Morphometric assessment of toxicant induced neuronal degeneration in full and restricted contact co-cultures of embryonic cortical rat neurons and astrocytes: using m-Dinitrobezene as a model neurotoxicant

Thermoplasmonic neural chip platform for in situ manipulation of neuronal connections in vitro

Cultured neuronal networks with a controlled structure have been widely studied as an in vitro model system to investigate the relationship between network structure and function. However, most cell culture techniques lack the ability to control network structures during cell cultivation, making it difficult to assess functional changes induced by specific structural changes. In this study, we present an in situ manipulation platform based on gold-nanorod-mediated thermoplasmonics to interrogate an in vitro network model. We find that it is possible to induce new neurite outgrowths, eliminate interconnecting neurites, and estimate functional relationships in matured neuronal networks. This method is expected to be useful for studying functional dynamics of neural networks under controlled structural changes.

Cultured neuron networks provide insight into network structure and function, but the ability to control network topology is a challenge. Here the authors develop a nanorod-mediated thermoplasmonics platform that enables the formation of new connections, the abolishment of existing connections, and the modulation of network activity during cultivation.

Morphometric and computational assessments to evaluate neuron survival and maturation within compartmentalized microfluidic devices: The influence of design variation on diffusion-driven nutrient transport

Burgeoning use of segregated microfluidic platforms that parse somas and neurites into discrete compartments is fueling unique examinations of neuronal structure and physiology in a manner impossible to achieve with non-compartmentalized systems. However, even though this line of axon-soma polarizing microfluidic devices stems from the same general design of a Campenot chamber set-up, slight deviations in device geometry appear to induce vastly different nutrient transport profiles that influence neuron survival and maturation. Here we examine the uptake of nerve growth factor (NGF) by a pheochromocytoma PC12 cell line cultured using two Campenot-like device designs, a "Standard" layout, representative of a commercial device, and a custom "Notch" layout, predicted to encourage more efficient nutrient transfer that gives rise to sustained neuron viability and extensive neurite elaboration. Exploiting in vitro culture schemes coupled with computational analyses, we identify the influence of device design geometry on the interplay between neuronal survival and maturation, gauged from morphometric assessments and the spatiotemporal distribution of NGF. Computer simulations of NGF transport within the devices revealed that the microfluidic neuron culture system is highly sensitive to change, where nutrient transport is intricately linked to device geometry and cell plating density, and premature depletion of nutrients is observed if specific design criteria are not met. This study underscores the importance of validating specific device geometries for a particular neuro-based assessment, while showcasing computational modeling as a powerful tool to achieve this goal.

Stem cells technology: a powerful tool behind new brain treatments

Stem cell research has recently become a hot research topic in biomedical research due to the foreseen unlimited potential of stem cells in tissue engineering and regenerative medicine. For many years, medicine has been facing intense challenges, such as an insufficient number of organ donations that is preventing clinicians to fulfill the increasing needs. To try and overcome this regrettable matter, research has been aiming at developing strategies to facilitate the in vitro culture and study of stem cells as a tool for tissue regeneration. Meanwhile, new developments in the microfluidics technology brought forward emerging cell culture applications that are currently allowing for a better chemical and physical control of cellular microenvironment. This review presents the latest developments in stem cell research that brought new therapies to the clinics and how the convergence of the microfluidics technology with stem cell research can have positive outcomes on the fields of regenerative medicine and high-throughput screening. These advances will bring new translational solutions for drug discovery and will upgrade in vitro cell culture to a new level of accuracy and performance. We hope this review will provide new insights into the understanding of new brain treatments from the perspective of stem cell technology especially regarding regenerative medicine and tissue engineering.

Human Co-culture Model of Neurons and Astrocytes to Test Acute Cytotoxicity of Neurotoxic Compounds

Alternative methods and their use in planning and conducting toxicology experiments have become essential for modern toxicologists, thus reducing or replacing living animals. Although in vitro human co-culture models allow the establishment of biologically relevant cell-cell interactions that recapitulate the tissue microenvironment and better mimic its physiology, the number of publications is limited specifically addressing this scientific area and utilizing this test method which could provide an additional valuable model in toxicological studies. In the present study, an in vitro model based on central nervous system (CNS) cell co-cultures was implemented using a transwell system combining human neuronal cells (SH-SY5Y cell line) and glial cells, namely astrocytes (D384 cell line), to investigate neuroprotection of D384 on SH-SY5Y and vice versa. The model was applied to test acute (24-48 hours) cytotoxicity of 3 different neurotoxicants: (1) methyl mercury (1-2.5 μM), (2) Fe₃O₄ nanoparticles (1-100 μg/mL), and (3) methylglyoxal (0.5-1 mM). Data were compared to mono-cultures evaluating the mitochondrial function and cell morphology. The results clearly showed that all compounds tested affected the mitochondrial activity and cell morphology in both mono-culture and co-culture conditions. However, astrocytes, when cultured together with neurons, diminish the neurotoxicant-induced cytotoxic effects that occurred in neurons cultured alone, and astrocytes become more resistant in the presence of neurons. This human CNS co-culture system seems a suitable cell model to feed high-throughput acute screening platforms and to evaluate both human neuronal and astrocytic toxicity and neuroprotective effects of new and emerging materials (eg, nanomaterials) and new products with improved sensitivity due to the functional neuron-astrocyte metabolic interactions.

A drop array culture for patterning adherent mouse embryonic stem cell-derived neurospheres

New therapeutic approaches for repairing an injured or degenerating nervous system have accelerated the development of methods to generate populations of neurons derived from various stem cell sources efficiently. Many of these methods require the generation of neurospheres. Here a simple technique is described for creating an array of adherent mouse embryonic stem cell (mESC)-derived neurospheres using a conventional plastic culture dish and a patterning template. mESC-derived neurospheres are confined to circular (4-mm diameter), gel-coated regions within an array. The adherent neurosphere arrays require 3 days to prepare from an mESC source; they can be maintained in 15 μl drops of medium, and exhibit extensive neurite elaboration after 8 days of cultivation. Additionally, the potential of treating the adherent neurospheres in selected drops of an array is demonstrated with a variety of differentiation-inducing reagents and subsequently individually analysing such neurospheres for gene expression, protein levels and morphological development. Copyright © 2016 John Wiley & Sons, Ltd.