| 1. |
- Cunha, André B., et al.
(författare)
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Development of a Smart Wireless Multisensor Platform for an Optogenetic Brain Implant
- 2024
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Ingår i: Sensors. - 1424-8220. ; 24:2
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Tidskriftsartikel (refereegranskat)abstract
- Implantable cell replacement therapies promise to completely restore the function of neural structures, possibly changing how we currently perceive the onset of neurodegenerative diseases. One of the major clinical hurdles for the routine implementation of stem cell therapies is poor cell retention and survival, demanding the need to better understand these mechanisms while providing precise and scalable approaches to monitor these cell-based therapies in both pre-clinical and clinical scenarios. This poses significant multidisciplinary challenges regarding planning, defining the methodology and requirements, prototyping and different stages of testing. Aiming toward an optogenetic neural stem cell implant controlled by a smart wireless electronic frontend, we show how an iterative development methodology coupled with a modular design philosophy can mitigate some of these challenges. In this study, we present a miniaturized, wireless-controlled, modular multisensor platform with fully interfaced electronics featuring three different modules: an impedance analyzer, a potentiostat and an optical stimulator. We show the application of the platform for electrical impedance spectroscopy-based cell monitoring, optical stimulation to induce dopamine release from optogenetically modified neurons and a potentiostat for cyclic voltammetry and amperometric detection of dopamine release. The multisensor platform is designed to be used as an opto-electric headstage for future in vivo animal experiments.
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| 2. |
- Esmail Tehrani, Sheida, et al.
(författare)
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Hydrogen Peroxide Detection Using Prussian Blue-modified 3D Pyrolytic Carbon Microelectrodes
- 2021
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Ingår i: Electroanalysis. - : John Wiley & Sons. - 1040-0397 .- 1521-4109. ; 33:12, s. 2516-2528
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Tidskriftsartikel (refereegranskat)abstract
- A highly sensitive amperometric Prussian blue-based hydrogen peroxide sensor was developed using 3D pyrolytic carbon microelectrodes. A 3D printed multielectrode electrochemical cell enabled simultaneous highly reproducible Prussian blue modification on multiple carbon electrodes. The effect of oxygen plasma pre-treatment and deposition time on Prussian blue electrodeposition was studied. The amperometric response of 2D and 3D sensors to the addition of hydrogen peroxide in mu M and sub-mu M concentrations in phosphate buffer was investigated. A high sensitivity comparable to flow injection systems and a detection limit of 0.16 mu M was demonstrated with 3D pyrolytic carbon microelectrodes at stirred batch condition
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| 3. |
- Fiorenzano, Alessandro, et al.
(författare)
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Single-cell transcriptomics captures features of human midbrain development and dopamine neuron diversity in brain organoids
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Three-dimensional brain organoids have emerged as a valuable model system for studies of human brain development and pathology. Here we establish a midbrain organoid culture system to study the developmental trajectory from pluripotent stem cells to mature dopamine neurons. Using single cell RNA sequencing, we identify the presence of three molecularly distinct subtypes of human dopamine neurons with high similarity to those in developing and adult human midbrain. However, despite significant advancements in the field, the use of brain organoids can be limited by issues of reproducibility and incomplete maturation which was also observed in this study. We therefore designed bioengineered ventral midbrain organoids supported by recombinant spider-silk microfibers functionalized with full-length human laminin. We show that silk organoids reproduce key molecular aspects of dopamine neurogenesis and reduce inter-organoid variability in terms of cell type composition and dopamine neuron formation.
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| 4. |
- Kajtez, Janko, et al.
(författare)
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3D biomaterial models of human brain disease
- 2021
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Ingår i: Neurochemistry International. - : Elsevier BV. - 0197-0186. ; 147
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Tidskriftsartikel (refereegranskat)abstract
- Inherent limitations of the traditional approaches to study brain function and disease, such as rodent models and 2D cell culture platforms, have led to the development of 3D in vitro cell culture systems. These systems, products of multidisciplinary efforts encompassing stem cell biology, materials engineering, and biofabrication, have quickly shown great potential to mimic biochemical composition, structural properties, and cellular morphology and diversity found in the native brain tissue. Crucial to these developments have been the advancements in stem cell technology and cell reprogramming protocols that allow reproducible generation of human subtype-specific neurons and glia in laboratory conditions. At the same time, biomaterials have been designed to provide cells in 3D with a microenvironment that mimics functional and structural aspects of the native extracellular matrix with increasing fidelity. In this article, we review the use of biomaterials in 3D in vitro models of neurological disorders with focus on hydrogel technology and with biochemical composition and physical properties of the in vivo environment as reference.
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| 5. |
- Kajtez, Janko, et al.
(författare)
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3D-Printed Soft Lithography for Complex Compartmentalized Microfluidic Neural Devices
- 2020
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Ingår i: Advanced Science. - : Wiley. - 2198-3844. ; 7:16
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Tidskriftsartikel (refereegranskat)abstract
- Compartmentalized microfluidic platforms are an invaluable tool in neuroscience research. However, harnessing the full potential of this technology remains hindered by the lack of a simple fabrication approach for the creation of intricate device architectures with high-aspect ratio features. Here, a hybrid additive manufacturing approach is presented for the fabrication of open-well compartmentalized neural devices that provides larger freedom of device design, removes the need for manual postprocessing, and allows an increase in the biocompatibility of the system. Suitability of the method for multimaterial integration allows to tailor the device architecture for the long-term maintenance of healthy human stem-cell derived neurons and astrocytes, spanning at least 40 days. Leveraging fast-prototyping capabilities at both micro and macroscale, a proof-of-principle human in vitro model of the nigrostriatal pathway is created. By presenting a route for novel materials and unique architectures in microfluidic systems, the method provides new possibilities in biological research beyond neuroscience applications.
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| 6. |
- Kajtez, Janko, et al.
(författare)
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Embedded 3D Printing in Self-Healing Annealable Composites for Precise Patterning of Functionally Mature Human Neural Constructs
- 2022
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Ingår i: Advanced science (Weinheim, Baden-Wurttemberg, Germany). - : Wiley. - 2198-3844. ; 9:25
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Tidskriftsartikel (refereegranskat)abstract
- Human in vitro models of neural tissue with tunable microenvironment and defined spatial arrangement are needed to facilitate studies of brain development and disease. Towards this end, embedded printing inside granular gels holds great promise as it allows precise patterning of extremely soft tissue constructs. However, granular printing support formulations are restricted to only a handful of materials. Therefore, there has been a need for novel materials that take advantage of versatile biomimicry of bulk hydrogels while providing high-fidelity support for embedded printing akin to granular gels. To address this need, Authors present a modular platform for bioengineering of neuronal networks via direct embedded 3D printing of human stem cells inside Self-Healing Annealable Particle-Extracellular matrix (SHAPE) composites. SHAPE composites consist of soft microgels immersed in viscous extracellular-matrix solution to enable precise and programmable patterning of human stem cells and consequent generation mature subtype-specific neurons that extend projections into the volume of the annealed support. The developed approach further allows multi-ink deposition, live spatial and temporal monitoring of oxygen levels, as well as creation of vascular-like channels. Due to its modularity and versatility, SHAPE biomanufacturing toolbox has potential to be used in applications beyond functional modeling of mechanically sensitive neural constructs.
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| 7. |
- Pupinyo, Naricha, et al.
(författare)
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Impedimetric melanoma invasion assay device using a simple paper membrane and stencil-printed electrode on PMMA substrate
- 2020
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Ingår i: Sensing and Bio-Sensing Research. - : Elsevier BV. - 2214-1804. ; 29
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Tidskriftsartikel (refereegranskat)abstract
- The transwell assay is currently the most popular approach to studying cellular invasion due to its ease of use and readout, and the possibility for quantitative measurements. However, it only allows end-point measurements without the possibility for real-time tracking of the dynamics of cell movement during an invasion. Moreover, it requires cell labeling, and construction of customized devices is hampered by the commercial standard membrane inserts, only available in certain designs. Recently, paper has been used as a scaffold for three-dimensional (3D) cell cultures. Because of its microfibrous structure and easy handling, it could be a versatile alternative as a membrane insert in customized devices. Here, we develop a low-cost real-time invasion assay device using paper as an alternative membrane insert. The device was designed for two-electrode impedance measurements and fabricated using CNC micromilling. It also comprised a disposable low-cost stencil-printed working electrode on a poly(methyl methacrylate) substrate below the membrane and glassy carbon counter electrode above the membrane inserted in a specially designed lid. Thus, the impedance measurements during cell invasion addressed the entire membrane. We demonstrated the function of the device by monitoring the invasion of B16 melanoma 4A5 cells from a mouse using insulin growth factor-1 as the chemoattractant. The cell invasion on paper was visualized using scanning electron microscopy and confocal microscopy with Z-stack 3D imaging. Melanoma cell invasion could be observed within 7 h after the chemoattractant treatment, which was faster than the conventional assay and less likely to be influenced by cell proliferation.
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| 8. |
- Simsa, Robin, et al.
(författare)
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Brain organoid formation on decellularized porcine brain ECM hydrogels
- 2021
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- Human brain tissue models such as cerebral organoids are essential tools for developmental and biomedical research. Current methods to generate cerebral organoids often utilize Matrigel as an external scaffold to provide structure and biologically relevant signals. Matrigel however is a nonspecific hydrogel of mouse tumor origin and does not represent the complexity of the brain protein environment. In this study, we investigated the application of a decellularized adult porcine brain extracellular matrix (B-ECM) which could be processed into a hydrogel (B-ECM hydrogel) to be used as a scaffold for human embryonic stem cell (hESC)-derived brain organoids. We decellularized pig brains with a novel detergent- and enzyme-based method and analyzed the biomaterial properties, including protein composition and content, DNA content, mechanical characteristics, surface structure, and antigen presence. Then, we compared the growth of human brain organoid models with the B-ECM hydrogel or Matrigel controls in vitro. We found that the native brain source material was successfully decellularized with little remaining DNA content, while Mass Spectrometry (MS) showed the loss of several brain-specific proteins, while mainly different collagen types remained in the B-ECM. Rheological results revealed stable hydrogel formation, starting from B-ECM hydrogel concentrations of 5 mg/mL. hESCs cultured in B-ECM hydrogels showed gene expression and differentiation outcomes similar to those grown in Matrigel. These results indicate that B-ECM hydrogels can be used as an alternative scaffold for human cerebral organoid formation, and may be further optimized for improved organoid growth by further improving protein retention other than collagen after decellularization.
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