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| 2. |
- Ashammakhi, Nureddin, et al.
(författare)
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Modelling Brain in a Chip
- 2023
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Ingår i: The Journal of Craniofacial Surgery. - : Ovid Technologies (Wolters Kluwer Health). - 1049-2275 .- 1536-3732. ; 34:3, s. 845-847
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Azizian, Parnian, et al.
(författare)
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Magnetically Driven Manipulation of Nonmagnetic Liquid Marbles : Billiards with Liquid Marbles
- 2023
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Ingår i: Micromachines. - : MDPI AG. - 2072-666X. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Liquid marbles are droplets encapsulated by a layer of hydrophobic nanoparticles and have been extensively employed in digital microfluidics and lab-on-a-chip systems in recent years. In this study, magnetic liquid marbles were used to manipulate nonmagnetic liquid marbles. To achieve this purpose, a ferrofluid liquid marble (FLM) was employed and attracted toward an electromagnet, resulting in an impulse to a water liquid marble (WLM) on its way to the electromagnet. It was observed that the manipulation of the WLM by the FLM was similar to the collision of billiard balls except that the liquid marbles exhibited an inelastic collision. Taking the FLM as the projectile ball and the WLM as the other target balls, one can adjust the displacement and direction of the WLM precisely, similar to an expert billiard player. Firstly, the WLM displacement can be adjusted by altering the liquid marble volumes, the initial distances from the electromagnet, and the coil current. Secondly, the WLM direction can be adjusted by changing the position of the WLM relative to the connecting line between the FLM center and the electromagnet. Results show that when the FLM or WLM volume increases by five times, the WLM shooting distance approximately increases by 200% and decreases by 75%, respectively.
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| 4. |
- Habibey, Rouhollah, et al.
(författare)
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Engineered modular neuronal networks-on-chip represent structure-function relationship
- 2024
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Ingår i: Biosensors & bioelectronics. - : Elsevier BV. - 0956-5663 .- 1873-4235. ; 261
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Tidskriftsartikel (refereegranskat)abstract
- Brain function is substantially linked to the highly organized modular structure of neuronal networks. However, the structure of in vitro assembled neuronal circuits often exhibits variability, complicating the consistent recording of network functional output and its correlation to network structure. Therefore, engineering neuronal structures with predefined geometry and reproducible functional features is essential to precisely model in vivo neuronal circuits. Here, we engineered microchannel devices to assemble 2D and 3D modular networks. The microchannel devices were coupled with a multi-electrode array (MEA) electrophysiology system to enable recordings from circuits. Each network consisted of 64 modules connected to their adjacent modules by micron-sized channels. Modular circuits within microchannel devices showed enhanced activity and functional connectivity traits. This includes metrics such as connection weights, clustering coefficient, global efficiency, and the number of hub neurons with higher betweenness centrality. In addition, modular networks demonstrated an increased functional modularity score compared to the randomly formed circuits. Neurons within individual modules displayed uniform network characteristics and predominantly participated in their respective functional communities within the same or neighboring physical modules. These observations highlight that the modular network structure promotes the development of segregated functional connectivity traits while simultaneously enhancing the efficiency of overall network connectivity. Our findings emphasize the significant impact of physical constraints on the activity patterns and functional organization within engineered modular networks. These circuits, characterized by stable modular architecture and intricate functional dynamics—key features of the brain networks—offer a robust in vitro model for advancing neuroscience research.
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| 5. |
- Kavand, Hanie, et al.
(författare)
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Advanced Materials and Sensors for Microphysiological Systems: Focus on Electronic and Electro‐optical Interfaces
- 2021
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; , s. 2107876-2107876
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Tidskriftsartikel (refereegranskat)abstract
- Advanced in vitro cell culture systems or microphysiological systems (MPSs), including microfluidic organ-on-a-chip (OoC), are breakthrough technologies in biomedicine. These systems recapitulate features of human tissues outside of the body. They are increasingly being used to study the functionality of different organs for applications such as drug evolutions, disease modeling, and precision medicine. Currently, developers and endpoint users of these in vitro models promote how they can replace animal models or even be a better ethically neutral and humanized alternative to study pathology, physiology, and pharmacology. Although reported models show a remarkable physiological structure and function compared to the conventional two-dimensional cell culture, they are almost exclusively based on standard passive polymers or glass with none or minimal real-time stimuli and readout capacity. The next technology leap in reproducing in vivo-like functionality and real-time monitoring of tissue function could be realized with advanced functional materials and devices. This review describes the currently reported electronic and optical advanced materials for sensing and stimulation of MPS models. In addition, we give an overview of multi-sensing for Body-on-Chip platforms. Finally, we give our perspective on how advanced functional materials could be integrated into in vitro systems to precisely mimic human physiology.
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| 6. |
- Kawakita, Satoru, et al.
(författare)
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Rapid integration of screen-printed electrodes into thermoplastic organ-on-a-chip devices for real-time monitoring of trans-endothelial electrical resistance
- 2023
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Ingår i: Biomedical microdevices (Print). - : Springer Nature. - 1387-2176 .- 1572-8781. ; 25:4
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Tidskriftsartikel (refereegranskat)abstract
- Trans-endothelial electrical resistance (TEER) is one of the most widely used indicators to quantify the barrier integrity of endothelial layers. Over the last decade, the integration of TEER sensors into organ-on-a-chip (OOC) platforms has gained increasing interest for its efficient and effective measurement of TEER in OOCs. To date, microfabricated electrodes or direct insertion of wires has been used to integrate TEER sensors into OOCs, with each method having advantages and disadvantages. In this study, we developed a TEER-SPE chip consisting of carbon-based screen-printed electrodes (SPEs) embedded in a poly(methyl methacrylate) (PMMA)-based multi-layered microfluidic device with a porous poly(ethylene terephthalate) membrane in-between. As proof of concept, we demonstrated the successful cultures of hCMEC/D3 cells and the formation of confluent monolayers in the TEER-SPE chip and obtained TEER measurements for 4 days. Additionally, the TEER-SPE chip could detect changes in the barrier integrity due to shear stress or an inflammatory cytokine (i.e., tumor necrosis factor-& alpha;). The novel approach enables a low-cost and facile fabrication of carbon-based SPEs on PMMA substrates and the subsequent assembly of PMMA layers for rapid prototyping. Being cost-effective and cleanroom-free, our method lowers the existing logistical and technical barriers presenting itself as another step forward to the broader adoption of OOCs with TEER measurement capability.
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| 7. |
- Matthiesen, Isabelle, et al.
(författare)
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Metabolic Assessment of Human Induced Pluripotent Stem Cells-Derived Astrocytes and Fetal Primary Astrocytes : Lactate and Glucose Turnover
- 2022
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Ingår i: Biosensors. - : MDPI AG. - 2079-6374. ; 12:10, s. 839-
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Tidskriftsartikel (refereegranskat)abstract
- Astrocytes represent one of the main cell types in the brain and play a crucial role in brain functions, including supplying the energy demand for neurons. Moreover, they are important regulators of metabolite levels. Glucose uptake and lactate production are some of the main observable metabolic actions of astrocytes. To gain insight into these processes, it is essential to establish scalable and functional sources for in vitro studies of astrocytes. In this study, we compared the metabolic turnover of glucose and lactate in astrocytes derived from human induced pluripotent stem cell (hiPSC)-derived Astrocytes (hiAstrocytes) as a scalable astrocyte source to human fetal astrocytes (HFAs). Using a user-friendly, commercial flow-based biosensor, we could verify that hiAstrocytes are as glycogenic as their fetal counterparts, but their normalized metabolic turnover is lower. Specifically, under identical culture conditions in a defined media, HFAs have 2.3 times higher levels of lactate production compared to hiAstrocytes. In terms of glucose, HFAs have 2.1 times higher consumption levels than hiAstrocytes at 24 h. Still, as we describe their glycogenic phenotype, our study demonstrates the use of hiAstrocytes and flow-based biosensors for metabolic studies of astrocyte function.
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| 8. |
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| 9. |
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| 10. |
- Reyes, Darwin R., et al.
(författare)
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From animal testing to in vitro systems: advancing standardization in microphysiological systems
- 2024
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Ingår i: Lab on a Chip. - : Royal Society of Chemistry (RSC). - 1473-0197 .- 1473-0189. ; 24:5, s. 1076-1087
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Forskningsöversikt (refereegranskat)abstract
- Limitations with cell cultures and experimental animal-based studies have had the scientific and industrial communities searching for new approaches that can provide reliable human models for applications such as drug development, toxicological assessment, and in vitro pre-clinical evaluation. This has resulted in the development of microfluidic-based cultures that may better represent organs and organ systems in vivo than conventional monolayer cell cultures. Although there is considerable interest from industry and regulatory bodies in this technology, several challenges need to be addressed for it to reach its full potential. Among those is a lack of guidelines and standards. Therefore, a multidisciplinary team of stakeholders was formed, with members from the US Food and Drug Administration (FDA), the National Institute of Standards and Technology (NIST), European Union, academia, and industry, to provide a framework for future development of guidelines/standards governing engineering concepts of organ-on-a-chip models. The result of this work is presented here for interested parties, stakeholders, and other standards development organizations (SDOs) to foster further discussion and enhance the impact and benefits of these efforts.
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| 11. |
- Rezaeian, Masoud, et al.
(författare)
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The Effect of Non-Uniform Magnetic Field on the Efficiency of Mixing in Droplet-Based Microfluidics : A Numerical Investigation
- 2022
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Ingår i: Micromachines. - : MDPI AG. - 2072-666X. ; 13:10, s. 1661-
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Tidskriftsartikel (refereegranskat)abstract
- Achieving high efficiency and throughput in droplet-based mixing over a small characteristic length, such as microfluidic channels, is one of the crucial parameters in Lab-on-a-Chip (LOC) applications. One solution to achieve efficient mixing is to use active mixers in which an external power source is utilized to mix two fluids. One of these active methods is magnetic micromixers using ferrofluid. In this technique, magnetic nanoparticles are used to make one phase responsive to magnetic force, and then by applying a magnetic field, two fluid phases, one of which is magneto-responsive, will sufficiently mix. In this study, we investigated the effect of the magnetic field's characteristics on the efficiency of the mixing process inside droplets. When different concentrations of ferrofluids are affected by a constant magnetic field, there is no significant change in mixing efficiency. As the magnetic field intensifies, the magnetic force makes the circulation flow inside the droplet asymmetric, leading to chaotic advection, which creates a flow that increases the mixing efficiency. The results show that the use of magnetic fields is an effective method to enhance the mixing efficiency within droplets, and the efficiency of mixing increases from 65.4 to 86.1% by increasing the magnetic field intensity from 0 to 90 mT. Besides that, the effect of ferrofluid's concentration on the mixing efficiency is studied. It is shown that when the concentration of the ferrofluid changes from 0 to 0.6 mol/m(3), the mixing efficiency increases considerably. It is also shown that by changing the intensity of the magnetic field, the mixing efficiency increases by about 11%.
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| 12. |
- Zhu, Yangzhi, et al.
(författare)
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A Microfluidic Contact Lens to Address Contact Lens-Induced Dry Eye
- 2023
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 19:11
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Tidskriftsartikel (refereegranskat)abstract
- The contact lens (CL) industry has made great strides in improving CL-wearing experiences. However, a large amount of CL wearers continue to experience ocular dryness, known as contact lens-induced dry eye (CLIDE), stemming from the reduction in tear volume, tear film instability, increased tear osmolarity followed by inflammation and resulting in ocular discomfort and visual disturbances. In this article, to address tear film thinning between the CL and the ocular surface, the concept of using a CL with microchannels to deliver the tears from the pre-lens tear film (PrLTF) to the post-lens ocular surface using in vitro eye-blink motion is investigated. This study reports an eye-blink mimicking system with microfluidic poly(2-hydroxyethyl methacrylate) (poly(HEMA)) hydrogel with integrated microchannels to demonstrate eye-blink assisted flow through microchannels. This in vitro experimental study provides a proof-of-concept result that tear transport from PrLTF to post-lens tear film can be enhanced by an artificial eyelid motion in a pressure range of 0.1–5 kPa (similar to human eyelid pressure) through poly(HEMA) microchannels. Simulation is conducted to support the hypothesis. This work demonstrates the feasibility of developing microfluidic CLs with the potential to help prevent or minimize CLIDE and discomfort by the enhanced transport of pre-lens tears to the post-lens ocular surface.
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