Engineering a High Throughput Axon Injury System

Abstract

Several key biological mechanisms of traumatic injury to axons have been elucidated using in vitro stretch injury models. These models, however, are based on the experimentation of single cultures keeping productivity slow. Indeed, low yield has hindered important and well-founded investigations requiring high throughput methods such as proteomic analyses. To meet this need, we engineered a multi-well high throughput injury device to accelerate and accommodate the next generation of traumatic brain injury research. This modular system stretch injures neuronal cultures in either a 24-well culture plate format or 6 individual wells simultaneously. Custom software control allows the user to accurately program the pressure pulse parameters to achieve the desired substrate deformation and injury parameters. Analysis of the pressure waveforms showed that peak pressure was linearly related to input pressure and valve open times and that the 6- and 24-well modules displayed rise times, peak pressures, and decays with extremely small standard deviations. Data also confirmed that the pressure pulse was distributed evenly throughout the pressure chambers and therefore to each injury well. Importantly, the relationship between substrate deformation and applied pressure was consistent among the multiple wells and displayed a predictable linear behavior in each module. These data confirm that this multi-well system performs as well as currently used stretch injury devices and can undertake high throughput studies that are needed across the field of neurotrauma research.

Therapy Development for Diffuse Axonal Injury

“…99 Moreover, a multi-well system of in vitro TAI has recently been developed that may further expand the capacity for therapy evaluation and development. 100 Because the clinical relevance of in vitro screening systems for TAI therapies has not been established, however, it will be important to run initial studies in coordinated parallel efforts with small and large animal models.…”

High Ca2+ Influx During Traumatic Brain Injury Leads to Caspase-1-Dependent Neuroinflammation and Cell Death

“…Mature IL-1β has been linked to many immune reactions including the recruitment of inflammatory cells to the site of infection [19]. In this study, we utilized a neuronal stretch injury model [20] to visualize in real time the activation of caspase-1 enzyme and the subsequent induction of apoptosis. The results obtained in the neuronal stretch injury were then validated in the fluid percussion injury (FPI) model in vivo [21][22][23][24].…”

Fluid percussion injury device for the precise control of injury parameters

“…peak pressure in the fluid percussion model) to severity in terms of brain pathology and behavioral outcomes. The contributions that the temporal characteristics of the injury such as rise time and duration have on damage to the brain have just begun to be investigated (Cater et al, 2005;Magou et al, 2011;Ganpule et al, 2013;Sundaramurthy et al, 2012).…”

“…It is used to deform the brain of rodents to produce both focal and diffuse injury characteristics (Cortez et al, 1989;Dixon et al, 1987;Graham et al, 2000;Hicks et al, 1996;Morales et al, 2005;Thompson et al, 2005). Potentially, one of the biggest contributors to differences in TBI outcome could be the rate at which pressure changes in addition to magnitude of pressure that deforms the brain (Magou et al, 2011;Ganpule et al, 2013;Sundaramurthy et al, 2012). The term "rate" is defined as the rise time to peak pressure.…”

“…The term "rate" is defined as the rise time to peak pressure. Because brain tissue is viscoelastic, both rate and magnitude of the pressure will affect how the tissue responds mechanically and thus could lead to unique pathophysiologies (Magou et al, 2011;Shuck and Advani, 1972;Arbogast et al, 1997). Greatly contrasting examples would be a head impact from a fall vs. a blast wave; the latter being several order of magnitude higher in rate.…”