Determining a Failure Strain Envelope for Neurons in Uniaxial Compression
Jonathan Estrada (Brown University), Eyal Bar-Kochba (Brown University), Christian Franck (Brown University)
Soft Materials and Structures
Tue 9:00 - 10:30
Barus-Holley 158
Traumatic Brain Injury (TBI), usually the result of impact or blast to the head, affects about 1.5 million Americans annually [1]. Though studies have investigated viability of neurons after different strains in culture in 3D systems [2], uniaxial deformation and individual, mechanical cell response has largely remained unstudied. We have built a custom impact device using a Linear Voice Coil Actuator to mechanically deform rat cortical neurons seeded in collagen (=0.06) matrices and have shown, using Digital Volume Correlation (DVC) [3], that neurons experience uniaxial compression in a region of interest. Neurons labeled with Calcein Red-Orange and Fluo-4 (Invitrogen) are imaged pre- and post-impact using confocal microscopy. Morphology is recorded in 3D, rendered using a rayburst algorithm [4], and smoothened by the Laplacian method. Strains are then calculated on the initial rendering for later points of injury and compiled into a failure strain envelope. Future work includes varying strains and strain rates. [1] DeKosky, S., Ikonomovic, M., Gandy, S. New England Journal of Medicine, 2010. [2] Morrison, B., Elkin, B. S., Dollé, J.-P., & Yarmush, M. L. (2011). In vitro models of traumatic brain injury. Annual Review of Biomedical Engineering (Vol. 13, pp. 91–126). doi:10.1146/annurev-bioeng-071910-124706 [3] Franck, C., Maskarinec, S.A., Ravichandran, C., Tirrell, D.A., “Depth Perception: Quantifying Cellular Traction Forces in Three Dimensions,” PNAS, 106:22108 - 22113, 2009. [4] Rodriguez, A., Ehlenberger, D. B., Hof, P. R., & Wearne, S. L. (2006). Rayburst sampling, an algorithm for automated three-dimensional shape analysis from laser scanning microscopy images. Nature protocols, 1(4), 2152–61. doi:10.1038/nprot.2006.313