Two and Three-Dimensional in Vitro Models of Blast-Induced Neurotrauma

Blast-induced neurotrauma (BINT) has become an increasingly significant concern in Veterans returning from warfare. Associated brain injury and cognitive deficits are difficult to diagnose as the nature of this injury is progressive. In order to better understand the mechanisms of BINT at the microscopic level, two- and three-dimensional models of astrocytes were studied. The 3-D model was developed using Matrigel® to embed the cells. Injury was induced by exposure to an overpressure of 20 psi (140 kPa) using a shock wave generator which simulates a free field blast profile. Cellular viability was measured by MTT assays conducted at 24 and 48 hours post-blast. Gene expression levels of glial-fibrillary acidic protein (GFAP), ß-actin, and vinculin were analyzed as potential structural biomarkers of injury at 48 and 72 hours post-blast. Results indicated that glial cells survived and became activated by 72 hours following exposure. Specifically, gene expression of GFAP was elevated in simulated blast cultures as compared to controls. Moreover, 2- and 3-D cultures were observed to have different time periods of activation. These activation markers may be useful when designing therapeutic targets to mitigate injury progression.