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Soscia D, Belle A, Fischer N, Enright H, Sales A, Osburn J, Benett W, Mukerjee E, Kulp K, Pannu S, Wheeler E. Controlled placement of multiple CNS cell populations to create complex neuronal cultures. PLoS One 2017; 12:e0188146. [PMID: 29161298 PMCID: PMC5697820 DOI: 10.1371/journal.pone.0188146] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/01/2017] [Indexed: 11/24/2022] Open
Abstract
In vitro brain-on-a-chip platforms hold promise in many areas including: drug discovery, evaluating effects of toxicants and pathogens, and disease modelling. A more accurate recapitulation of the intricate organization of the brain in vivo may require a complex in vitro system including organization of multiple neuronal cell types in an anatomically-relevant manner. Most approaches for compartmentalizing or segregating multiple cell types on microfabricated substrates use either permanent physical surface features or chemical surface functionalization. This study describes a removable insert that successfully deposits neurons from different brain areas onto discrete regions of a microelectrode array (MEA) surface, achieving a separation distance of 100 μm. The regional seeding area on the substrate is significantly smaller than current platforms using comparable placement methods. The non-permanent barrier between cell populations allows the cells to remain localized and attach to the substrate while the insert is in place and interact with neighboring regions after removal. The insert was used to simultaneously seed primary rodent hippocampal and cortical neurons onto MEAs. These cells retained their morphology, viability, and function after seeding through the cell insert through 28 days in vitro (DIV). Co-cultures of the two neuron types developed processes and formed integrated networks between the different MEA regions. Electrophysiological data demonstrated characteristic bursting features and waveform shapes that were consistent for each neuron type in both mono- and co-culture. Additionally, hippocampal cells co-cultured with cortical neurons showed an increase in within-burst firing rate (p = 0.013) and percent spikes in bursts (p = 0.002), changes that imply communication exists between the two cell types in co-culture. The cell seeding insert described in this work is a simple but effective method of separating distinct neuronal populations on microfabricated devices, and offers a unique approach to developing the types of complex in vitro cellular environments required for anatomically-relevant brain-on-a-chip devices.
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Affiliation(s)
- D. Soscia
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - A. Belle
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - N. Fischer
- Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - H. Enright
- Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - A. Sales
- Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - J. Osburn
- Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - W. Benett
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - E. Mukerjee
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - K. Kulp
- Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - S. Pannu
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - E. Wheeler
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
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Enright HA, Felix SH, Fischer NO, Mukerjee EV, Soscia D, Mcnerney M, Kulp K, Zhang J, Page G, Miller P, Ghetti A, Wheeler EK, Pannu S. Long-term non-invasive interrogation of human dorsal root ganglion neuronal cultures on an integrated microfluidic multielectrode array platform. Analyst 2016; 141:5346-57. [PMID: 27351032 DOI: 10.1039/c5an01728a] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Scientific studies in drug development and toxicology rely heavily on animal models, which often inaccurately predict the true response for human exposure. This may lead to unanticipated adverse effects or misidentified risks that result in, for example, drug candidate elimination. The utilization of human cells and tissues for in vitro physiological platforms has become a growing area of interest to bridge this gap and to more accurately predict human responses to drugs and toxins. The effects of new drugs and toxins on the peripheral nervous system are often investigated with neurons isolated from dorsal root ganglia (DRG), typically with one-time measurement techniques such as patch clamping. Here, we report the use of our multi-electrode array (MEA) platform for long-term noninvasive assessment of human DRG cell health and function. In this study, we acquired simultaneous optical and electrophysiological measurements from primary human DRG neurons upon chemical stimulation repeatedly through day in vitro (DIV) 23. Distinct chemical signatures were noted for the cellular responses evoked by each chemical stimulus. Additionally, the cell viability and function of the human DRG neurons were consistent through DIV 23. To the best of our knowledge, this is the first report on long-term measurements of the cell health and function of human DRG neurons on a MEA platform. Future generations will include higher electrode numbers in customized arrangements as well as integration with different tissue types on a single device. This platform will provide a valuable testing tool for both rodent and human cells, enabling a more comprehensive risk assessment for drug candidates and toxicants.
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Affiliation(s)
- H A Enright
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, USA
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Lorenz K, Kulp K. Cereal- and Root Starch Modification by Heat-Moisture Treatment. II. Functional Properties and Baking Potential. STARCH-STARKE 1982. [DOI: 10.1002/star.19820340303] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Abstract
Staling, as it is applied to bakery foods, is a generic term covering a number of changes that occur in the products during normal storage. Consumers judge staleness by direct perception, which provides a subjective estimate that represents an unconscious integration of many factors. This review will discuss the main components of staling: (1) physicochemical changes of bread and related products (firming and texture deterioration of crumb and loss of crispness of crust) and (2) flavor changes. Section I will cover current theories of changes of firming and textural changes. The starch component of flour is generally considered to be responsible for these staling reactions. Consequently, the physicochemical involvement of amylose, amylopectin in these reactions will be fully discussed and current evidence supporting these theories (rheological, chemical, X-rays) will be given. Interactions of starch and surface active agents and other complexing compounds will be presented in Section II. In Section III, contribution of minor flour components and bakery food ingredients will be evaluated. Section IV will focus on organoleptic deterioration of products, presenting flavor changes that were observed during staling bread. Section V will discuss structural changes of breads caused by enzymolysis during bread production and storage as related to staling. Following the theoretical section (Sections I to V), Section VI will focus on practical control of staling. This discussion will cover the following factors: formulation, surfactants, enzymes, storage, freezing, and packaging.
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