Compressive Mechanical Characterization of Non-Human Primate Spinal Cord White Matter

Resource type
Date created
2018-07-01
Authors/Contributors
Abstract
The goal of developing computational models of spinal cord injury (SCI) is to better understand the human injury condition. However, finite element models of human SCI have used rodent spinal cord tissue properties due to a lack of experimental data. Central nervous system tissues in non human primates (NHP) closely resemble that of humans and therefore, it is expected that material constitutive models obtained from NHPs will increase the fidelity and the accuracy of human SCI models. Human SCI most often results from compressive loading and spinal cord white matter properties affect FE predicted patterns of injury; therefore, the objectives of this study were to characterize the unconfined compressive response of NHP spinal cord white matter and present an experimentally derived, finite element tractable constitutive model for the tissue. Cervical spinal cords were harvested from nine male adult NHPs (Macaca mulatta). White matter biopsy samples (3 mm in diameter) were taken from both lateral columns of the spinal cord and were divided into four strain rate groups for unconfined dynamic compression and stress relaxation (post-mortem <1-hour). The NHP spinal cord white matter compressive response was sensitive to strain rate and showed substantial stress relaxation confirming the viscoelastic behavior of the material. An Ogden 1st order model best captured the non-linear behavior of NHP white matter in a quasi-linear viscoelastic material model with 4-term Prony series. This study is the first to characterize NHP spinal cord white matter at high (>10/sec) strain rates typical of traumatic injury. The finite element derived material constitutive model of this study will increase the fidelity of SCI computational models and provide important insights for transferring pre-clinical findings to clinical treatments.
Document
Identifier
DOI: 10.1016/j.actbio.2018.05.002
Published as
Jannesar, S., Allen, M., Mills, S., Gibbons, A., Bresnahan, J. C., Salegio, E. A., & Sparrey, C. J. (2018). Compressive mechanical characterization of non-human primate spinal cord white matter. Acta Biomaterialia, 74, 260–269. https://doi.org/10.1016/j.actbio.2018.05.002.
Publication title
Acta Biomaterialia
Document title
Compressive Mechanical Characterization of Non-Human Primate Spinal Cord White Matter
Date
2018
Volume
74
First page
260
Last page
269
Publisher DOI
10.1016/j.actbio.2018.05.002
Copyright statement
Copyright is held by the author(s).
Scholarly level
Peer reviewed?
Yes
Language
Member of collection
Attachment Size
manuscript_tissue_mech_paper.pdf 868.2 KB