scholarly journals A mesh microelectrode array for non-invasive electrophysiology within neural organoids

2020 ◽  
Author(s):  
Matthew McDonald ◽  
David Sebinger ◽  
Lisa Brauns ◽  
Laura Gonzalez-Cano ◽  
Yotam Menuchin-Lasowski ◽  
...  
Keyword(s):  
Microelectrode Array ◽  
Single Cells ◽  
Three Dimensional ◽  
Microelectrode Arrays ◽  
Polymer Scaffolds ◽  
Neural Models ◽  
New Class ◽  
Non Invasive

AbstractOrganoids are emerging in vitro models of human physiology. Neural models require the evaluation of functional activity of single cells and networks, which is best measured by microelectrode arrays. The characteristics of organoids clash with existing in vitro or in vivo microelectrode arrays. With inspiration from implantable mesh electronics and growth of organoids on polymer scaffolds, we fabricated suspended hammock-like mesh microelectrode arrays for neural organoids. We have demonstrated the growth of organoids enveloping these meshes, their cultivation for at least nine months, and could measure spontaneous electrical activity within organoids. Our concept should enable a new class of microelectrode arrays for in vitro models of three-dimensional electrically active tissue.

scholarly journals Recent advances in three-dimensional microelectrode array technologies for in vitro and in vivo cardiac and neuronal interfaces

2021 ◽  
Vol 171 ◽  
pp. 112687
Author(s):  
Jong Seob Choi ◽  
Heon Joon Lee ◽  
Swaminathan Rajaraman ◽  
Deok-Ho Kim
Keyword(s):  
Microelectrode Array ◽  
Three Dimensional ◽  
Recent Advances

scholarly journals Non-Invasive Quantification of the Growth of Cancer Cell Colonies by a Portable Optical Coherence Tomography

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 35 ◽  
Author(s):  
Meng-Tsan Tsai ◽  
Bo-Huei Huang ◽  
Chun-Chih Yeh ◽  
Kin Fong Lei ◽  
Ngan-Ming Tsang
Keyword(s):  
Optical Coherence Tomography ◽  
Cancer Cell ◽  
Cellular Response ◽  
Tumor Development ◽  
Three Dimensional ◽  
Cancer Cell Line ◽  
Optical Coherence ◽  
Non Invasive

Investigation of tumor development is essential in cancer research. In the laboratory, living cell culture is a standard bio-technology for studying cellular response under tested conditions to predict in vivo cellular response. In particular, the colony formation assay has become a standard experiment for characterizing the tumor development in vitro. However, quantification of the growth of cell colonies under a microscope is difficult because they are suspended in a three-dimensional environment. Thus, optical coherence tomography (OCT) imaging was develop in this study to monitor the growth of cell colonies. Cancer cell line of Huh 7 was used and the cells were applied on a layer of agarose hydrogel, i.e., a non-adherent surface. Then, cell colonies were gradually formed on the surface. The OCT technique was used to scan the cell colonies every day to obtain quantitative data for describing their growth. The results revealed the average volume increased with time due to the formation of cell colonies day-by-day. Additionally, the distribution of cell colony volume was analyzed to show the detailed information of the growth of the cell colonies. In summary, the OCT provides a non-invasive quantification technique for monitoring the growth of the cell colonies. From the OCT images, objective and precise information is obtained for higher prediction of the in vivo tumor development.

scholarly journals Structure-based Design of CDC42 Effector Interaction Inhibitors For the Treatment of Cancer

2021 ◽  
Author(s):  
Sohail Jahid ◽  
Jose A. Ortega ◽  
Linh M. Vuong ◽  
Isabella Maria Acquistapace ◽  
Stephanie J. Hachey ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Three Dimensional ◽  
Pharmacokinetic Profile ◽  
Computer Aided Drug Design ◽  
New Class ◽  
Downstream Effectors ◽  
And Control ◽  
Braf Mutant

CDC42 family GTPases (RHOJ, RHOQ, CDC42) are upregulated but rarely mutated in cancer and control both the ability of tumor cells to invade surrounding tissues and the ability of endothelial cells to vascularize tumors. Here we use computer-aided drug design to discover a new chemical entity (ARN22089) that targets CDC42 GTPases and blocks CDC42 effector interactions without affecting the binding between closely related GTPases (RAC1, RAS, RAL) and their downstream effectors. Our lead compound has broad activity against a panel of cancer cell lines, inhibits S6 phosphorylation and MAPK activation, activates pro-inflammatory and apoptotic signaling, and blocks tumor growth and angiogenesis in three-dimensional vascularized microtumor models (VMT) in vitro. In addition, ARN22089 has a favorable pharmacokinetic profile and can inhibit the growth of BRAF mutant mouse melanomas and patient-derived xenografts in vivo. Taken together, this work identifies a promising new class of therapeutic agents that influence tumor growth by modulating CDC42 signaling in both the tumor cell and its microenvironment.

scholarly journals In Vivo Dopamine Detection and Single Unit Recordings Using Intracortical Glassy Carbon Microelectrode Arrays

MRS Advances ◽  
2018 ◽  
Vol 3 (29) ◽  
pp. 1629-1634 ◽  
Author(s):  
Elisa Castagnola ◽  
Nasim Winchester Vahidi ◽  
Surabhi Nimbalkar ◽  
Srihita Rudraraju ◽  
Marvin Thielk ◽  
...  
Keyword(s):  
Glassy Carbon ◽  
Neural Activity ◽  
Microelectrode Array ◽  
Flexible Substrate ◽  
Microelectrode Arrays ◽  
European Starling ◽  
Dopamine Detection ◽  
Vertical Spacing

ABSTRACTIn this study, we present a 4-channel intracortical glassy carbon (GC) microelectrode array on a flexible substrate for the simultaneous in vivo neural activity recording and dopamine (DA) concentration measurement at four different brain locations (220µm vertical spacing). The ability of GC microelectrodes to detect DA was firstly assessed in vitro in phosphate-buffered saline solution and then validated in vivo measuring spontaneous DA concentration in the Striatum of European Starling songbird through fast scan cyclic voltammetry(FSCV). The capability of GC microelectrode arrays and commercial penetrating metal microelectrode arrays to record neural activity from the Caudomedial Neostriatum of European starling songbird was compared. Preliminary results demonstrated the ability of GC microelectrodes in detecting neurotransmitters release and recording neural activity in vivo. GC microelectrodes array may, therefore, offer a new opportunity to understand the intimate relations linking electrophysiological parameters with neurotransmitters release.

scholarly journals Prospect of in vitro Bile Fluids Collection in Improving Cell-Based Assay of Liver Function

2021 ◽  
Vol 3 ◽  
Author(s):  
Astia Rizki-Safitri ◽  
Fumiya Tokito ◽  
Masaki Nishikawa ◽  
Minoru Tanaka ◽  
Kazuya Maeda ◽  
...  
Keyword(s):  
Cell Culture ◽  
Liver Function ◽  
Three Dimensional ◽  
Drug Clearance ◽  
Matrix Proteins ◽  
Chemical Analyses ◽  
Non Invasive ◽  
Cell Sources

The liver plays a pivotal role in the clearance of drugs. Reliable assays for liver function are crucial for various metabolism investigation, including toxicity, disease, and pre-clinical testing for drug development. Bile is an aqueous secretion of a functioning liver. Analyses of bile are used to explain drug clearance and related effects and are thus important for toxicology and pharmacokinetic research. Bile fluids collection is extensively performed in vivo, whereas this process is rarely reproduced as in the in vitro studies. The key to success is the technology involved, which needs to satisfy multiple criteria. To ensure the accuracy of subsequent chemical analyses, certain amounts of bile are needed. Additionally, non-invasive and continuous collections are preferable in view of cell culture. In this review, we summarize recent progress and limitations in the field. We highlight attempts to develop advanced liver cultures for bile fluids collection, including methods to stimulate the secretion of bile in vitro. With these strategies, researchers have used a variety of cell sources, extracellular matrix proteins, and growth factors to investigate different cell-culture environments, including three-dimensional spheroids, cocultures, and microfluidic devices. Effective combinations of expertise and technology have the potential to overcome these obstacles to achieve reliable in vitro bile assay systems.

scholarly journals Development and Application of an Additively Manufactured Calcium Chloride Nebulizer for Alginate 3D-Bioprinting Purposes

2018 ◽  
Vol 9 (4) ◽  
pp. 63 ◽  
Author(s):  
Lukas Raddatz ◽  
Antonina Lavrentieva ◽  
Iliyana Pepelanova ◽  
Janina Bahnemann ◽  
Dominik Geier ◽  
...  
Keyword(s):  
Cell Culture ◽  
Culture Media ◽  
Single Cells ◽  
Matrix Material ◽  
Three Dimensional ◽  
Culture Cell ◽  
3D Bioprinting ◽  
Cacl2 Solution

Three-dimensional (3D)-bioprinting enables scientists to mimic in vivo micro-environments and to perform in vitro cell experiments under more physiological conditions than is possible with conventional two-dimensional (2D) cell culture. Cell-laden biomaterials (bioinks) are precisely processed to bioengineer tissue three-dimensionally. One primarily used matrix material is sodium alginate. This natural biopolymer provides both fine mechanical properties when gelated and high biocompatibility. Commonly, alginate is 3D bioprinted using extrusion based devices. The gelation reaction is hereby induced by a CaCl2 solution in the building chamber after material extrusion. This established technique has two main disadvantages: (1) CaCl2 can have toxic effects on the cell-laden hydrogels by oxygen diffusion limitation and (2) good printing resolution in the CaCl2 solution is hard to achieve, since the solution needs to be removed afterwards and substituted by cell culture media. Here, we show an innovative approach of alginate bioprinting based on a CaCl2 nebulizer. The device provides CaCl2 mist to the building platform inducing the gelation. The necessary amount of CaCl2 could be decreased as compared to previous gelation strategies and limitation of oxygen transfer during bioprinting can be reduced. The device was manufactured using the MJP-3D printing technique. Subsequently, its digital blueprint (CAD file) can be modified and additive manufactured easily and mounted in various extrusion bioprinters. With our approach, a concept for a more gentle 3D Bioprinting method could be shown. We demonstrated that the concept of an ultrasound-based nebulizer for CaCl2 mist generation can be used for 3D bioprinting and that the mist-induced polymerization of alginate hydrogels of different concentrations is feasible. Furthermore, different cell-laden alginate concentrations could be used: Cell spheroids (mesenchymal stem cells) and single cells (mouse fibroblasts) were successfully 3D printed yielding viable cells and stable hydrogels after 24 h cultivation. We suggest our work to show a different and novel approach on alginate bioprinting, which could be useful in generating cell-laden hydrogel constructs for e.g., drug screening or (soft) tissue engineering applications.

scholarly journals Fabrication of Subretinal 3D Microelectrodes with Hexagonal Arrangement

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 467 ◽  
Author(s):  
Hee Won Seo ◽  
Namju Kim ◽  
Sohee Kim
Keyword(s):  
Integrated Circuit ◽  
Microelectrode Array ◽  
3D Structure ◽  
Three Dimensional ◽  
Active Electrode ◽  
Prosthetic Devices ◽  
In Vivo Experiments ◽  
Hexagonal Arrangement

This study presents the fabrication of three-dimensional (3D) microelectrodes for subretinal stimulation, to accommodate adjacent return electrodes surrounding a stimulating electrode. For retinal prosthetic devices, the arrangement of return electrodes, the electrode size and spacing should be considered together, to reduce the undesired dissipation of electric currents. Here, we applied the hexagonal arrangement to the microelectrode array for the localized activation of retinal cells and better visual acuity. To provide stimuli more efficiently to non-spiking neurons, a 3D structure was created through a customized pressing process, utilizing the elastic property of the materials used in the fabrication processes. The diameter and pitch of the Pt-coated electrodes were 150 μm and 350 μm, respectively, and the height of the protruded electrodes was around 20 μm. The array consisted of 98 hexagonally arranged electrodes, supported by a flexible and transparent polydimethylsiloxane (PDMS) base, with a thickness of 140 μm. Also, the array was coated with 2 μm-thick parylene-C, except the active electrode sites, for more focused stimulation. Finally, the electrochemical properties of the fabricated microelectrodes were characterized, resulting in the mean impedance of 384.87 kΩ at 1 kHz and the charge storage capacity (CSC) of 2.83 mC·cm−2. The fabricated microelectrodes are to be combined with an integrated circuit (IC) for additional in vitro and in vivo experiments.

scholarly journals Three-Dimensional Aggregated Spheroid Model of Hepatocellular Carcinoma Using a 96-Pillar/Well Plate

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4949
Author(s):  
Sang-Yun Lee ◽  
Yvonne Teng ◽  
Miseol Son ◽  
Bosung Ku ◽  
Hyun Ju Hwang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Drug Screening ◽  
Immune Cell ◽  
Single Cells ◽  
Three Dimensional ◽  
Cell Interaction ◽  
Screening Assay ◽  
Cytokine Activation

A common method of three-dimensional (3D) cell cultures is embedding single cells in Matrigel. Separated cells in Matrigel migrate or grow to form spheroids but lack cell-to-cell interaction, which causes difficulty or delay in forming mature spheroids. To address this issue, we proposed a 3D aggregated spheroid model (ASM) to create large single spheroids by aggregating cells in Matrigel attached to the surface of 96-pillar plates. Before gelling the Matrigel, we placed the pillar inserts into blank wells where gravity allowed the cells to gather at the curved end. In a drug screening assay, the ASM with Hepatocellular carcinoma (HCC) cell lines showed higher drug resistance compared to both a conventional spheroid model (CSM) and a two-dimensional (2D) cell culture model. With protein expression, cytokine activation, and penetration analysis, the ASM showed higher expression of cancer markers associated with proliferation (p-AKT, p-Erk), tight junction formation (Fibronectin, ZO-1, Occludin), and epithelial cell identity (E-cadherin) in HCC cells. Furthermore, cytokine factors were increased, which were associated with immune cell recruitment/activation (MIF-3α), extracellular matrix regulation (TIMP-2), cancer interaction (IL-8, TGF-β2), and angiogenesis regulation (VEGF-A). Compared to CSM, the ASM also showed limited drug penetration in doxorubicin, which appears in tissues in vivo. Thus, the proposed ASM better recapitulated the tumor microenvironment and can provide for more instructive data during in vitro drug screening assays of tumor cells and improved prediction of efficacious drugs in HCC patients.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

Conjugates of Classical DNA/RNA Binder with Nucleobase: Chemical, Biochemical and Biomedical Applications

2019 ◽  
Vol 26 (30) ◽  
pp. 5609-5624
Author(s):  
Dijana Saftić ◽  
Željka Ban ◽  
Josipa Matić ◽  
Lidija-Marija Tumirv ◽  
Ivo Piantanida
Keyword(s):  
Molecular Weight ◽  
Small Molecules ◽  
Biomedical Applications ◽  
Protein Targets ◽  
New Class ◽  
Rna Targets ◽  
Covalently Linked ◽  
Structural Aspects

: Among the most intensively studied classes of small molecules (molecular weight < 650) in biomedical research are small molecules that non-covalently bind to DNA/RNA, and another intensively studied class is nucleobase derivatives. Both classes have been intensively elaborated in many books and reviews. However, conjugates consisting of DNA/RNA binder covalently linked to nucleobase are much less studied and have not been reviewed in the last two decades. Therefore, this review summarized reports on the design of classical DNA/RNA binder – nucleobase conjugates, as well as data about their interactions with various DNA or RNA targets, and even in some cases protein targets are involved. According to these data, the most important structural aspects of selective or even specific recognition between small molecule and target are proposed, and where possible related biochemical and biomedical aspects were discussed. The general conclusion is that this, rather new class of molecules showed an amazing set of recognition tools for numerous DNA or RNA targets in the last two decades, as well as few intriguing in vitro and in vivo selectivities. Several lead research lines show promising advancements toward either novel, highly selective markers or bioactive, potentially druggable molecules.

Sign in / Sign up

Export Citation Format

Share Document