Compressive mechanical characterization of non-human primate spinal cord white matter
| Autor: | Jacqueline C. Bresnahan, Shervin Jannesar, Sarah Mills, Carolyn J. Sparrey, Anne M. Gibbons, Mark Allen, Ernesto A. Salegio |
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| Rok vydání: | 2018 |
| Předmět: |
Compressive Strength
Finite Element Analysis Models Neurological 0206 medical engineering Central nervous system Biomedical Engineering Strain (injury) 02 engineering and technology Biology Biochemistry Biomaterials White matter 03 medical and health sciences 0302 clinical medicine medicine Animals Humans Molecular Biology Spinal cord injury Non human primate Spinal cord white matter General Medicine Anatomy medicine.disease Spinal cord Macaca mulatta White Matter 020601 biomedical engineering Elasticity medicine.anatomical_structure Traumatic injury Stress Mechanical 030217 neurology & neurosurgery Biotechnology |
| Zdroj: | Acta Biomaterialia. 74:260-269 |
| ISSN: | 1742-7061 |
| DOI: | 10.1016/j.actbio.2018.05.002 |
| Popis: | 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-mortem1-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.Spinal cord injury (SCI) finite element (FE) models provide an important tool to bridge the gap between animal studies and human injury, assess injury prevention technologies (e.g. helmets, seatbelts), and provide insight into the mechanisms of injury. Although, FE model outcomes depend on the assumed material constitutive model, there is limited experimental data for fresh spinal cords and all was obtained from rodent, porcine or bovine tissues. Central nervous system tissues in non human primates (NHP) more closely resemble humans. This study characterizes fresh NHP spinal cord material properties at high strains rates and large deformations typical of SCI for the first time. A constitutive model was defined that can be readily implemented in finite strain FE analysis of SCI. |
| Databáze: | OpenAIRE |
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