Visco-hyperelastic characterization of human brain white matter micro-level constituents in different strain rates

Ramzanpour, Mohammadreza; Hosseini-Farid, Mohammad; McLean, Jayse; Ziejewski, Mariusz; Karami, G.

doi:10.1007/s11517-020-02228-3

Cited by 22 publications

(12 citation statements)

References 49 publications

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“…Recent efforts towards micromechanical modeling of brain tissue have proposed to include the individual contributions of axons and extracellular matrix in white matter tissue [25,42] or the brain stem [2,26] through representative volume elements accounting for the distribution and orientation of nerve fiber bundles from magnetic resonance and diffusion tensor imaging data. However, it remains controversial whether axons indeed majorly contribute to the mechanical response of brain tissue [12,15,20,51] and such models would only be valid for certain white matter areas.…”

Section: Introductionmentioning

confidence: 99%

Insights into the Microstructural Origin of Brain Viscoelasticity

Reiter

Roy

Paulsen

et al. 2021

J Elast

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Mechanical aspects play an important role in brain development, function, and disease. Therefore, continuum-mechanics-based computational models are a valuable tool to advance our understanding of mechanics-related physiological and pathological processes in the brain. Currently, mainly phenomenological material models are used to predict the behavior of brain tissue numerically. The model parameters often lack physical interpretation and only provide adequate estimates for brain regions which have a similar microstructure and age as those used for calibration. These issues can be overcome by establishing advanced constitutive models that are microstructurally motivated and account for regional heterogeneities through microstructural parameters.In this work, we perform simultaneous compressive mechanical loadings and microstructural analyses of porcine brain tissue to identify the microstructural mechanisms that underlie the macroscopic nonlinear and time-dependent mechanical response. Based on experimental insights into the link between macroscopic mechanics and cellular rearrangements, we propose a microstructure-informed finite viscoelastic constitutive model for brain tissue. We determine a relaxation time constant from cellular displacement curves and introduce hyperelastic model parameters as linear functions of the cell density, as determined through histological staining of the tested samples. The model is calibrated using a combination of cyclic loadings and stress relaxation experiments in compression. The presented considerations constitute an important step towards microstructure-based viscoelastic constitutive models for brain tissue, which may eventually allow us to capture regional material heterogeneities and predict how microstructural changes during development, aging, and disease affect macroscopic tissue mechanics.

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Section: Introductionmentioning

confidence: 99%

Insights into the Microstructural Origin of Brain Viscoelasticity

Reiter

Roy

Paulsen

et al. 2021

J Elast

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“…While the meninges could be possibly modeled as a viscous fluid with the material properties of water ( Singh et al, 2014 ), we do not expect such properties to significantly modify the simulated pressure-time profiles because other studies that approximated the meninges using the Mie-Gruneisen equation of state for water observed oscillations in the model-predicted ICP for blast-loading conditions ( Garimella et al, 2018 ; Tong et al, 2019 ). Finally, we assumed homogeneous properties for the brain tissue and necessarily excluded rate-dependent material properties specific to brain white matter ( Tse et al, 2017 ; Ramzanpour et al, 2020 ), which could possibly influence VMS and MPS values. Nonetheless, as the redistribution of MPS resulting from the inclusion of vasculature is consistent for homogeneous and heterogeneous brain-tissue properties ( Zhao and Ji, 2020 ; Subramaniam et al, 2021 ), we expect our overall findings to remain valid.…”

Section: Discussionmentioning

confidence: 99%

Cerebral Vasculature Influences Blast-Induced Biomechanical Responses of Human Brain Tissue

Subramaniam

Unnikrishnan

Sundaramurthy

et al. 2021

Front. Bioeng. Biotechnol.

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Multiple finite-element (FE) models to predict the biomechanical responses in the human brain resulting from the interaction with blast waves have established the importance of including the brain-surface convolutions, the major cerebral veins, and using non-linear brain-tissue properties to improve model accuracy. We hypothesize that inclusion of a more detailed network of cerebral veins and arteries can further enhance the model-predicted biomechanical responses and help identify correlates of blast-induced brain injury. To more comprehensively capture the biomechanical responses of human brain tissues to blast-wave exposure, we coupled a three-dimensional (3-D) detailed-vasculature human-head FE model, previously validated for blunt impact, with a 3-D shock-tube FE model. Using the coupled model, we computed the biomechanical responses of a human head facing an incoming blast wave for blast overpressures (BOPs) equivalent to 68, 83, and 104 kPa. We validated our FE model, which includes the detailed network of cerebral veins and arteries, the gyri and the sulci, and hyper-viscoelastic brain-tissue properties, by comparing the model-predicted intracranial pressure (ICP) values with previously collected data from shock-tube experiments performed on cadaver heads. In addition, to quantify the influence of including a more comprehensive network of brain vessels, we compared the biomechanical responses of our detailed-vasculature model with those of a reduced-vasculature model and a no-vasculature model for the same blast-loading conditions. For the three BOPs, the predicted ICP values matched well with the experimental results in the frontal lobe, with peak-pressure differences of 4–11% and phase-shift differences of 9–13%. As expected, incorporating the detailed cerebral vasculature did not influence the ICP, however, it redistributed the peak brain-tissue strains by as much as 30% and yielded peak strain differences of up to 7%. When compared to existing reduced-vasculature FE models that only include the major cerebral veins, our high-fidelity model redistributed the brain-tissue strains in most of the brain, highlighting the importance of including a detailed cerebral vessel network in human-head FE models to more comprehensively account for the biomechanical responses induced by blast exposure.

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“…Furthermore, Rohner et al [193], reported 14.1% generation of new bone in a pig model after three months, using PCL scaffolds prepared by FDM and coated with bone marrow. Several clinical studies have also shown that PCL scaffolds manufactured by FDM have favorable biocompatibility and a low cost of manufacturing, leading to approval by the US Food and Drug Administration for use in human bone tissue [194][195][196][197]. Currently commercialized products manufactured by FDM include Osteoplug™ and Osteomesh™ (Osteopore), which are thin interwoven meshes and three-dimensional implants respectively as it can be seen in Figure 9.…”

Section: Fused Deposition Modeling (Fdm)mentioning

confidence: 99%

Additive Manufacturing Techniques for Fabrication of Bone Scaffolds for Tissue Engineering Applications

Jahani¹,

Wang²,

Brooks³

2020

RPM

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Bone tissue engineering (BTE) as a modern and more effective treatment for bone defects has recently received lots of attention. One of the pivotal parts of BTE is the "scaffold", which functions as an indwelling carrier of cells and additives, as well as, providing a foundation for cell growth and eventually forming new, native-like bone. Up to now, many methods and materials have been employed to manufacture bone scaffolds. This review focuses on providing both basic knowledge of BTE as well as possible methods of scaffold manufacturing. We categorize the fabrication methods into; current conventional methods and newly emerging additive manufacturing (AM) techniques. The fundamental, capabilities and limitations of each technique is investigated, and the latest achievements are presented.

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Visco-hyperelastic characterization of human brain white matter micro-level constituents in different strain rates

Cited by 22 publications

References 49 publications

Insights into the Microstructural Origin of Brain Viscoelasticity

Insights into the Microstructural Origin of Brain Viscoelasticity

Cerebral Vasculature Influences Blast-Induced Biomechanical Responses of Human Brain Tissue

Additive Manufacturing Techniques for Fabrication of Bone Scaffolds for Tissue Engineering Applications

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