Interactions of Neurons with Physical Environments

Abstract

Nerve growth strongly relies on multiple chemical and physical signals throughout development and regeneration. Currently, a cure for injured neuronal tissue is an unmet need. Recent advances in fabrication technologies and materials led to the development of synthetic interfaces for neurons. Such engineered platforms that come in 2D and 3D forms can mimic the native extracellular environment and create a deeper understanding of neuronal growth mechanisms, and ultimately advance the development of potential therapies for neuronal regeneration. This progress report aims to present a comprehensive discussion of this field, focusing on physical feature design and fabrication with additional information about considerations of chemical modifications. We review studies of platforms generated with a range of topographies, from micro-scale features down to topographical elements at the nanoscale that demonstrate effective interactions with neuronal cells. Fabrication methods are discussed as well as their biological outcomes. This report highlights the interplay between neuronal systems and the important roles played by topography on neuronal differentiation, outgrowth, and development. The influence of substrate structures on different neuronal cells and parameters including cell fate, outgrowth, intracellular remodeling, gene expression and activity is discussed. Matching these effects to specific needs may lead to the emergence of clinical solutions for patients suffering from neuronal injuries or brain-machine interface (BMI) applications.

Neuroprotective Effect of Cannabidiol Against Hydrogen Peroxide in Hippocampal Neuron Culture

“…19 H 2 O 2 has been used as a model molecule to study oxidative stress-induced neural death and also to screen neuroprotective agents on the cultured neurons. 16,[20][21][22][23][24][25] As our on-going research program on neurochemistry and neurophysiology, [26][27][28][29][30][31] this study investigates the neuroprotective effect of CBD against H 2 O 2 in the hippocampal neuron culture.…”

Large-scale acoustic-driven neuronal patterning and directed outgrowth

“…Since the directionality of neuronal outgrowth is strongly affected by the ability of the growth cone at the tip of the growing process to measure chemical cues [80][81][82] , our observation suggests that the directionality is governed by chemical signals released by neighboring www.nature.com/scientificreports www.nature.com/scientificreports/ clusters. Physical environmental cues 60,61,64 such as the orientation of fibers in the gel, can also affect neuronal outgrowth 62,63 . However, to prevent any directionality of the gel fibers, which may affect the neuronal growth, we applied the BAWs only after the gel had been solidified and we have not found any preferred orientation.…”

“…During network formation, neurons transmit information over long distances via their axonal trees. Neuronal processes are elongated in response to orchestrated chemical and physical signals from their environment [55][56][57][58][59][60][61][62][63][64] . Therefore, network patterning and neuronal clustering influence their interconnections, activity, and growth patterns [65][66][67] .…”

Astrocyte‐Encapsulated Hydrogel Microfibers Enhance Neuronal Circuit Generation

“…The substantial intercellular separation between astrocytes and neurons might disturb the bidirectional diffusions of nutrients, trophic factors and others, leading to inefficiency in the neurosupportive effects of astrocytes . Moreover, bulk hydrogels do not provide topographical effects to neurons, which are important for neuronal development . In this work, we propose an astrocyte‐encapsulated, cytoprotective hydrogel microfiber for neuronal survival and physiology, which retains the trophic and chemically supportive functions of astrocytes, while reducing astrocyte migration, inhibiting inflammation problem, and increasing tissue integrity.…”