/L of the control, while butanol concentrations also elevated to the higher levels of 13.91-14.23g/L from 11.63g/L simultaneously. Copyright © 2015 Elsevier Ltd. All rights reserved.
Sung Kuk Lee
Full Text Available Microfluidic technologies have shown powerful abilities for reducing cost, time, and labor, and at the same time, for increasing accuracy, throughput, and performance in the analysis of biological and biochemical samples compared with the conventional, macroscale instruments. Synthetic biology is an emerging field of biology and has drawn much attraction due to its potential to create novel, functional biological parts and systems for special purposes. Since it is believed that the development of synthetic biology can be accelerated through the use of microfluidic technology, in this review work we focus our discussion on the latest microfluidic technologies that can provide unprecedented means in synthetic biology for dynamic profiling of gene expression/regulation with high resolution, highly sensitive on-chip and off-chip detection of metabolites, and whole-cell analysis.
Wantiya, P.; Burger, Robert; Alstrøm, Tommy Sonne
In this work we present a magnetic micro beads based agglutination assay on a centrifugal microfluidic platform. An imaging based method is used to quantify bead agglutination and measure the concentration of antibodies or C-reactive protein in solution.......In this work we present a magnetic micro beads based agglutination assay on a centrifugal microfluidic platform. An imaging based method is used to quantify bead agglutination and measure the concentration of antibodies or C-reactive protein in solution....
Amato, Letizia; Kuldeep, Kuldeep; Esmail Tehrani, Sheida
In this work, we demonstrate an integrated electrochemical system on a centrifugal microfluidic platform for cell studies by combining electrochemical impedance spectroscopy and amperometry, and comparison of different cleaning protocols for gold electrodes on plastic substrate.......In this work, we demonstrate an integrated electrochemical system on a centrifugal microfluidic platform for cell studies by combining electrochemical impedance spectroscopy and amperometry, and comparison of different cleaning protocols for gold electrodes on plastic substrate....
Zhu, Ning; Lin, Jizong; Wang, Kewan; Wei, Meidan; Chen, Qingzhuang; Wang, Yong
Objectives: This study aims to explore whether Huperzine A (HupA) could protect neural stem cells against amyloid beta-peptide Aβ induced apoptosis in a neural stem cells (NSCs) and microglia co-culture system. Methods: Rat NSCs and microglial cells were isolated, cultured and identified with immunofluorescence Assays (IFA). Co-culture systems of NSCs and microglial cells were employed using Transwell Permeable Supports. The effects of Aβ1-42 on NSCs were studied in 4 groups using co-culture systems: NSCs, Aβ+NSCs, co-culture and Aβ+co-culture groups. Bromodeoxyuridine (BrdU) incorporation and flow cytometry were utilized to assess the differences of proliferation, differentiation and apoptosis of NSCs between the groups. LQ test was performed to assess the amounts of IL-6, TNF-α and MIP-α secreted, and flow cytometry and Western blotting were used to assess apoptosis of NSCs and the expressions of Bcl-2 and Bax in each group. Results: IFA results showed that isolated rat NSCs were nestin-positive and microglial cells were CD11b/c-positive. Among all the groups, the Aβ+co-culture group has the lowest BrdU expression level, the lowest MAP2-positive, ChAT-positive cell counts and the highest NSC apoptosis rate. Smaller amounts of IL-6, TNF-α and MIP-α were being secreted by microglial cells in the HupA+Aβ+co-culture group compared with those in the Aβ+ co-culture group. Also the Bcl-2: Bax ratio was much higher in the HupA+Aβ+co-culture group than in the Aβ+co-culture group. Conclusions: HupA inhibits cell apoptosis through restraining microglia’s inflammatory response induced by Aβ1-42. PMID:26261518
Exploiting flow on the micron-scale is emerging as a method to probe cell mechanical properties with 10-1000x advances in throughput over existing technologies. The mechanical properties of cells and the cell nucleus are implicated in a wide range of biological contexts: for example, the ability of white blood cells to deform is central to immune response; and malignant cells show decreased stiffness compared to benign cells. We recently developed a microfluidic device to probe cell and nucleus mechanical properties: cells are forced to deform through a narrow constrictions in response to an applied pressure; flowing cells through a series of constrictions enables us to probe the ability of hundreds of cells to deform and relax during flow. By tuning the constriction width so it is narrower than the width of the cell nucleus, we can specifically probe the effects of nuclear physical properties on whole cell deformability. We show that the nucleus is the rate-limiting step in cell passage: inducing a change in its shape to a multilobed structure results in cells that transit more quickly; increased levels of lamin A, a nuclear protein that is key for nuclear shape and mechanical stability, impairs the passage of cells through constrictions. We are currently developing a new class of microfluidic devices to simultaneously probe the deformability of hundreds of cell samples in parallel. Using the same soft lithography techniques, membranes are fabricated to have well-defined pore distribution, width, length, and tortuosity. We design the membranes to interface with a multiwell plate, enabling simultaneous measurement of hundreds of different samples. Given the wide spectrum of diseases where altered cell and nucleus mechanical properties are implicated, such a platform has great potential, for example, to screen cells based on their mechanical phenotype against a library of drugs.
Song, Linyang; Song, Wei; Schipper, Hyman M
The mechanisms responsible for the progressive degeneration of dopaminergic neurons and pathologic iron deposition in the substantia nigra pars compacta of patients with Parkinson's disease (PD) remain unclear. Heme oxygenase-1 (HO-1), the rate-limiting enzyme in the oxidative degradation of heme to ferrous iron, carbon monoxide, and biliverdin, is upregulated in affected PD astroglia and may contribute to abnormal mitochondrial iron sequestration in these cells. To determine whether glial HO-1 hyper-expression is toxic to neuronal compartments, we co-cultured dopaminergic PC12 cells atop monolayers of human (h) HO-1 transfected, sham-transfected, or non-transfected primary rat astroglia. We observed that PC12 cells grown atop hHO-1 transfected astrocytes, but not the astroglia themselves, were significantly more susceptible to dopamine (1 microM) + H(2)O(2) (1 microM)-induced death (assessed by nuclear ethidium monoazide bromide staining and anti-tyrosine hydroxylase immunofluorescence microscopy) relative to control preparations. In the experimental group, PC12 cell death was attenuated significantly by the administration of the HO inhibitor, SnMP (1.5 microM), the antioxidant, ascorbate (200 microM), or the iron chelators, deferoxamine (400 microM), and phenanthroline (100 microM). Exposure to conditioned media derived from HO-1 transfected astrocytes also augmented PC12 cell killing in response to dopamine (1 microM) + H(2)O(2) (1 microM) relative to control media. In PD brain, overexpression of HO-1 in nigral astroglia and accompanying iron liberation may facilitate the bioactivation of dopamine to neurotoxic free radical intermediates and predispose nearby neuronal constituents to oxidative damage. (c) 2007 Wiley-Liss, Inc.
Schmaltz-Panneau, Barbara; Cordova, Amanda; Dhorne-Pollet, Sophie; Hennequet-Antier, Christelle; Uzbekova, Sveltlana; Martinot, Emmanuelle; Doret, Sarah; Martin, Patrice; Mermillod, Pascal; Locatelli, Yann
In mammals, the oviduct may participate to the regulation of early embryo development. In vitro co-culture of early bovine embryos with bovine oviduct epithelial cells (BOEC) has been largely used to mimic the maternal environment. However, the mechanisms of BOEC action have not been clearly elucidated yet. The aim of this study was to determine the response of BOEC cultures to the presence of developing bovine embryos. A 21,581-element bovine oligonucleotide array was used compare the gene expression profiles of confluent BOEC cultured for 8 days with or without embryos. This study revealed 34 differentially expressed genes (DEG). Of these 34 genes, IFI6, ISG15, MX1, IFI27, IFI44, RSAD2, IFITM1, EPSTI1, USP18, IFIT5, and STAT1 expression increased to the greatest extent due to the presence of embryos with a major impact on antiviral and immune response. Among the mRNAs at least 25 are already described as induced by interferons. In addition, transcript levels of new candidate genes involved in the regulation of transcription, modulation of the maternal immune system and endometrial remodeling were found to be increased. We selected 7 genes and confirmed their differential expression by quantitative RT-PCR. The immunofluorescence imaging of cellular localization of STAT1 protein in BOEC showed a nuclear translocation in the presence of embryos, suggesting the activation of interferon signaling pathway. This first systematic study of BOEC transcriptome changes in response to the presence of embryos in cattle provides some evidences that these cells are able to adapt their transcriptomic profile in response to embryo signaling. Copyright © 2014 Elsevier B.V. All rights reserved.
Case, Daniel; Angilella, Jean-Regis; Motter, Adilson
Precisely controlling flows within microfluidic systems is often difficult which typically results in systems being heavily reliant on numerous external pumps and computers. Here, I present a simple microfluidic network that exhibits flow rate switching, bistablity, and spontaneous oscillations controlled by a single pressure. That is, by solely changing the driving pressure, it is possible to switch between an oscillating and steady flow state. Such functionality does not rely on external hardware and may even serve as an on-chip memory or timing mechanism. I use an analytic model and rigorous fluid dynamics simulations to show these results.
Beebe, David J. (Inventor); MacDonald, Michael J. (Inventor); Eddington, David T. (Inventor); Mensing, Glennys A. (Inventor)
A microfluidic device is provided for delivering a drug to an individual. The microfluidic device includes a body that defines a reservoir for receiving the drug therein. A valve interconnects the reservoir to an output needle that is insertable into the skin of an individual. A pressure source urges the drug from the reservoir toward the needle. The valve is movable between a closed position preventing the flow of the drug from the reservoir to the output needle and an open position allowing for the flow of the drug from the reservoir to the output needle in response to a predetermined condition in the physiological fluids of the individual.
Microfluidic applications hold promise for many different end‐users both within and outside, and across many different research communities. Despite the benefits of microfluidic approaches, adoption and implementation thereof is often hindered by practical issues. Microfluidic components which......‐integrated interconnection and miniaturized peristaltic pump solutions were then combined into modular microfluidic systems. One system provides high interconnection numbers/density and allows many possible configurations. Additionally, and apart from many other accounts of modular microfluidic solutions, methods...... for control and actuation of microfluidic networks built from the modular components is described. Prototypes of the microfluidic system have begun to be distributed to external collaborators and researcher parties. These end‐users will assist in the validation of the approach and ultimately fulfil the key...
Choi, Ji Wook; Lee, Jong Min; Kim, Tae Hyun; Ha, Jang Ho; Ahrberg, Christian D.; Chung, Bong Geun
The droplet-generating microfluidics has become an important technique for a variety of applications ranging from single cell analysis to nanoparticle synthesis. Although there are a large number of methods for generating and experimenting with droplets on microfluidic devices, the dispensing of droplets from these microfluidic devices is a challenge due to aggregation and merging of droplets at the interface of microfluidic devices. Here, we present a microfluidic dual-nozzle device for the generation and dispensing of uniform-sized droplets. The first nozzle of the microfluidic device is used for the generation of the droplets, while the second nozzle can accelerate the droplets and increase the spacing between them, allowing for facile dispensing of droplets. Computational fluid dynamic simulations were conducted to optimize the design parameters of the microfluidic device.
Staykova, Kalina Stefanova; Damsgaard, Jan
This research paper presents an initial attempt to introduce and explain the emergence of new phenomenon, which we refer to as platform constellations. Functioning as highly modular systems, the platform constellations are collections of highly connected platforms which co-exist in parallel and a......’ acquisition and users’ engagement rates as well as unlock new sources of value creation and diversify revenue streams....
Resto, Pedro J; Bhat, Abhishek; Stava, Eric; Lor, Chong; Merriam, Elliot; Diaz-Rivera, Ruben E; Pearce, Robert; Blick, Robert; Williams, Justin C
Surface tension passive pumping is a way to actuate flow without the need for pumps, tubing or valves by using the pressure inside small drop to move liquid via a microfluidic channel. These types of tubeless devices have typically been used in cell biology. Herein we present the use of tubeless devices as a fluid exchange platform for patch clamp electrophysiology. Inertia from high-speed droplets and jets is used to create flow and perform on-the-fly mixing of solutions. These are then flowed over GABA transfected HEK cells under patch in order to perform a dose response analysis. TIRF imaging and electrical recordings are used to study the fluid exchange properties of the microfluidic device, resulting in 0-90% fluid exchange times of hundreds of milliseconds. COMSOL is used to model flow and fluid exchange within the device. Patch-clamping experiments show the ability to use high-speed passive pumping and its derivatives for studying peak dose responses, but not for studying ion channel kinetics. Our system results in fluid exchange times slower than when using a standard 12-barrel application system and is not as stable as traditional methods, but it offers a new platform with added functionality. Surface tension passive pumping and tubeless devices can be used in a limited fashion for electrophysiology. Users may obtain peak dose responses but the system, in its current form, is not capable of fluid exchange fast enough to study the kinetics of most ion channels. Copyright © 2017 Elsevier B.V. All rights reserved.
The rapid advances in microfabrication and nanofabrication in combination with the synthesis and discovery of new materials have propelled the drive to develop new technological devices such as smartphones, personal and tablet computers. These devices have changed the way humankind interacts......TAS technologies need to join forces with those behind the new communication devices which provide sources of power, detection and data transmission complementing the features that lab-on-a-chip and microTAS platforms can offer. An increasing number of microfluidic-based devices, developed both in small start...
Retterer, Scott T [ORNL; Doktycz, Mitchel John [ORNL
The portability and personalization of health-care diagnostics and treatments benefits from advancements and applications of micro and nanotechnology. Modularization and miniaturization of standardized biochemical processes and tests facilitates the advancement and customization of analyte detection and diagnosis on-chip. The goal of our work here is to develop modular platforms for on-chip biochemical processing of synthesized biologics for a range of on-demand applications. Our report focuses on the initial development, characterization and application of microfluidic size exclusion/gel filtration and ion exchange protein concentration modules for cytokine isolation from spiked cell extracts.
Mashraei, Yousof; Sivashankar, Shilpa; Buttner, Ulrich; Salama, Khaled N.
fractal electrode biosensor that is used for both droplet actuation and sensing C-reactive protein (CRP) concentration levels to assess cardiac disease risk. Our proposed electrode is the first two-terminal electrode design to be integrated into DMF
Mashraei, Yousof; Sivashankar, Shilpa; Buttner, Ulrich; Salama, Khaled N.
the concentration levels of C-reactive protein (CRP) to determine the risk of cardiovascular disease. The capacitance increased sevenfold and stabilized in less than 5 minutes. The sensor shows a decreasing trend of capacitance readouts with the increase
Botulinum neurotoxin – a global public health threat and category A bioterrorism agent - is the most toxic substance known and one of the most challenging toxins to detect due to its lethality at extremely low concentrations. Hence the live-mouse bioassay because of its superior sensitivity, remains...
Perrault, C M; Qasaimeh, M A; Brastaviceanu, T; Anderson, K; Kabakibo, Y; Juncker, D
The microfluidic probe (MFP) consists of a flat, blunt tip with two apertures for the injection and reaspiration of a microjet into a solution--thus hydrodynamically confining the microjet--and is operated atop an inverted microscope that enables live imaging. By scanning across a surface, the microjet can be used for surface processing with the capability of both depositing and removing material; as it operates under immersed conditions, sensitive biological materials and living cells can be processed. During scanning, the MFP is kept immobile and centered over the objective of the inverted microscope, a few micrometers above a substrate that is displaced by moving the microscope stage and that is flushed continuously with the microjet. For consistent and reproducible surface processing, the gap between the MFP and the substrate, the MFP's alignment, the scanning speed, the injection and aspiration flow rates, and the image capture need all to be controlled and synchronized. Here, we present an automated MFP station that integrates all of these functionalities and automates the key operational parameters. A custom software program is used to control an independent motorized Z stage for adjusting the gap, a motorized microscope stage for scanning the substrate, up to 16 syringe pumps for injecting and aspirating fluids, and an inverted fluorescence microscope equipped with a charge-coupled device camera. The parallelism between the MFP and the substrate is adjusted using manual goniometer at the beginning of the experiment. The alignment of the injection and aspiration apertures along the scanning axis is performed using a newly designed MFP screw holder. We illustrate the integrated MFP station by the programmed, automated patterning of fluorescently labeled biotin on a streptavidin-coated surface.
Chávez-Gómez, B; Quintero, R; Esparza-García, F; Mesta-Howard, A M; Zavala Díaz de la Serna, F J; Hernández-Rodríguez, C H; Gillén, T; Poggi-Varaldo, H M; Barrera-Cortés, J; Rodríguez-Vázquez, R
Sixteen co-cultures composed of four bacteria and four fungi grown on sugarcane bagasse pith were tested for phenanthrene degradation in soil. The four bacteria were identified as Pseudomonas aeruginose, Ralstonia pickettii, Pseudomonas sp. and Pseudomonas cepacea. The four fungi were identified as: Penicillium sp., Trichoderma viride, Alternaria tenuis and Aspergillus terrus that were previously isolated from different hydrocarbon-contaminated soils. Fungi had a statistically significant positive (0.0001
Co-cultures B. cepacea-Penicillium sp., R. pickettii-Penicillium sp., and P. aeruginose-Penicillium sp. exhibited synergism for phenanthrene removal, reaching 72.84+/-3.85%, 73.61+/-6.38% and 69.47+/-4.91%; in 18 days, respectively.
Jantzen, Kim; Roursgaard, Martin; Madsen, Claus Desler
Studies in mono-culture of cells have shown that diesel exhaust particles (DEPs) increase the production of reactive oxygen species (ROS) and oxidative stress-related damage to DNA. However, the level of particle-generated genotoxicity may depend on interplay between different cell types, e.g. lung...... treatment with standard reference DEPs, SRM2975 and SRM1650b. The exposure to DEPs did not affect the colony-forming ability of A549 cells in co-culture with THP-1a cells. The DEPs generated DNA strand breaks and oxidatively damaged DNA, measured using the alkaline comet assay as formamidopyrimidine...... relationship between levels of respiration and ROS production. In conclusion, exposure of mono-cultured cells to DEPs generated oxidative stress to DNA, whereas co-cultures with macrophages had lower levels of oxidatively damaged DNA than A549 epithelial cells....
Horton, Renita E
SCD stems from amutation in the beta globin gene. Upon deoxygenation, hemoglobin polymerizes and triggers RBC remodeling. This phenomenon is central to SCD pathogenesis as individuals suffering from the disease are plagued by painful vaso-occlusive crises episodes. These episodes are the result of a combination of processes including inflammation, thrombosis, and blood cell adhesion to the vascular wall which leads to blockages within the vasculature termed vaso-occlusions. Vaso-occlusive episodes deprive tissues of oxygen and are a major contributor to SCD-related complications; unfortunately, the complex mechanisms that contribute to vaso-occlusions are not well understood. Vaso-occlusions can occur in post-capillary venules; hence, the microvasculature is a prime target for SCD therapies. Traditional in vitro systems poorly recapitulate architectural and dynamic flow properties of in vivo systems. However, microfluidic devices can capture features of the native vasculature such as cellular composition, flow, geometry, and ECM presentation. This review, although not comprehensive, highlights microfluidic approaches that aim to improve our current understanding of the pathophysiological mechanisms surrounding SCD. Microfluidic platforms can aid in identifying factors that may contribute to disease severity and can serve as suitable test beds for novel treatment strategies which may improve patient outcomes. © 2017 John Wiley & Sons Ltd.
Copenhaver, Thomas S; Purohit, Krutarth H; Domalaon, Kryls; Pham, Linda; Burgess, Brianna J; Manorothkul, Natalie; Galvan, Vicente; Sotez, Samantha; Gomez, Frank A; Haan, John L
We describe the first direct formate fuel cell on a paper microfluidic platform. In traditional membrane-less microfluidic fuel cells (MFCs), external pumping consumes power produced by the fuel cell in order to maintain co-laminar flow of the anode stream and oxidant stream to prevent mixing. However, in paper microfluidics, capillary action drives flow while minimizing stream mixing. In this work, we demonstrate a paper MFC that uses formate and hydrogen peroxide as the anode fuel and cathode oxidant, respectively. Using these materials we achieve a maximum power density of nearly 2.5 mW/mg Pd. In a series configuration, our MFC achieves an open circuit voltage just over 1 V, and in a parallel configuration, short circuit of 20 mA absolute current. We also demonstrate that the MFC does not require continuous flow of fuel and oxidant to produce power. We found that we can pre-saturate the materials on the paper, stop the electrolyte flow, and still produce approximately 0.5 V for 15 min. This type of paper MFC has potential applications in point-of-care diagnostic devices and other electrochemical sensors. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Ramezanifard, Rouhallah; Kabiri, Mahboubeh; Hanaee Ahvaz, Hana
Regarding the inadequate healing capability of cartilage tissue, cell-based therapy is making the future of cartilage repair and regeneration. Mesenchymal stem cells (MSC) have shown great promise in cartilage regeneration. However, a yet-unresolved issue is the emergence of hypertrophic and pathologic markers during in vitro MSC chondrogenesis. Articular chondrocytes (AC) can suppress the undesired hypertrophy when co-cultured with MSC. On the other hand, platelet rich plasma (PRP), is consi...
Taking into consideration the complex biology of bone tissue it is quite clear that the understanding of the cellular interactions that regulate the homeostasis and regeneration of this remarkable tissue is essential for a successful Tissue Engineering strategy. The in vitro study of these cellular interactions relies on co-culture systems, a tremendously useful methodology where two or more cell types are cultured at the same time. Such strategy increases the complexity of typ...
Kadow-Romacker, Anke; Duda, Georg N; Bormann, Nicole; Schmidmaier, Gerhard; Wildemann, Britt
Osteoblast- and osteoclast-like cells are responsible for coordinated bone maintenance, illustrated by a balanced formation and resorption. Both parameters appear to be influenced by mechanical constrains acting on each of these cell types individually. We hypothesized that the interactions between both cell types are also influenced by mechanical stimulation. Co-cultures of osteoblast- and osteoclast-like cells were stimulated with 1,100 µstrain, 0.1 or 0.3 Hz for 1-5 min/day over 5 days. Two different setups depending on the differentiation of the osteoclast-like cells were used: i) differentiation assay for the fusion of pre-osteoclasts to osteoclasts, ii) resorption assay to determine the activity level of osteoclast-like cells. In the differentiation assay (co-culture of osteoblasts with unfused osteoclast precursor cells) the mechanical stimulation resulted in a significant decrease of collagen-1 and osteocalcin produced by osteoblast-like cells. Significantly more TRAP-iso5b was measured after stimulation for 3 min with 0.1 Hz, indicating enhanced osteoclastogenesis. In the resorption assay (co-culture of osteoblasts with fused osteoclasts) the stimulation for 3 min with 0.3 Hz significantly increased the resorption activity of osteoclasts measured by the pit formation and the collagen resorption. The same mechanical stimulation resulted in an increased collagen-1 production by the osteoblast-like cells. The ratio of RANKL/OPG was not different between the groups. These findings demonstrate that already small changes in duration or frequency of mechanical stimulation had significant consequences for the behavior of osteoblast- and osteoclast-like cells in co-culture, which partially depend on the differentiation status of the osteoclast-like cells.
Bin Li; Muhammad Ibrahim; Mengyu Ge; Zhouqi Cui; Guochang Sun; Fei Xu; Michael Kube
Response of bacterial pathogen to environmental bacteria and its host is critical for understanding of microbial adaption and pathogenesis. Here, we used RNA-Seq to comprehensively and quantitatively assess the transcriptional response of Acidovorax avenae subsp. avenae strain RS-1 cultivated in vitro, in vivo and in co-culture with rice rhizobacterium Burkholderia seminalis R456. Results revealed a slight response to other bacteria, but a strong response to host. In particular, a large numbe...
Al-Shehri, Abdulghani; Favretto, Marco E; Ioannou, Panayiotis V; Romero, Ignacio A; Couraud, Pierre-Olivier; Weksler, Babette Barbash; Parker, Terry L; Kallinteri, Paraskevi
Owing to restricted access of pharmacological agents into the brain due to blood brain barrier (BBB) there is a need: 1. to develop a more representative 3-D-co-culture model of tumor-BBB interaction to investigate drug and nanoparticle transport into the brain for diagnostic and therapeutic evaluation. 2. to address the lack of new alternative methods to animal testing according to replacement-reduction-refinement principles. In this work, in vitro BBB-medulloblastoma 3-D-co-culture models were established using immortalized human primary brain endothelial cells (hCMEC/D3). hCMEC/D3 cells were cultured in presence and in absence of two human medulloblastoma cell lines on Transwell membranes. In vitro models were characterized for BBB formation, zonula occludens-1 expression and permeability to dextran. Transferrin receptors (Tfr) expressed on hCMEC/D3 were exploited to facilitate arsonoliposome (ARL) permeability through the BBB to the tumor by covalently attaching an antibody specific to human Tfr. The effect of anticancer ARLs on hCMEC/D3 was assessed. In vitro BBB and BBB-tumor co-culture models were established successfully. BBB permeability was affected by the presence of tumor aggregates as suggested by increased permeability of ARLs. There was a 6-fold and 8-fold increase in anti-Tfr-ARL uptake into VC312R and BBB-DAOY co-culture models, respectively, compared to plain ARLs. The three-dimensional models might be appropriate models to study the transport of various drugs and nanocarriers (liposomes and immunoarsonoliposomes) through the healthy and diseased BBB. The immunoarsonoliposomes can be potentially used as anticancer agents due to good tolerance of the in vitro BBB model to their toxic effect.
Saha, Arindam; Jana, Nikhil R
Although microfluidic approach is widely used in various point of care diagnostics, its implementation in surface enhanced Raman spectroscopy (SERS)-based detection is challenging. This is because SERS signal depends on plasmonic nanoparticle aggregation induced generation of stable electromagnetic hot spots and in currently available microfluidic platform this condition is difficult to adapt. Here we show that SERS can be adapted using simple paper based microfluidic system where both the plasmonic nanomaterials and analyte are used in mobile phase. This approach allows analyte induced controlled particle aggregation and electromagnetic hot spot generation inside the microfluidic channel with the resultant SERS signal, which is highly reproducible and sensitive. This approach has been used for reproducible detection of protein in the pico to femtomolar concentration. Presented approach is simple, rapid, and cost-effective, and requires low sample volume. Method can be extended for SERS-based detection of other biomolecules.
Ruemke, H.C.; Terpstra, F.G.; Huis, B.; Out, T.A.; Zeijlemaker, W.P.
When human peripheral blood lymphocytes (PBL) are cultured in the presence of irradiated allogeneic lymphocytes, the resulting mixed lymphocyte reaction (MLR) leads to the secretion into the supernatant of substantial amounts of IgM and IgG, derived from nonirradiated responder B lymphocytes. Our data indicate that stimulation to Ig production by responder B cells may result from different types of of interactions. First, B cells and monocytes among the irradiated stimulator cells activate T responder B cells to produce Ig; second, ''responder'' B cells activate irradiated ''stimulator'' T cells, leading to a ''helper'' signal, back to the responder B cells and leading to Ig production. The latter system is radiosensitive, because allogeneic T cells, irradiated at a dose of 4000 rad or more, failed to induce Ig production by responder B cells. In some combinations of human allogeneic lymphocytes, the co-culture of the cells leads to inhibition of Ig production, both in the presence and in the absence of PWM. Thus, co-culture of allogeneic cells may cause ''positive'' as well as ''negative'' allogeneic effects. The implications of these findings for the interpretation of co-cultures that are aimed at establishing defects in lymphocytes from patients with, for example, immunodeficiencies, who fail to produce Ig in the presence of PWM are discussed
Lombardi, Silvia Jane; De Leonardis, Antonella; Lustrato, Giuseppe; Testa, Bruno; Iorizzo, Massimo
Sparkling wines produced by traditional method owe their characteristics to secondary fermentation and maturation that occur during a slow ageing in bottles. Yeast autolysis plays an important role during the sparkling wine aging. Using a combination of killer and sensitive yeasts is possible to accelerate yeast autolysis and reduce maturing time. killer and sensitive Saccharomyces cerevisiae strains, separately and in co-cultures, were inoculated in base wine and bottled on pilot-plant scale. Commercial Saccaromyces bayanus strain was also investigated. Protein free amino acid and polysaccharides contents and sensory analysis were determined on the wine samples at 3, 6 and 9 months of aging. Yeast autolysis that occurs during the production of sparkling wines, obtained with co-cultures of killer and sensitive strains, has influenced free amino acids, total protein and polysaccharides content after 3 months aging time: sparkling wines, produced without the use of these yeasts, have reached the same results only after 9 months aging time. These results demonstrate that killer and sensitive yeasts in co-culture can accelerate the onset of autolysis in enological conditions, and has a positive effect on the quality of the aroma and flavor of sparkling wine. This paper offers an interesting biotechnological method to reduce production time of sparkling wine with economical benefits for the producers. We revised all patents relating to sparkling wine considering only those of interest for our study.
Abbasi, Ardeshir; Kukia, Nasim Rahmani; Froushani, Seyyed Meysam Abtahi; Hashemi, Seyed Mahmoud
Mesenchymal stem cells (MSCs) express some of the nicotinic receptor subunits and adenosine receptors. The communication between tissue MSCs with neutrophils has been shown in previous studies. The aim of the present study is to determine the role of nicotine or caffeine on MSCs and its effects on neutrophils. After the isolation, MSCs were pulsed with LPS (10 ng/ml) for 1 h. Then, MSCs were incubated with different concentrations of caffeine (0.1, 0.5 and 1 mM) and or with different concentrations of nicotine (0.1, 0.5, and 1 μM) for 48 h. Afterwards, the medium was aspirated and the cells were used for co-culture experiment with neutrophil. The obtained data showed that LPS primed MSCs could decrease neutrophil vitality, whereas the treatment of MSCs with nicotine and/or especially a treatment with caffeine reverse this effect. Obtained data showed that when the LPS-primed MSCs were treated with nicotine or caffeine, the vitality of co-cultured neutrophils was significantly increased. The rate of the respiratory burst of neutrophils after co-culture by LPS-primed MSCs was decreased compared to the respiratory burst of neutrophil alone. Nicotine and/or caffeine treatment could reverse this reduction. Generally, these findings provide a new insight into understanding the anti-inflammatory and immunomodulatory effects of nicotine and caffeine. Copyright © 2018 Elsevier Inc. All rights reserved.
Full Text Available The phytoestrogen puerarin has been shown to protect neurons and astrocytes in the brain, and is therefore an attractive drug in the treatment of Alzheimer′s disease, Parkinson′s disease and cerebral ischemia. Whether puerarin exhibits the same biological processes in neurons and astrocytes in vitro has rarely been reported. In this study, cortical neurons and astrocytes of newborn Sprague-Dawley rats were separated, identified and co-cultured in a system based on Transwell membranes. The retention time and distribution of puerarin in each cell type was detected by fluorescence spectrophotometry and fluorescence microscope. The concentration of puerarin in both co-cultured and separately cultured neurons was greater than that of astrocytes. Puerarin concentration reached a maximum 20 minutes after it was added. At 60 minutes after its addition, a scant amount of drug was detected in astrocytes; however in both separately cultured and co-cultured neurons, the concentration of puerarin achieved a stable level of about 12.8 ng/mL. The results indicate that puerarin had a higher concentration and longer retention time in neurons than that observed in astrocytes.
Kayama, Tasuku; Suzuki, Ikuro; Odawara, Aoi; Sasaki, Takuya; Ikegaya, Yuji
In culture conditions, human induced-pluripotent stem cells (hiPSC)-derived neurons form synaptic connections with other cells and establish neuronal networks, which are expected to be an in vitro model system for drug discovery screening and toxicity testing. While early studies demonstrated effects of co-culture of hiPSC-derived neurons with astroglial cells on survival and maturation of hiPSC-derived neurons, the population spiking patterns of such hiPSC-derived neurons have not been fully characterized. In this study, we analyzed temporal spiking patterns of hiPSC-derived neurons recorded by a multi-electrode array system. We discovered that specific sets of hiPSC-derived neurons co-cultured with astrocytes showed more frequent and highly coherent non-random synchronized spike trains and more dynamic changes in overall spike patterns over time. These temporally coordinated spiking patterns are physiological signs of organized circuits of hiPSC-derived neurons and suggest benefits of co-culture of hiPSC-derived neurons with astrocytes. Copyright © 2017 Elsevier Inc. All rights reserved.
Andreasen, Casper Schousboe; Gersborg, Allan Roulund; Sigmund, Ole
This paper demonstrates the application of the topology optimization method as a general and systematic approach for microfluidic mixer design. The mixing process is modeled as convection dominated transport in low Reynolds number incompressible flow. The mixer performance is maximized by altering...
The invention provides a microfluidic device for mixing liquid reagents, the device comprises, a chip forming at least one reaction chamber between a bottom and a top and extending between an inlet and an outlet. To enable manufacturing from less rigid materials, the device comprises pillars...
Gillies, J.M.; Prenant, C.; Chimon, G.N.; Smethurst, G.J.; Dekker, B.A.; Zweit, J.
This paper describes the first application of a microfabricated reaction system to positron emission tomography (PET) radiochemistry. We have applied microfluidic technology to synthesise PET radiopharmaceuticals using 18 F and 124 I as labels for fluorodeoxyglucose (FDG) and Annexin-V, respectively. These reactions involved established methods of nucleophilic substitution on a mannose triflate precursor and direct iodination of the protein using iodogen as an oxidant. This has demonstrated a proof of principle of using microfluidic technology to radiochemical reactions involving low and high molecular weight compounds. Using microfluidic reactions, [ 18 F]FDG was synthesised with a 50% incorporation of the available F-18 radioactivity in a very short time of 4 s. The radiolabelling efficiency of 124 I Annexin-V was 40% after 1 min reaction time. Chromatographic analysis showed that such reaction yields are comparable to conventional methods, but in a much shorter time. The yields can be further improved with more optimisation of the microfluidic device itself and its fluid mixing profiles. This demonstrates the potential for this technology to have an impact on rapid and simpler radiopharmaceutical synthesis using short and medium half-life radionuclides
Mcculloch, Quinn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
This report describes progress made on the microfluidic contactor. A model was developed to predict its failure, a surrogate chemical system was selected to demonstrate mass transfer, and an all-optical system has been invented and implemented to monitor carryover and flowrates.
Full Text Available Microfluidics is a multi-disciplinary field that deals with the behaviour, control and manipulation of fluids constrained to sub-millilitre volumes. It is proving to be a useful tool for biological studies, affording advantages such as reduced cost...
Hjorth, Poul G.; Deryabin, Mikhail
Mixing of fluids in microchannels cannot rely on turbulence since the flow takes place at extremly low Reynolds numbers. Various active and passive devices have been developed to induce mixing in microfluid flow devices. We describe here a model of an active mixer where a transverse periodic flow...
Ho, Tsung-Yi; Huang, Juinn-Dar; Pop, Paul
This tutorial will first provide an overview of typical bio-molecular applications (market drivers) such as immunoassays, DNA sequencing, clinical chemistry, etc. Next, microarrays and various microfluidic platforms will be discussed. The next part of the tutorial will focus on electro-wetting-ba......This tutorial will first provide an overview of typical bio-molecular applications (market drivers) such as immunoassays, DNA sequencing, clinical chemistry, etc. Next, microarrays and various microfluidic platforms will be discussed. The next part of the tutorial will focus on electro......-wetting-based digital micro-fluidic biochips. The key idea here is to manipulate liquids as discrete droplets. A number of case studies based on representative assays and laboratory procedures will be interspersed in appropriate places throughout the tutorial. Basic concepts in micro-fabrication techniques will also...... be discussed. Attendees will next learn about CAD and reconfiguration aspects of digital microfluidic biochips. Synthesis tools will be described to map assay protocols from the lab bench to a droplet-based microfluidic platform and generate an optimized schedule of bioassay operations, the binding of assay...
Edagawa, Akiko; Kimura, Akio; Kawabuchi-Kurata, Takako; Adachi, Shinichi; Furuhata, Katsunori; Miyamoto, Hiroshi
We investigated Legionella contamination in bath water samples, collected from 68 bathing facilities in Japan, by culture, culture with amoebic co-culture, real-time quantitative PCR (qPCR), and real-time qPCR with amoebic co-culture. Using the conventional culture method, Legionella pneumophila was detected in 11 samples (11/68, 16.2%). Contrary to our expectation, the culture method with the amoebic co-culture technique did not increase the detection rate of Legionella (4/68, 5.9%). In contrast, a combination of the amoebic co-culture technique followed by qPCR successfully increased the detection rate (57/68, 83.8%) compared with real-time qPCR alone (46/68, 67.6%). Using real-time qPCR after culture with amoebic co-culture, more than 10-fold higher bacterial numbers were observed in 30 samples (30/68, 44.1%) compared with the same samples without co-culture. On the other hand, higher bacterial numbers were not observed after propagation by amoebae in 32 samples (32/68, 47.1%). Legionella was not detected in the remaining six samples (6/68, 8.8%), irrespective of the method. These results suggest that application of the amoebic co-culture technique prior to real-time qPCR may be useful for the sensitive detection of Legionella from bath water samples. Furthermore, a combination of amoebic co-culture and real-time qPCR might be useful to detect viable and virulent Legionella because their ability to invade and multiply within free-living amoebae is considered to correlate with their pathogenicity for humans. This is the first report evaluating the efficacy of the amoebic co-culture technique for detecting Legionella in bath water samples.
Full Text Available We investigated Legionella contamination in bath water samples, collected from 68 bathing facilities in Japan, by culture, culture with amoebic co-culture, real-time quantitative PCR (qPCR, and real-time qPCR with amoebic co-culture. Using the conventional culture method, Legionella pneumophila was detected in 11 samples (11/68, 16.2%. Contrary to our expectation, the culture method with the amoebic co-culture technique did not increase the detection rate of Legionella (4/68, 5.9%. In contrast, a combination of the amoebic co-culture technique followed by qPCR successfully increased the detection rate (57/68, 83.8% compared with real-time qPCR alone (46/68, 67.6%. Using real-time qPCR after culture with amoebic co-culture, more than 10-fold higher bacterial numbers were observed in 30 samples (30/68, 44.1% compared with the same samples without co-culture. On the other hand, higher bacterial numbers were not observed after propagation by amoebae in 32 samples (32/68, 47.1%. Legionella was not detected in the remaining six samples (6/68, 8.8%, irrespective of the method. These results suggest that application of the amoebic co-culture technique prior to real-time qPCR may be useful for the sensitive detection of Legionella from bath water samples. Furthermore, a combination of amoebic co-culture and real-time qPCR might be useful to detect viable and virulent Legionella because their ability to invade and multiply within free-living amoebae is considered to correlate with their pathogenicity for humans. This is the first report evaluating the efficacy of the amoebic co-culture technique for detecting Legionella in bath water samples.
Lee, Seon-Bong; Kim, Ju-Hyeong; Cho, Myung-Haing; Choe, Eun-Sang; Kim, Kwang-Sik; Shim, Soon-Mi
The purpose of the current study was to investigate the effect of two commercial cigarette smoke condensates (CCSC) on oxidative stress and cell cytotoxicity in human brain (T98G) or astrocytes (U-373 MG) in the presence of human brain microvascular endothelial cells (HBMEC). Cell viability of mono-culture of T98G or U-373 MG was markedly decreased in a concentration-dependent manner, and T98G was more susceptible than U-373 MG to CCSC exposure. Cytotoxicity was less prominent when T98G was co-cultured with HBMEC than when T98G was co-cultured with U-373 MG. Significant reduction in trans-epithelial electric resistance (TEER), a biomarker of cellular integrity was noted in HBMEC co-cultured with T98G (HBMEC-T98G co-culture) and U-373 MG co-cultured with T98G (U-373 MG-T98G co-culture) after 24 or 48 hr CCSC exposure, respectively. TEER value of U-373 MG co-cultured with T98G (79-84%) was higher than HBMEC co-cultured with T98G (62-63%) within 120-hr incubation with CCSC. Reactive oxygen species (ROS) generated by CCSC in mono-culture of T98G and U-373 MG reached highest levels at 4 and 16 mg/ml, respectively. ROS production by T98G fell when co-cultured with HBMEC or U-373MG. These findings suggest that adverse consequences of CCSC treatment on brain cells may be protected by blood-brain barrier or astrocytes, but with chronic exposure toxicity may be worsened due to destruction of cellular integrity.
Full Text Available We report a robust magnetic-membrane-based microfluidic platform for controllable chemical release. The magnetic membrane was prepared by mixing polydimethylsiloxane (PDMS and carbonyl-iron nanoparticles together to obtain a flexible thin film. With combined, simultaneous regulation of magnetic stimulus and mechanical pumping, the desired chemical release rate can easily be realized. For example, the dose release experimental data was well fitted by a mathematical sigmoidal model, exhibiting a typical dose-response relationship, which shows promise in providing significant guidance for on-demand drug delivery. To test the platform’s feasibility, our microfluidic device was employed in an experiment involving Escherichia coli culture under controlled antibiotic ciprofloxacin exposure, and the expected outcomes were successfully obtained. Our experimental results indicate that such a microfluidic device, with high accuracy and easy manipulation properties, can legitimately be characterized as active chemical release system.
Lafleur, Josiane P.; Senkbeil, Silja; Jensen, Thomas G.
Conventional methods of environmental analysis can be significantly improved by the development of portable microscale technologies for direct in-field sensing at remote locations. This report demonstrates the vast potential of gold nanoparticle-based microfluidic sensors for the rapid, in......-field, detection of two important classes of environmental contaminants – heavy metals and pesticides. Using gold nanoparticle-based microfluidic sensors linked to a simple digital camera as the detector, detection limits as low as 0.6 μg L−1 and 16 μg L−1 could be obtained for the heavy metal mercury...... and the dithiocarbamate pesticide ziram, respectively. These results demonstrate that the attractive optical properties of gold nanoparticle probes combine synergistically with the inherent qualities of microfluidic platforms to offer simple, portable and sensitive sensors for environmental contaminants....
Pavuluri, S K; Lopez-Villarroya, R; McKeever, E; Goussetis, G; Desmulliez, M P Y; Kavanagh, D
A novel microfluidic sensing device based on waveguide cavity filters is proposed for the characterisation, detection of cells in solution and chemical substances in micro-litre volumes. The sensor consists of a micromachined microfluidic channel within a waveguide-based resonator localised increased near-fields and could potentially be designed for different frequency regimes to improve the sensitivity. The present sensor has been proposed for fabrication in different manufacturing platforms and an initial prototype with a 100μm micromachined channel that is embedded within an X-band E-plane waveguide has been fabricated and tested. The design methodology for the microfluidic channel and the E-plane filter is also presented.
Wang, Xiang; Li, Shunbo; Wang, Limu; Yi, Xin; Hui, Yu Sanna; Qin, Jianhua; Wen, Weijia
We report a robust magnetic-membrane-based microfluidic platform for controllable chemical release. The magnetic membrane was prepared by mixing polydimethylsiloxane (PDMS) and carbonyl-iron nanoparticles together to obtain a flexible thin film. With combined, simultaneous regulation of magnetic stimulus and mechanical pumping, the desired chemical release rate can easily be realized. For example, the dose release experimental data was well fitted by a mathematical sigmoidal model, exhibiting a typical dose-response relationship, which shows promise in providing significant guidance for on-demand drug delivery. To test the platform’s feasibility, our microfluidic device was employed in an experiment involving Escherichia coli culture under controlled antibiotic ciprofloxacin exposure, and the expected outcomes were successfully obtained. Our experimental results indicate that such a microfluidic device, with high accuracy and easy manipulation properties, can legitimately be characterized as active chemical release system.
Fernandes, Ana C.; Gernaey, Krist V.; Krühne, Ulrich
acceptance and more widespread use, are introduced. A brief review of the main materials and fabrication strategies used in these fields, is also presented. Finally, a step-wise guide towards the development of microfluidic systems is introduced with special focus on the integration of sensors...... of miniaturizing industrial production plants, thereby increasing their automation and operational safety at low cost; (2) being able to identify rare diseases by running bioanalytics directly on the patient’s skin; (3) allowing health diagnostics in point-of-care sites through cheap lab-on-a-chip devices. However...... and biotechnology fields, focusing mainly on the specialization on a single target of most microfluidic devices and offering a perspective on the alternate, multi-use, “plug and play” approach. Increasing the flexibility of microfluidic platforms, by increasing their compatibility with different substrates...
We report a robust magnetic-membrane-based microfluidic platform for controllable chemical release. The magnetic membrane was prepared by mixing polydimethylsiloxane (PDMS) and carbonyl-iron nanoparticles together to obtain a flexible thin film. With combined, simultaneous regulation of magnetic stimulus and mechanical pumping, the desired chemical release rate can easily be realized. For example, the dose release experimental data was well fitted by a mathematical sigmoidal model, exhibiting a typical dose-response relationship, which shows promise in providing significant guidance for on-demand drug delivery. To test the platform’s feasibility, our microfluidic device was employed in an experiment involving Escherichia coli culture under controlled antibiotic ciprofloxacin exposure, and the expected outcomes were successfully obtained. Our experimental results indicate that such a microfluidic device, with high accuracy and easy manipulation properties, can legitimately be characterized as active chemical release system.
Development of biocatalytic processes is greatly dominated by well-established batch process based screening technologies, e.g. glass vials (mL) and microtiter plates (μL). However, there is still a need for improvement of currently available technologies and for new technologies enabling...... relatively easy screening and characterization of different process options. For example, small-scale microfluidic platforms enable testing of complex process options, by combining multiple process steps in a plug-and-play manner, that are difficult to assess with conventional methods. Early...... of biocatalytic processes. Within this thesis, microfluidic modules are applied as tools to screen, characterize, and test reactor and separation process options. Furthermore, multiple microfluidic modules are combined in order to test complex process configurations, i.e. reactor modules combined with separation...
Goh, Bee See; Che Omar, Siti Nurhadis; Ubaidah, Muhammad Azhan; Saim, Lokman; Sulaiman, Shamsul; Chua, Kien Hui
In conclusion, these result showed HADSCs could differentiate into chondrocytes-like cells, dependent on signaling induced by TGF-β3 and chondrocytes. This is a promising result and showed that HADSCs is a potential source for future microtia repair. The technique of co-culture is a positive way forward to assist the microtia tissue. Reconstructive surgery for the repair of microtia still remains the greatest challenge among the surgeons. Its repair is associated with donor-site morbidity and the degree of infection is inevitable when using alloplastic prosthesis with uncertain long-term durability. Thus, human adipose derived stem cells (HADSCs) can be an alternative cell source for cartilage regeneration. This study aims to evaluate the chondrogenic potential of HADSCs cultured with transforming growth factor-beta (TGF-β) and interaction of auricular chondrocytes with HADSCs for new cartilage generation. Multi-lineages differentiation features of HADSCs were monitored by Alcian Blue, Alizarin Red, and Oil Red O staining for chondrogenic, adipogenic, and osteogenic differentiation capacity, respectively. Further, HADSCs alone were culture in medium added with TGF-β3; and human auricular chondrocytes were interacted indirectly in the culture with and without TGF-βs for up to 21 days, respectively. Cell morphology and chondrogenesis were monitored by inverted microscope. For cell viability, Alamar Blue assay was used to measure the cell viability and the changes in gene expression of auricular chondrocyte markers were determined by real-time polymerase chain reaction analysis. For the induction of chondrogenic differentiation, HADSCs showed a feature of aggregation and formed a dense matrix of proteoglycans. Staining results from Alizirin Red and Oil Red O indicated the HADSCs also successfully differentiated into adipogenic and osteogenic lineages after 21 days. According to a previous study, HADSCs were strongly positive for the mesenchymal markers CD90, CD73
Sadlonova, Andrea; Novak, Zdenek; Johnson, Martin R; Bowe, Damon B; Gault, Sandra R; Page, Grier P; Thottassery, Jaideep V; Welch, Danny R; Frost, Andra R
Stromal fibroblasts associated with in situ and invasive breast carcinoma differ phenotypically from fibroblasts associated with normal breast epithelium, and these alterations in carcinoma-associated fibroblasts (CAF) may promote breast carcinogenesis and cancer progression. A better understanding of the changes that occur in fibroblasts during carcinogenesis and their influence on epithelial cell growth and behavior could lead to novel strategies for the prevention and treatment of breast cancer. To this end, the effect of CAF and normal breast-associated fibroblasts (NAF) on the growth of epithelial cells representative of pre-neoplastic breast disease was assessed. NAF and CAF were grown with the nontumorigenic MCF10A epithelial cells and their more transformed, tumorigenic derivative, MCF10AT cells, in direct three-dimensional co-cultures on basement membrane material. The proliferation and apoptosis of MCF10A cells and MCF10AT cells were assessed by 5-bromo-2'-deoxyuridine labeling and TUNEL assay, respectively. Additionally, NAF and CAF were compared for expression of insulin-like growth factor II as a potential mediator of their effects on epithelial cell growth, by ELISA and by quantitative, real-time PCR. In relatively low numbers, both NAF and CAF suppressed proliferation of MCF10A cells. However, only NAF and not CAF significantly inhibited proliferation of the more transformed MCF10AT cells. The degree of growth inhibition varied among NAF or CAF from different individuals. In greater numbers, NAF and CAF have less inhibitory effect on epithelial cell growth. The rate of epithelial cell apoptosis was not affected by NAF or CAF. Mean insulin-like growth factor II levels were not significantly different in NAF versus CAF and did not correlate with the fibroblast effect on epithelial cell proliferation. Both NAF and CAF have the ability to inhibit the growth of pre-cancerous breast epithelial cells. NAF have greater inhibitory capacity than CAF
Jones, Erin Boote [Iowa State Univ., Ames, IA (United States)
In recent years the study of stem and progenitor cells has moved to the forefront of research. Since the isolation of human hematopoietic stem cells in 1988 and the subsequent discovery of a self renewing population of multipotent cells in many tissues, many researchers have envisioned a better understanding of development and potential clinical usage in intractable diseases. Both these goals, however, depend on a solid understanding of the intracellular and extracellular forces that cause stem cells to differentiate to a specific cell fate. Many diseases of large scale cell loss have been suggested as candidates for stem cell based treatments. It is proposed that replacing the function of the damaged or defective cells by specific differentiation of stem or progenitor cells could treat the disease. Before cells can be directed to specific lineages, the mechanisms of differentiation must be better understood. Differentiation in vivo is an intensively complex system that is difficult to study. The goal of this research is to develop further understanding of the effects of soluble and extracellular matrix (ECM) cues on the differentiation of neural progenitor cells with the use of a simplified in vitro culture system. Specific research objectives are to study the differentiation of neural progenitor cells in response to astrocyte conditioned medium and protein substrate composition and concentration. In an effort to reveal the mechanism of the conditioned medium interaction, a test for the presence of a feedback loop between progenitor cells and astrocytes is presented along with an examination of conditioned medium storage temperature, which can reveal enzymatic dependencies. An examination of protein substrate composition and concentration will help to reveal the role of any ECM interactions on differentiation. This thesis is organized into a literature review covering recent advances in use of external modulators of differentiation such as surface coatings, co-culture
Full Text Available BACKGROUND: The development of clean or novel alternative energy has become a global trend that will shape the future of energy. In the present study, 3 microbial strains with different oxygen requirements, including Clostridium acetobutylicum ATCC 824, Enterobacter cloacae ATCC 13047 and Kluyveromyces marxianus 15D, were used to construct a hydrogen production system that was composed of a mixed aerobic-facultative anaerobic-anaerobic consortium. The effects of metal ions, organic acids and carbohydrate substrates on this system were analyzed and compared using electrochemical and kinetic assays. It was then tested using small-scale experiments to evaluate its ability to convert starch in 5 L of organic wastewater into hydrogen. For the one-step biohydrogen production experiment, H1 medium (nutrient broth and potato dextrose broth was mixed directly with GAM broth to generate H2 medium (H1 medium and GAM broth. Finally, Clostridium acetobutylicum ATCC 824, Enterobacter cloacae ATCC 13047 and Kluyveromyces marxianus 15D of three species microbial co-culture to produce hydrogen under anaerobic conditions. For the two-step biohydrogen production experiment, the H1 medium, after cultured the microbial strains Enterobacter cloacae ATCC 13047 and Kluyveromyces marxianus 15D, was centrifuged to remove the microbial cells and then mixed with GAM broth (H2 medium. Afterward, the bacterial strain Clostridium acetobutylicum ATCC 824 was inoculated into the H2 medium to produce hydrogen by anaerobic fermentation. RESULTS: The experimental results demonstrated that the optimum conditions for the small-scale fermentative hydrogen production system were at pH 7.0, 35°C, a mixed medium, including H1 medium and H2 medium with 0.50 mol/L ferrous chloride, 0.50 mol/L magnesium sulfate, 0.50 mol/L potassium chloride, 1% w/v citric acid, 5% w/v fructose and 5% w/v glucose. The overall hydrogen production efficiency in the shake flask fermentation group was 33.7 m
Full Text Available Background: Even though epidermal growth factor-like domain 7 is known to be overexpressed in osteosarcoma and is associated with poor clinical outcome, few reports are available regarding its mechanism. Aims: The objective of this study was to explore the effect and mechanism of downregulating epidermal growth factor-like domain 7 expression in a human osteosarcoma cell line on the biological function of co-cultured human umbilical vein endothelial cells. Study Design: Cell study. Methods: In the present study, human osteosarcoma cell lines U2OS, Saos-2, HOS, and MG63, and normal human osteoblasts were cultured in Dulbecco’s Modified Eagle Medium containing 10% fetal bovine serum and 1x antibiotics at 37 °C and 5% CO2 in an incubator. Of the four osteosarcoma cell lines, U2OS expresses the highest level of epidermal growth factor-like domain 7 mRNA as determined using quantitative reverse transcription polymerase chain reaction. With the knockdown of epidermal growth factor-like domain 7 in U2OS and human umbilical vein endothelial cells by lentivirus, the proliferation and apoptosis of U2OS and human umbilical vein endothelial cells were investigated using MTT and flow cytometry assays. After the co-culture of human umbilical vein endothelial cells and epidermal growth factor-like domain 7-knockdown U2OS, the in vitro effects on cell proliferation, apoptosis, adhesion, migration, and the angiogenic ability of human umbilical vein endothelial cells were detected using MTT, flow cytometry, Transwell, and tube formation assays, respectively. The expressions of phosphoinositide 3-kinase, phospho-Akt, total Akt, and vascular endothelial growth factor in human umbilical vein endothelial cells were detected using western blot assay. Results: Lentivirus with epidermal growth factor-like domain 7 shRNA could not significantly affect the proliferation and apoptosis of both U2OS and human umbilical vein endothelial cells, whereas the knockdown of
Hastanin, J.; Lenaerts, C.; Gailly, P.; Jans, H.; Huang, C.; Lagae, L.; Kokkinos, D.; Fleury-Frenette, K.
In this paper, we present an original concept of plasmonic-related instrumentation platform dedicated to diagnostic biosensing tests out of the laboratory. The developed instrumental platform includes both disposable one-use microfluidic affinity biochip and compact optical readout device for biochip monitoring involving mobile Internet devices for data processing and communication. The biochip includes both microfluidic and optical coupling structures formed into a single plastic slab. The microfluidic path of the biochip operates in passive capillary pumping mode. In the proof-of-concept prototype, we address specifically the sensing format involving Surface Plasmon Resonance phenomenon. The biochip is plugged in the readout device without the use of an index matching fluid. An essential advantage of the developed biochip is that its implementation involves conventional hot embossing and thin film deposition process, perfectly suited for mass production of low-cost microfluidic biochip for biochemical applications.
Berenguel-Alonso, Miguel; Sabés-Alsina, Maria; Morató, Roser; Ymbern, Oriol; Rodríguez-Vázquez, Laura; Talló-Parra, Oriol; Alonso-Chamarro, Julián; Puyol, Mar; López-Béjar, Manel
Assisted reproductive technology (ART) can benefit from the features of microfluidic technologies, such as the automation of time-consuming labor-intensive procedures, the possibility to mimic in vivo environments, and the miniaturization of the required equipment. To date, most of the proposed approaches are based on polydimethylsiloxane (PDMS) as platform substrate material due to its widespread use in academia, despite certain disadvantages, such as the elevated cost of mass production. Herein, we present a rapid fabrication process for a cyclic olefin copolymer (COC) monolithic microfluidic device combining hot embossing-using a low-temperature cofired ceramic (LTCC) master-and micromilling. The microfluidic device was suitable for trapping and maturation of bovine oocytes, which were further studied to determine their ability to be fertilized. Furthermore, another COC microfluidic device was fabricated to store sperm and assess its quality parameters over time. The study herein presented demonstrates a good biocompatibility of the COC when working with gametes, and it exhibits certain advantages, such as the nonabsorption of small molecules, gas impermeability, and low fabrication costs, all at the prototyping and mass production scale, thus taking a step further toward fully automated microfluidic devices in ART.
Full Text Available We review the utility of centrifugal microfluidic technologies applied to point-of-care diagnosis in extremely under-resourced environments. The various challenges faced in these settings are showcased, using areas in India and Africa as examples. Measures for the ability of integrated devices to effectively address point-of-care challenges are highlighted, and centrifugal, often termed CD-based microfluidic technologies, technologies are presented as a promising platform to address these challenges. We describe the advantages of centrifugal liquid handling, as well as the ability of a standard CD player to perform a number of common laboratory tests, fulfilling the role of an integrated lab-on-a-CD. Innovative centrifugal approaches for point-of-care in extremely resource-poor settings are highlighted, including sensing and detection strategies, smart power sources and biomimetic inspiration for environmental control. The evolution of centrifugal microfluidics, along with examples of commercial and advanced prototype centrifugal microfluidic systems, is presented, illustrating the success of deployment at the point-of-care. A close fit of emerging centrifugal systems to address a critical panel of tests for under-resourced clinic settings, formulated by medical experts, is demonstrated. This emphasizes the potential of centrifugal microfluidic technologies to be applied effectively to extremely challenging point-of-care scenarios and in playing a role in improving primary care in resource-limited settings across the developing world.
Hosseini, Samira; Aeinehvand, Mohammad M; Uddin, Shah M; Benzina, Abderazak; Rothan, Hussin A; Yusof, Rohana; Koole, Leo H; Madou, Marc J; Djordjevic, Ivan; Ibrahim, Fatimah
The application of microfluidic devices in diagnostic systems is well-established in contemporary research. Large specific surface area of microspheres, on the other hand, has secured an important position for their use in bioanalytical assays. Herein, we report a combination of microspheres and microfluidic disk in a unique hybrid platform for highly sensitive and selective detection of dengue virus. Surface engineered polymethacrylate microspheres with carefully designed functional groups facilitate biorecognition in a multitude manner. In order to maximize the utility of the microspheres' specific surface area in biomolecular interaction, the microfluidic disk was equipped with a micromixing system. The mixing mechanism (microballoon mixing) enhances the number of molecular encounters between spheres and target analyte by accessing the entire sample volume more effectively, which subsequently results in signal amplification. Significant reduction of incubation time along with considerable lower detection limits were the prime motivations for the integration of microspheres inside the microfluidic disk. Lengthy incubations of routine analytical assays were reduced from 2 hours to 5 minutes while developed system successfully detected a few units of dengue virus. Obtained results make this hybrid microsphere-microfluidic approach to dengue detection a promising avenue for early detection of this fatal illness.
Lyubimov, Artem Y. [Stanford University, Stanford, CA 94305 (United States); Stanford University, Stanford, CA 94305 (United States); Stanford University, Stanford, CA 94305 (United States); Stanford University, Stanford, CA 94305 (United States); Stanford University, Stanford, CA 94305 (United States); Murray, Thomas D. [University of California, Berkeley, CA 94720 (United States); Johns Hopkins University School of Medicine, Baltimore, MD 21205 (United States); Koehl, Antoine [Stanford University, Stanford, CA 94305 (United States); Araci, Ismail Emre [Stanford University, Stanford, CA 94305 (United States); Stanford University, Stanford, CA 94305 (United States); Uervirojnangkoorn, Monarin; Zeldin, Oliver B. [Stanford University, Stanford, CA 94305 (United States); Stanford University, Stanford, CA 94305 (United States); Stanford University, Stanford, CA 94305 (United States); Stanford University, Stanford, CA 94305 (United States); Stanford University, Stanford, CA 94305 (United States); Cohen, Aina E.; Soltis, S. Michael; Baxter, Elizabeth L. [SLAC National Accelerator Laboratory, Stanford, CA 94305 (United States); Brewster, Aaron S.; Sauter, Nicholas K. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Brunger, Axel T., E-mail: email@example.com [Stanford University, Stanford, CA 94305 (United States); Stanford University, Stanford, CA 94305 (United States); Stanford University, Stanford, CA 94305 (United States); Stanford University, Stanford, CA 94305 (United States); Stanford University, Stanford, CA 94305 (United States); Berger, James M., E-mail: firstname.lastname@example.org [Johns Hopkins University School of Medicine, Baltimore, MD 21205 (United States); Stanford University, Stanford, CA 94305 (United States)
A microfluidic platform has been developed for the capture and X-ray analysis of protein microcrystals, affording a means to improve the efficiency of XFEL and synchrotron experiments. X-ray free-electron lasers (XFELs) promise to enable the collection of interpretable diffraction data from samples that are refractory to data collection at synchrotron sources. At present, however, more efficient sample-delivery methods that minimize the consumption of microcrystalline material are needed to allow the application of XFEL sources to a wide range of challenging structural targets of biological importance. Here, a microfluidic chip is presented in which microcrystals can be captured at fixed, addressable points in a trap array from a small volume (<10 µl) of a pre-existing slurry grown off-chip. The device can be mounted on a standard goniostat for conducting diffraction experiments at room temperature without the need for flash-cooling. Proof-of-principle tests with a model system (hen egg-white lysozyme) demonstrated the high efficiency of the microfluidic approach for crystal harvesting, permitting the collection of sufficient data from only 265 single-crystal still images to permit determination and refinement of the structure of the protein. This work shows that microfluidic capture devices can be readily used to facilitate data collection from protein microcrystals grown in traditional laboratory formats, enabling analysis when cryopreservation is problematic or when only small numbers of crystals are available. Such microfluidic capture devices may also be useful for data collection at synchrotron sources.
Kong, Xianming; Chong, Xinyuan; Squire, Kenny; Wang, Alan X
The escalating research interests in porous media microfluidics, such as microfluidic paper-based analytical devices, have fostered a new spectrum of biomedical devices for point-of-care (POC) diagnosis and biosensing. In this paper, we report microfluidic diatomite analytical devices (μDADs), which consist of highly porous photonic crystal biosilica channels, as an innovative lab-on-a-chip platform to detect illicit drugs. The μDADs in this work are fabricated by spin-coating and tape-stripping diatomaceous earth on regular glass slides with cross section of 400×30µm 2 . As the most unique feature, our μDADs can simultaneously perform on-chip chromatography to separate small molecules from complex biofluidic samples and acquire the surface-enhanced Raman scattering spectra of the target chemicals with high specificity. Owing to the ultra-small dimension of the diatomite microfluidic channels and the photonic crystal effect from the fossilized diatom frustules, we demonstrate unprecedented sensitivity down to part-per-billion (ppb) level when detecting pyrene (1ppb) from mixed sample with Raman dye and cocaine (10 ppb) from human plasma. This pioneering work proves the exclusive advantage of μDADs as emerging microfluidic devices for chemical and biomedical sensing, especially for POC drug screening.
Yuan, Huiling; Dong, Libing; Tu, Ran; Du, Wenbin; Ji, Shiru; Wang, Qinhong
Recently, the droplet microfluidic system attracts interests due to its high throughput and low cost to detect and screen. The picoliter micro-droplets from droplet microfluidics are uniform with respect to the size and shape, and could be used as monodispensed micro-reactors for encapsulation and detection of single cell or its metabolites. Therefore, it is indispensable to characterize micro-droplet and its application from droplet microfluidic system. We first constructed the custom-designed droplet microfluidic system for generating micro-droplets, and then used the micro-droplets to encapsulate important amino acids such as glutamic acid, phenylalanine, tryptophan or tyrosine to test the droplets' properties, including the stability, diffusivity and bio-compatibility for investigating its application for amino acid detection and sorting. The custom-designed droplet microfluidic system could generate the uniformed micro-droplets with a controllable size between 20 to 50 microm. The micro-droplets could be stable for more than 20 h without cross-contamination or fusion each other. The throughput of detection and sorting of the system is about 600 micro-droplets per minute. This study provides a high-throughput platform for the analysis and screening of amino acid-producing microorganisms.
Frey, Olivier; Misun, Patrick M; Fluri, David A; Hengstler, Jan G; Hierlemann, Andreas
Integration of multiple three-dimensional microtissues into microfluidic networks enables new insights in how different organs or tissues of an organism interact. Here, we present a platform that extends the hanging-drop technology, used for multi-cellular spheroid formation, to multifunctional complex microfluidic networks. Engineered as completely open, 'hanging' microfluidic system at the bottom of a substrate, the platform features high flexibility in microtissue arrangements and interconnections, while fabrication is simple and operation robust. Multiple spheroids of different cell types are formed in parallel on the same platform; the different tissues are then connected in physiological order for multi-tissue experiments through reconfiguration of the fluidic network. Liquid flow is precisely controlled through the hanging drops, which enable nutrient supply, substance dosage and inter-organ metabolic communication. The possibility to perform parallelized microtissue formation on the same chip that is subsequently used for complex multi-tissue experiments renders the developed platform a promising technology for 'body-on-a-chip'-related research.
Matschuk, Maria; Bruus, Henrik; Larsen, Niels Bent
antistiction coating was found to improve the replication fidelity (shape and depth) of nanoscale features substantially. Arrays of holes of 50 nm diameter/35 nm depth and 100 nm/100 nm diameter, respectively, were mass-produced in cyclic olefin copolymer (Topas 5013) by injection molding. Polymer microfluidic...... channel chip parts resulted from a separate injection molding process. The microfluidic chip part and the nanostructured chip part were successfully bonded to form a sealed microfluidic system using air plasma assisted thermal bonding....
Luka, George; Ahmadi, Ali; Najjaran, Homayoun; Alocilja, Evangelyn; DeRosa, Maria; Wolthers, Kirsten; Malki, Ahmed; Aziz, Hassan; Althani, Asmaa; Hoorfar, Mina
A biosensor can be defined as a compact analytical device or unit incorporating a biological or biologically derived sensitive recognition element immobilized on a physicochemical transducer to measure one or more analytes. Microfluidic systems, on the other hand, provide throughput processing, enhance transport for controlling the flow conditions, increase the mixing rate of different reagents, reduce sample and reagents volume (down to nanoliter), increase sensitivity of detection, and utilize the same platform for both sample preparation and detection. In view of these advantages, the integration of microfluidic and biosensor technologies provides the ability to merge chemical and biological components into a single platform and offers new opportunities for future biosensing applications including portability, disposability, real-time detection, unprecedented accuracies, and simultaneous analysis of different analytes in a single device. This review aims at representing advances and achievements in the field of microfluidic-based biosensing. The review also presents examples extracted from the literature to demonstrate the advantages of merging microfluidic and biosensing technologies and illustrate the versatility that such integration promises in the future biosensing for emerging areas of biological engineering, biomedical studies, point-of-care diagnostics, environmental monitoring, and precision agriculture. PMID:26633409
Butement, Jonathan T; Rowe, David J; Sessions, Neil P; Hua, Ping; Murugan, G Senthil; Wilkinson, James S; Clark, Owain; Chad, John E; Hunt, Hamish C
A key challenge in the development of a microflow cytometry platform is the integration of the optical components with the fluidics as this requires compatible micro-optical and microfluidic technologies. In this work a microflow cytometry platform is presented comprising monolithically integrated waveguides and deep microfluidics in a rugged silica chip. Integrated waveguides are used to deliver excitation light to an etched microfluidic channel and also collect transmitted light. The fluidics are designed to employ inertial focussing, a particle positioning technique, to reduce signal variation by bringing the flowing particles onto the same plane as the excitation light beam. A fabrication process is described which exploits microelectronics mass production techniques including: sputtering, ICP etching and PECVD. Example devices were fabricated and the effectiveness of inertial focussing of 5.6 µ m fluorescent beads was studied showing lateral and vertical confinement of flowing beads within the microfluidic channel. The fluorescence signals from flowing calibration beads were quantified demonstrating a CV of 26%. Finally the potential of this type of device for measuring the variation in optical transmission from input to output waveguide as beads flowed through the beam was evaluated. (paper)
Full Text Available A biosensor can be defined as a compact analytical device or unit incorporating a biological or biologically derived sensitive recognition element immobilized on a physicochemical transducer to measure one or more analytes. Microfluidic systems, on the other hand, provide throughput processing, enhance transport for controlling the flow conditions, increase the mixing rate of different reagents, reduce sample and reagents volume (down to nanoliter, increase sensitivity of detection, and utilize the same platform for both sample preparation and detection. In view of these advantages, the integration of microfluidic and biosensor technologies provides the ability to merge chemical and biological components into a single platform and offers new opportunities for future biosensing applications including portability, disposability, real-time detection, unprecedented accuracies, and simultaneous analysis of different analytes in a single device. This review aims at representing advances and achievements in the field of microfluidic-based biosensing. The review also presents examples extracted from the literature to demonstrate the advantages of merging microfluidic and biosensing technologies and illustrate the versatility that such integration promises in the future biosensing for emerging areas of biological engineering, biomedical studies, point-of-care diagnostics, environmental monitoring, and precision agriculture.
Tran, Reginald; Myers, David R; Denning, Gabriela; Shields, Jordan E; Lytle, Allison M; Alrowais, Hommood; Qiu, Yongzhi; Sakurai, Yumiko; Li, William C; Brand, Oliver; Le Doux, Joseph M; Spencer, H Trent; Doering, Christopher B; Lam, Wilbur A
Ex vivo gene therapy using lentiviral vectors (LVs) is a proven approach to treat and potentially cure many hematologic disorders and malignancies but remains stymied by cumbersome, cost-prohibitive, and scale-limited production processes that cannot meet the demands of current clinical protocols for widespread clinical utilization. However, limitations in LV manufacture coupled with inefficient transduction protocols requiring significant excess amounts of vector currently limit widespread implementation. Herein, we describe a microfluidic, mass transport-based approach that overcomes the diffusion limitations of current transduction platforms to enhance LV gene transfer kinetics and efficiency. This novel ex vivo LV transduction platform is flexible in design, easy to use, scalable, and compatible with standard cell transduction reagents and LV preparations. Using hematopoietic cell lines, primary human T cells, primary hematopoietic stem and progenitor cells (HSPCs) of both murine (Sca-1 + ) and human (CD34 + ) origin, microfluidic transduction using clinically processed LVs occurs up to 5-fold faster and requires as little as one-twentieth of LV. As an in vivo validation of the microfluidic-based transduction technology, HSPC gene therapy was performed in hemophilia A mice using limiting amounts of LV. Compared to the standard static well-based transduction protocols, only animals transplanted with microfluidic-transduced cells displayed clotting levels restored to normal. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.
Wang, Tanyu; Zhang, Mohan; Dreher, Dakota D; Zeng, Yong
Quantitative detection of low abundance proteins is of significant interest for biological and clinical applications. Here we report an integrated microfluidic solid-phase ELISA platform for rapid and ultrasensitive detection of proteins with a wide dynamic range. Compared to the existing microfluidic devices that perform affinity capture and enzyme-based optical detection in a constant channel volume, the key novelty of our design is two-fold. First, our system integrates a microwell-patterned assay chamber that can be pneumatically actuated to significantly reduce the volume of chemifluorescent reaction, markedly improving the sensitivity and speed of ELISA. Second, monolithic integration of on-chip pumps and the actuatable assay chamber allow programmable fluid delivery and effective mixing for rapid and sensitive immunoassays. Ultrasensitive microfluidic ELISA was demonstrated for insulin-like growth factor 1 receptor (IGF-1R) across at least five orders of magnitude with an extremely low detection limit of 21.8 aM. The microwell-based solid-phase ELISA strategy provides an expandable platform for developing the next-generation microfluidic immunoassay systems that integrate and automate digital and analog measurements to further improve the sensitivity, dynamic ranges, and reproducibility of proteomic analysis.
Inglis, David W.; Riehn, Robert; Sturm, James C.; Austin, Robert H.
Separation of blood cells by native susceptibility and by the selective attachment of magnetic beads has recently been demonstrated on microfluidic devices. We discuss the basic principles of how forces are generated via the magnetic susceptibility of an object and how microfluidics can be combined with micron-scale magnetic field gradients to greatly enhance in principle the fractionating power of magnetic fields. We discuss our efforts and those of others to build practical microfluidic devices for the magnetic separation of blood cells. We also discuss our attempts to integrate magnetic separation with other microfluidic features for developing handheld medical diagnostic tools.
This paper reports a new method for integrating microlenses into microfluidic devices for improved observation. Two demonstration microfluidic devices were provided which were fabricated using this new technique. The integrated microlenses were fabricated using a free-surface thermo-compression molding method on a polystyrene (PS) sheet which was then bonded on top of microfluidic channels as a cover plate, with the convex microlenses providing a magnified image of the channel for the easier observation of the flow in the microchannels. This approach for fabricating the integrated microlens in microfluidic devices is rapid, low cost and without the requirement of cleanroom facilities. © 2013 IEEE.
Pilát, Zdeněk.; Ježek, Jan; Šmatlo, Filip; Kaůka, Jan; Zemánek, Pavel
Enzymes are highly versatile and ubiquitous biological catalysts. They can greatly accelerate large variety of reactions, while ensuring appropriate catalytic activity and high selectivity. These properties make enzymes attractive biocatalysts for a wide range of industrial and biomedical applications. Over the last two decades, directed evolution of enzymes has transformed the field of protein engineering. We have devised microfluidic systems for directed evolution of haloalkane dehalogenases in emulsion droplets. In such a device, individual bacterial cells producing mutated variants of the same enzyme are encapsulated in microdroplets and supplied with a substrate. The conversion of a substrate by the enzyme produced by a single bacterium changes the pH in the droplet which is signalized by pH dependent fluorescence probe. The droplets with the highest enzymatic activity can be separated directly on the chip by dielectrophoresis and the resultant cell lineage can be used for enzyme production or for further rounds of directed evolution. This platform is applicable for fast screening of large libraries in directed evolution experiments requiring mutagenesis at multiple sites of a protein structure.
Kidambi, Srivatsan; Lee, Ilsoon; Chan, Christina
We engineered patterned co-cultures of primary neurons and astrocytes on polyelectrolyte multilayer (PEM) films without the aid of adhesive proteins/ligands to study the oxidative stress mediated by astrocytes on neuronal cells. A number of studies have explored engineering co-culture of neurons and astrocytes predominantly using cell lines rather than primary cells owing to the difficulties involved in attaching primary cells onto synthetic surfaces. To our knowledge this is the first demons...
Ghanavati, Zeinab; Orazizadeh, Mahmoud; Bayati, Vahid; Abbaspour, Mohammad Reza; Khorsandi, Layasadat; Mansouri, Esrafil; Neisi, Niloofar
The organotypic co-culture is a well-known technique to examine cellular interactions and their roles in stem cell proliferation and differentiation. This study aims to evaluate the effects of dermal fibroblasts (DFs) on epidermal differentiation of adipose-derived stem cells (ASCs) using a three-dimensional (3D) organotypic co- culture technique. In this experimental research study, rat DFs and ASCs were isolated and cultured separately on electrospun polycaprolactone (PCL) matrices. The PCL matrices seeded by ASCs were superimposed on to the matrices seeded by DFs in order to create a 3D organotypic co-culture. In the control groups, PCL matrices seeded by ASCs were placed on matrices devoid of DFs. After 10 days, we assessed the expressions of keratinocyte-related genes by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and expression of pan-cytokeratin protein by immunofluorescence in the differentiated keratinocyte-like cells from co- culture and control groups. Keratinocyte-like cell morphologies were also observed by scanning electron microscopy (SEM). The early, intermediate, and terminal differentiation keratinocyte markers-Cytokeratin14, Filaggrin, and Involucrin significantly expressed in the co-culture groups com- pared to the control ones (P<0.05). We observed pan-cytokeratin in keratinocyte-like cells of both groups by immunofluorescence. SEM observation of the co-culture groups showed that the differentiated keratinocyte-like cells developed a polygonal cobblestone shape, considered characteristic of keratinocytes. The 3D organotypic co-culture bilayered construct that consisted of DFs and ASCs was an effective technique for epidermal differentiation of ASCs. This co-culture might be useful for epidermal differentiation of stem cells for future applications in skin regeneration.
Full Text Available Abstract Background Butein (3,4,2',4'-tetrahydroxychalone, a plant polyphenol, is a major biologically active component of the stems of Rhus verniciflua Stokes. It has long been used as a food additive in Korea and as an herbal medicine throughout Asia. Recently, butein has been shown to suppress the functions of fibroblasts. Because fibroblasts are believed to play an important role in promoting the growth of breast cancer cells, we investigated the ability of butein to inhibit the clonogenic growth of small numbers of breast cancer cells co-cultured with fibroblasts in vitro. Methods We first measured the clonogenic growth of small numbers of the UACC-812 human breast cancer cell line co-cultured on monolayers of serum-activated, human fibroblasts in the presence of butein (2 μg/mL or various other modulators of fibroblast function (troglitazone-1 μg/mL; GW9662-1 μM; meloxican-1 μM; and 3,4 dehydroproline-10 μg/mL. In a subsequent experiment, we measured the dose-response effect on the clonogenic growth of UACC-812 breast cancer cells by pre-incubating the fibroblasts with varying concentrations of butein (10 μg/ml-1.25 μg/mL. Finally, we measured the clonogenic growth of primary breast cancer cells obtained from 5 clinical specimens with normal fibroblasts and with fibroblasts that had been pre-treated with a fixed dose of butein (2.5 μg/mL. Results Of the five modulators of fibroblast function that we tested, butein was by far the most potent inhibitor of clonogenic growth of UACC-812 breast cancer cells co-cultured with fibroblasts. Pre-treatment of fibroblasts with concentrations of butein as low as 2.5 μg/mL nearly abolished subsequent clonogenic growth of UACC-812 breast cancer cells co-cultured with the fibroblasts. A similar dose of butein had no effect on the clonogenic growth of breast cancer cells cultured in the absence of fibroblasts. Significantly, clonogenic growth of the primary breast cancer cells was also
Skottman, H; Muranen, J; Lähdekorpi, H; Pajula, E; Mäkelä, K; Koivusalo, L; Koistinen, A; Uusitalo, H; Kaarniranta, K; Juuti-Uusitalo, K
Here we evaluated the effects of human retinal microvascular endothelial cells (hREC) on mature human embryonic stem cell (hESC) derived retinal pigment epithelial (RPE) cells. The hESC-RPE cells (Regea08/017, Regea08/023 or Regea11/013) and hREC (ACBRI 181) were co-cultured on opposite sides of transparent membranes for up to six weeks. Thereafter barrier function, small molecule permeability, localization of RPE and endothelial cell marker proteins, cellular fine structure, and growth factor secretion of were evaluated. After co-culture, the RPE specific CRALBP and endothelial cell specific von Willebrand factor were appropriately localized. In addition, the general morphology, pigmentation, and fine structure of hESC-RPE cells were unaffected. Co-culture increased the barrier function of hESC-RPE cells, detected both with TEER measurements and cumulative permeability of FD4 - although the differences varied among the cell lines. Co-culturing significantly altered VEGF and PEDF secretion, but again the differences were cell line specific. The results of this study showed that co-culture with hREC affects hESC-RPE functionality. In addition, co-culture revealed drastic cell line specific differences, most notably in growth factor secretion. This model has the potential to be used as an in vitro outer blood-retinal barrier model for drug permeability testing. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.
Deng, Yuan; Jiang, Chuan; Li, Cuidi; Li, Tao; Peng, Mingzheng; Wang, Jinwu; Dai, Kerong
Synthetic bone scaffolds have potential application in repairing large bone defects, however, inefficient vascularization after implantation remains the major issue of graft failure. Herein, porous β-tricalcium phosphate (β-TCP) scaffolds with calcium silicate (CS) were 3D printed, and pre-seeded with co-cultured human umbilical cord vein endothelial cells (HUVECs) and human bone marrow stromal cells (hBMSCs) to construct tissue engineering scaffolds with accelerated vascularization and better bone formation. Results showed that in vitro β-TCP scaffolds doped with 5% CS (5%CS/β-TCP) were biocompatible, and stimulated angiogenesis and osteogenesis. The results also showed that 5%CS/β-TCP scaffolds not only stimulated co-cultured cells angiogenesis on Matrigel, but also stimulated co-cultured cells to form microcapillary-like structures on scaffolds, and promoted migration of BMSCs by stimulating co-cultured cells to secrete PDGF-BB and CXCL12 into the surrounding environment. Moreover, 5%CS/β-TCP scaffolds enhanced vascularization and osteoinduction in comparison with β-TCP, and synergized with co-cultured cells to further increase early vessel formation, which was accompanied by earlier and better ectopic bone formation when implanted subcutaneously in nude mice. Thus, our findings suggest that porous 5%CS/β-TCP scaffolds seeded with co-cultured cells provide new strategy for accelerating tissue engineering scaffolds vascularization and osteogenesis, and show potential as treatment for large bone defects.
Samoszuk, Michael; Tan, Jenny; Chorn, Guillaume
Accumulating evidence suggests that fibroblasts play a pivotal role in promoting the growth of breast cancer cells. The objective of the present study was to characterize and validate an in vitro model of the interaction between small numbers of human breast cancer cells and human fibroblasts. We measured the clonogenic growth of small numbers of human breast cancer cells co-cultured in direct contact with serum-activated, normal human fibroblasts. Using DNA microarrays, we also characterized the gene expression profile of the serum-activated fibroblasts. In order to validate the in vivo relevance of our experiments, we then analyzed clinical samples of metastatic breast cancer for the presence of myofibroblasts expressing α-smooth muscle actin. Clonogenic growth of human breast cancer cells obtained directly from in situ and invasive tumors was dramatically and consistently enhanced when the tumor cells were co-cultured in direct contact with serum-activated fibroblasts. This effect was abolished when the cells were co-cultured in transwells separated by permeable inserts. The fibroblasts in our experimental model exhibited a gene expression signature characteristic of 'serum response' (i.e. myofibroblasts). Immunostaining of human samples of metastatic breast cancer tissue confirmed that myofibroblasts are in direct contact with breast cancer cells. Serum-activated fibroblasts promote the clonogenic growth of human breast cancer cells in vitro through a mechanism that involves direct physical contact between the cells. This model shares many important molecular and phenotypic similarities with the fibroblasts that are naturally found in breast cancers
Bridget S Fisher
Full Text Available Globally, there are greater than 700,000 deaths per year associated with diarrheal disease. The flagellated intestinal parasite, Giardia lamblia, is one of the most common intestinal pathogens in both humans and animals throughout the world. While attached to the gastrointestinal epithelium, Giardia induces epithelial cell apoptosis, disrupts tight junctions, and increases intestinal permeability. The underlying cellular and molecular mechanisms of giardiasis, including the role lamina propria immune cells, such as macrophages, play in parasite control or clearance are poorly understood. Thus far, one of the major obstacles in ascertaining the mechanisms of Giardia pathology is the lack of a functionally relevant model for the long-term study of the parasite in vitro. Here we report on the development of an in vitro co-culture model which maintains the basolateral-apical architecture of the small intestine and allows for long-term survival of the parasite. Using transwell inserts, Caco-2 intestinal epithelial cells and IC-21 macrophages are co-cultured in the presence of Giardia trophozoites. Using the developed model, we show that Giardia trophozoites survive over 21 days and proliferate in a combination media of Caco-2 cell and Giardia medium. Giardia induces apoptosis of epithelial cells through caspase-3 activation and macrophages do not abrogate this response. Additionally, macrophages induce Caco-2 cells to secrete the pro-inflammatory cytokines, GRO and IL-8, a response abolished by Giardia indicating parasite induced suppression of the host immune response. The co-culture model provides additional complexity and information when compared to a single-cell model. This model will be a valuable tool for answering long-standing questions on host-parasite biology that may lead to discovery of new therapeutic interventions.
Hanly, Timothy J; Henson, Michael A
Sequential uptake of pentose and hexose sugars that compose lignocellulosic biomass limits the ability of pure microbial cultures to efficiently produce value-added bioproducts. In this work, we used dynamic flux balance modeling to examine the capability of mixed cultures of substrate-selective microbes to improve the utilization of glucose/xylose mixtures and to convert these mixed substrates into products. Co-culture simulations of Escherichia coli strains ALS1008 and ZSC113, engineered for glucose and xylose only uptake respectively, indicated that improvements in batch substrate consumption observed in previous experimental studies resulted primarily from an increase in ZSC113 xylose uptake relative to wild-type E. coli. The E. coli strain ZSC113 engineered for the elimination of glucose uptake was computationally co-cultured with wild-type Saccharomyces cerevisiae, which can only metabolize glucose, to determine if the co-culture was capable of enhanced ethanol production compared to pure cultures of wild-type E. coli and the S. cerevisiae strain RWB218 engineered for combined glucose and xylose uptake. Under the simplifying assumption that both microbes grow optimally under common environmental conditions, optimization of the strain inoculum and the aerobic to anaerobic switching time produced an almost twofold increase in ethanol productivity over the pure cultures. To examine the effect of reduced strain growth rates at non-optimal pH and temperature values, a break even analysis was performed to determine possible reductions in individual strain substrate uptake rates that resulted in the same predicted ethanol productivity as the best pure culture. © 2010 Wiley Periodicals, Inc.
Otsuka, Hidenori; Sasaki, Kohei; Okimura, Saya; Nagamura, Masako; Nakasone, Yuichi
Microfabrication and micropatterning techniques in tissue engineering offer great potential for creating and controlling cellular microenvironments including cell–matrix interactions, soluble stimuli and cell–cell interactions. Here, we present a novel approach to generate layered patterning of hepatocyte spheroids on micropatterned non-parenchymal feeder cells using microfabricated poly(ethylene glycol) (PEG) hydrogels. Micropatterned PEG-hydrogel-treated substrates with two-dimensional arrays of gelatin circular domains (ϕ = 100 μm) were prepared by photolithographic method. Only on the critical structure of PEG hydrogel with perfect protein rejection, hepatocytes were co-cultured with non-parenchymal cells to be led to enhanced hepatocyte functions. Then, we investigated the mechanism of the functional enhancement in co-culture with respect to the contributions of soluble factors and direct cell–cell interactions. In particular, to elucidate the influence of soluble factors on hepatocyte function, hepatocyte spheroids underlaid with fibroblasts (NIH/3T3 mouse fibroblasts) or endothelial cells (BAECs: bovine aortic endothelial cells) were compared with physically separated co-culture of hepatocyte monospheroids with NIH3T3 or BAEC using trans-well culture systems. Our results suggested that direct heterotypic cell-to-cell contact and soluble factors, both of these between hepatocytes and fibroblasts, significantly enhanced hepatocyte functions. In contrast, direct heterotypic cell-to-cell contact between hepatocytes and endothelial cells only contributed to enhance hepatocyte functions. This patterning technique can be a useful experimental tool for applications in basic science, drug screening and tissue engineering, as well as in the design of artificial liver devices. (paper)
Lorena Valdés Varela
Full Text Available The intestinal overgrowth of Clostridium difficile, often after disturbance of the gut microbiota by antibiotic treatment, leads to C. difficile infection (CDI which manifestation ranges from mild diarrhoea to life-threatening conditions. The increasing CDI incidence, not only in compromised subjects but also in traditionally considered low-risk populations, together with the frequent relapses of the disease, has attracted the interest for prevention/therapeutic options. Among these, probiotics, prebiotics or synbiotics constitute a promising approach. In this study we determined the potential of selected Bifidobacterium strains for the inhibition of C. difficile growth and toxicity in different carbon sources. We conducted co-cultures of the toxigenic strain C. difficile LMG21717 with four Bifidobacterium strains (Bifidobacterium longum IPLA20022, Bifidobacterium breve IPLA20006, Bifidobacterium bifidum IPLA20015, and Bifidobacterium animalis subsp. lactis Bb12 in the presence of various prebiotic substrates (Inulin, Synergy and Actilight or glucose, and compared the results with those obtained for the corresponding mono-cultures. C. difficile and bifidobacteria levels were quantified by qPCR; the pH and the production of short chain fatty acids was also determined. Moreover, supernatants of the cultures were collected to evaluate their toxicity using a recently developed model. Results showed that co-culture with B. longum IPLA20022 and B. breve IPLA20006 in the presence of short-chain fructooligosaccharides, but not of Inulin, as carbon source significantly reduced the growth of the pathogen. With the sole exception of B. animalis Bb12, whose growth was enhanced, the presence of C. difficile did not show major effects upon the growth of the bifidobacteria. In accordance with the growth data, B. longum and B. breve were the strains showing higher reduction in the toxicity of the co-culture supernatants.
Takagi, Risa; Tsujikawa, Yuji; Nomoto, Ryohei; Osawa, Ro
Lactobacillus delbrueckii TU-1, which apparently takes intact inulin into its cells and then degrades it intracellularly, was co-cultured in vitro with L. paracasei KTN-5, an extracellular inulin degrader; or L. plantarum 22A-3, a strain that is able to utilize fructose but not inulin; or both in order to prequalify inulin as a prebiotic agent in vivo. When L. delbrueckii TU-1 was co-cultured with L. paracasei KTN-5 on fructose or inulin, the growth of L. delbrueckii TU-1 on inulin was markedly higher than that of L. paracasei KTN-5, whereas the growth of L. delbrueckii TU-1 on fructose was much lower than that of L. paracasei KTN-5. These results suggest that L. delbrueckii TU-1 and L. paracasei KTN-5 were efficient at utilizing inulin and fructose, respectively. When L. plantarum 22A-3 was co-cultured with L. delbrueckii TU-1 on inulin, the growth of L. plantarum 22A-3 was enhanced by L. paracasei KTN-5 but not by L. delbrueckii TU-1, suggesting that the fructose moiety that L. paracasei KTN-5 released temporarily into the medium was "scavenged" by L. plantarum 22A-3. Thus, L. delbrueckii TU-1, L. paracasei KTN-5, and L. plantarum 22A-3 were then cultured altogether on inulin. The growth of L. delbrueckii TU-1 was unaffected but that of L. paracasei KTN-5 was markedly suppressed. This evidence suggests that prebiotic use of inulin supported the selective growth of intracellular inulin degraders such as L. delbrueckii rather than extracellular inulin degraders such as L. paracasei in the host microbiota.
Schütte, Julia; Hagmeyer, Britta; Holzner, Felix; Kubon, Massimo; Werner, Simon; Freudigmann, Christian; Benz, Karin; Böttger, Jan; Gebhardt, Rolf; Becker, Holger; Stelzle, Martin
In order to study possible toxic side effects of potential drug compounds in vitro a reliable test system is needed. Predicting liver toxicity presents a major challenge of particular importance as liver cells grown in a cell culture suffer from a rapid loss of their liver specific functions. Therefore we are developing a new microfluidic test system for liver toxicity. This test system is based on an organ-like liver 3D co-culture of hepatocytes and endothelial cells. We devised a microfluidic chip featuring cell culture chambers with integrated electrodes for the assembly of liver sinusoids by dielectrophoresis. Fluid channels enable an organ-like perfusion with culture media and test compounds. Different chamber designs were studied and optimized with regard to dielectrophoretic force distribution, hydrodynamic flow profile, and cell trapping rate using numeric simulations. Based on simulation results a microchip was injection-moulded from COP. This chip allowed the assembly of viable hepatocytes and endothelial cells in a sinusoid-like fashion.
Mogensen, Klaus Bo; Kutter, Jörg Peter
Optical detection schemes continue to be favoured for measurements in microfluidic systems. A selection of the latest progress mainly within the last two years is critically reviewed. Emphasis is on integrated solutions, such as planar waveguides, coupling schemes to the outside world, evanescent...... to ease commercialisation of the devices. This work will hopefully result in more commercial products that benefit from integrated optics, because the impact on commercial devices so far has been modest....
Hou, Han Wei; Bhagat, Ali Asgar S.; Lee, Wong Cheng J.; Huang, Sha; Han, Jongyoon; Lim, Chwee Teck
Blood, a complex biological fluid, comprises 45% cellular components suspended in protein rich plasma. These different hematologic components perform distinct functions in vivo and thus the ability to efficiently fractionate blood into its individual components has innumerable applications in both clinical diagnosis and biological research. Yet, processing blood is not trivial. In the past decade, a flurry of new microfluidic based technologies has emerged to address this compelling problem. ...
Tesař, Václav; Bandulasena, H.C.H.
Roč. 50, č. 5 (2011), s. 1225-1233 ISSN 0723-4864 R&D Projects: GA ČR GA101/07/1499; GA AV ČR IAA200760705 Institutional research plan: CEZ:AV0Z20760514 Keywords : fluidics * bistable diverter valves * pressure-driven microfluidics Subject RIV: BK - Fluid Dynamics Impact factor: 1.735, year: 2011 http://www.springerlink.com/content/x4907p1908151522/
Full Text Available Direct detection and analysis of biomolecules and cells in physiological microenvironment is urgently needed for fast evaluation of biology and pharmacy. The past several years have witnessed remarkable development opportunities in vitro organs and tissues models with multiple functions based on microfluidic devices, termed as “organ-on-a-chip”. Briefly speaking, it is a promising technology in rebuilding physiological functions of tissues and organs, featuring mammalian cell co-culture and artificial microenvironment created by microchannel networks. In this review, we summarized the advances in studies of heart-, vessel-, liver-, neuron-, kidney- and Multi-organs-on-a-chip, and discussed some noteworthy potential on-chip detection schemes.
Garba, Abubakar; Acar, Delphine D; Roukaerts, Inge D M; Desmarets, Lowiese M B; Devriendt, Bert; Nauwynck, Hans J
Mesenchymal cells are multipotent stromal cells with self-renewal, differentiation and immunomodulatory capabilities. We aimed to develop a co-culture model for differentiating hematopoietic cells on top of immortalized mesenchymal cells for studying interactions between hematopoietic and mesenchymal cells, useful for adequately exploring the therapeutic potential of mesenchymal cells. In this study, we investigated the survival, proliferation and differentiation of porcine red bone marrow hematopoietic cells co-cultured with immortalized porcine bone marrow mesenchymal cells for a period of five weeks. Directly after collection, primary porcine bone marrow mesenchymal cells adhered firmly to the bottom of the culture plates and showed a fibroblast-like appearance, one week after isolation. Upon immortalization, porcine bone marrow mesenchymal cells were continuously proliferating. They were positive for simian virus 40 (SV40) large T antigen and the mesenchymal cell markers CD44 and CD55. Isolated red bone marrow cells were added to these immortalized mesenchymal cells. Five weeks post-seeding, 92±6% of the red bone marrow hematopoietic cells were still alive and their number increased 3-fold during five weekly subpassages on top of the immortalized mesenchymal cells. The red bone marrow hematopoietic cells were originally small and round; later, the cells increased in size. Some of them became elongated, while others remained round. Tiny dendrites appeared attaching hematopoietic cells to the underlying immortalized mesenchymal cells. Furthermore, weekly differential-quick staining of the cells indicated the presence of monoblasts, monocytes, macrophages and lymphocytes in the co-cultures. At three weeks of co-culture, flow cytometry analysis showed an increased surface expression of CD172a, CD14, CD163, CD169, CD4 and CD8 up to 37±0.8%, 40±8%, 41±4%, 23±3% and 19±5% of the hematopoietic cells, respectively. In conclusion, continuous mesenchymal cell
Ott, Mark; Yang, J; Barilla, J.; Crabbe, A.; Sarker, S. F.; Liu, Y.
Three-dimensional/3-D organotypic models of human intestinal epithelium mimic the differentiated form and function of parental tissues often not exhibited by 2-D monolayers and respond to Salmonella in ways that reflect in vivo infections. To further enhance the physiological relevance of 3-D models to more closely approximate in vivo intestinal microenvironments during infection, we developed and validated a novel 3-D intestinal co-culture model containing multiple epithelial cell types and phagocytic macrophages, and applied to study enteric infection by different Salmonella pathovars.
Salvatore, Viviana; Focaroli, Stefano; Teti, Gabriella; Mazzotti, Antonio; Falconi, Mirella
The progression of malignant tumors does not depend exclusively on the autonomous properties of cancer cells; it is also influenced by tumor stroma reactivity and is under strict microenvironmental control. By themselves, stromal cells are not malignant, and they maintain normal tissue structure and function. However, through intercellular interactions or by paracrine secretions from cancer cells, normal stromal cells acquire abnormal phenotypes that sustain cancer cell growth and tumor progression. In their dysfunctional state, fibroblast and immune cells produce chemokines and growth factors that stimulate cancer cell growth and invasion. In our previous work, we established an in vitro model based on a monolayer co-culture system of healthy human fibroblasts (HFs) and human osteosarcoma cells (the MG-63 cell line) that simulates the microenvironment of tumor cells and healthy cells. The coexistence between MG-63 cells and HFs allowed us to identify the YKL-40 protein as the main marker for verifying the influence of tumor cells grown in contact with healthy cells. In this study, we evaluated the interactions of HFs and MG-63 cells in a transwell co-culture system over 24 h, 48 h, 72 h, and 96 h. We analyzed the contributions of these populations to the tumor microenvironment during cancer progression, as measured by multiple markers. We examined the effect of siRNA knockdown of YKL-40 by tracking the subsequent changes in gene expression within the co-culture. We validated the expression of several genes, focusing on those involved in cancer cell invasion, inflammatory responses, and angiogenesis: TNF alpha, IL-6, MMP-1, MMP-9, and VEGF. We compared the results to those from a transwell co-culture without the YKL-40 knockdown. In a pro-inflammatory environment promoted by TNF alpha and IL-6, siRNA knockdown of YKL-40 caused a down-regulation of VEGF and MMP-1 expression in HFs. These findings demonstrated that the tumor microenvironment has an influence on the
Abbott, N Joan; Dolman, Diana E M; Drndarski, Svetlana; Fredriksson, Sarah M
In vitro blood-brain barrier (BBB) models using primary cultured brain endothelial cells are important for establishing cellular and molecular mechanisms of BBB function. Co-culturing with BBB-associated cells especially astrocytes to mimic more closely the in vivo condition leads to upregulation of the BBB phenotype in the brain endothelial cells. Rat brain endothelial cells (RBECs) are a valuable tool allowing ready comparison with in vivo studies in rodents; however, it has been difficult to obtain pure brain endothelial cells, and few models achieve a transendothelial electrical resistance (TEER, measure of tight junction efficacy) of >200 Ω cm(2), i.e. the models are still relatively leaky. Here, we describe methods for preparing high purity RBECs and neonatal rat astrocytes, and a co-culture method that generates a robust, stable BBB model that can achieve TEER >600 Ω cm(2). The method is based on >20 years experience with RBEC culture, together with recent improvements to kill contaminating cells and encourage BBB differentiation.Astrocytes are isolated by mechanical dissection and cell straining and are frozen for later co-culture. RBECs are isolated from 3-month-old rat cortices. The brains are cleaned of meninges and white matter and enzymatically and mechanically dissociated. Thereafter, the tissue homogenate is centrifuged in bovine serum albumin to separate vessel fragments from other cells that stick to the myelin plug. The vessel fragments undergo a second enzyme digestion to separate pericytes from vessels and break down vessels into shorter segments, after which a Percoll gradient is used to separate capillaries from venules, arterioles, and single cells. To kill remaining contaminating cells such as pericytes, the capillary fragments are plated in puromycin-containing medium and RBECs grown to 50-60% confluence. They are then passaged onto filters for co-culture with astrocytes grown in the bottom of the wells. The whole procedure takes ∼2
Honore, Anders H.; Thorsen, Michael; Skov, Thomas
(UPLC) coupled to high-resolution mass spectrometry (MS) via electrospray ionisation (ESI) operated in both positive and negative modes is regarded as the optimum instrumental technique. The applicability of a range of liquid chromatographic techniques ranging from ion-pair (IPC) and hydrophilic...... could be a potent approach to elucidation of the mechanism. The purpose of this review is to discuss the two pre-requisites for such a study-the compound classes expected in the co-cultures, and on the basis of these, the most suitable analytical technique(s). Ultrahigh-performance liquid chromatography...
Snyder-Keller, A; Costantini, L C; Graber, D J
Organotypic cultures of fetal or early postnatal striatum were used to assess striatal patch formation and maintenance in the presence or absence of dopaminergic and glutamatergic influences. Vibratome-cut slices of the striatum prepared from embryonic day 19 to postnatal day 4 rat pups were maintained in static culture on clear membrane inserts in Dulbecco's modified Eagle's medium/F12 (1:1) with 20% horse serum. Some were co-cultured with embryonic day 12-16 ventral mesencephalon and/or embryonic day 19 to postnatal day 4 cortex, which produced a dense dopaminergic innervation and a modest cortical innervation. Donors of striatal and cortical tissue were previously injected with bromo-deoxyuridine (BrdU) on embryonic days 13 and 14 in order to label striatal neurons destined to populate the patch compartment of the striatum. Patches of BrdU-immunoreactive cells were maintained in organotypic cultures of late prenatal (embryonic days 20-22) or early postnatal striatum in the absence of nigral dopaminergic or cortical glutamatergic influences. In slices taken from embryonic day 19 fetuses prior to the time of in vivo patch formation, patches were observed to form after 10 days in vitro, in 39% of nigral-striatal co-cultures compared to 6% of striatal slices cultured alone or in the presence of cortex only. Patches of dopaminergic fibers, revealed by tyrosine hydroxylase immunoreactivity, were observed in the majority of nigral-striatal co-cultures. Immunostaining for the AMPA-type glutamate receptor GluR1 revealed a dense patch distribution in nearly all cultures, which developed in embryonic day 19 cultures after at least six days in vitro. These findings indicate that striatal patch/matrix organization is maintained in organotypic culture, and can be induced to form in vitro in striatal slices removed from fetuses prior to the time of in vivo patch formation. Furthermore, dopaminergic innervation from co-cultured pieces of ventral mesencephalon enhances patch
Chwee Teck Lim
Full Text Available Blood, a complex biological fluid, comprises 45% cellular components suspended in protein rich plasma. These different hematologic components perform distinct functions in vivo and thus the ability to efficiently fractionate blood into its individual components has innumerable applications in both clinical diagnosis and biological research. Yet, processing blood is not trivial. In the past decade, a flurry of new microfluidic based technologies has emerged to address this compelling problem. Microfluidics is an attractive solution for this application leveraging its numerous advantages to process clinical blood samples. This paper reviews the various microfluidic approaches realized to successfully fractionate one or more blood components. Techniques to separate plasma from hematologic cellular components as well as isolating blood cells of interest including certain rare cells are discussed. Comparisons based on common separation metrics including efficiency (sensitivity, purity (selectivity, and throughput will be presented. Finally, we will provide insights into the challenges associated with blood-based separation systems towards realizing true point-of-care (POC devices and provide future perspectives.
Yip, Hon Ming; Li, John C. S.; Cui, Xin; Gao, Qiannan; Leung, Chi Chiu
As microfluidics has been applied extensively in many cell and biochemical applications, monitoring the related processes is an important requirement. In this work, we design and fabricate a high-throughput microfluidic device which contains 32 microchambers to perform automated parallel microfluidic operations and monitoring on an automated stage of a microscope. Images are captured at multiple spots on the device during the operations for monitoring samples in microchambers in parallel; yet the device positions may vary at different time points throughout operations as the device moves back and forth on a motorized microscopic stage. Here, we report an image-based positioning strategy to realign the chamber position before every recording of microscopic image. We fabricate alignment marks at defined locations next to the chambers in the microfluidic device as reference positions. We also develop image processing algorithms to recognize the chamber positions in real-time, followed by realigning the chambers to their preset positions in the captured images. We perform experiments to validate and characterize the device functionality and the automated realignment operation. Together, this microfluidic realignment strategy can be a platform technology to achieve precise positioning of multiple chambers for general microfluidic applications requiring long-term parallel monitoring of cell and biochemical activities. PMID:25133248
Yip, Hon Ming; Li, John C S; Xie, Kai; Cui, Xin; Prasad, Agrim; Gao, Qiannan; Leung, Chi Chiu; Lam, Raymond H W
As microfluidics has been applied extensively in many cell and biochemical applications, monitoring the related processes is an important requirement. In this work, we design and fabricate a high-throughput microfluidic device which contains 32 microchambers to perform automated parallel microfluidic operations and monitoring on an automated stage of a microscope. Images are captured at multiple spots on the device during the operations for monitoring samples in microchambers in parallel; yet the device positions may vary at different time points throughout operations as the device moves back and forth on a motorized microscopic stage. Here, we report an image-based positioning strategy to realign the chamber position before every recording of microscopic image. We fabricate alignment marks at defined locations next to the chambers in the microfluidic device as reference positions. We also develop image processing algorithms to recognize the chamber positions in real-time, followed by realigning the chambers to their preset positions in the captured images. We perform experiments to validate and characterize the device functionality and the automated realignment operation. Together, this microfluidic realignment strategy can be a platform technology to achieve precise positioning of multiple chambers for general microfluidic applications requiring long-term parallel monitoring of cell and biochemical activities.