Age‑related changes of the spinal cord: A biomechanical study

Abstract

Although it is known that aging plays an important role in the incidence and progression of cervical spondylotic myelopathy (CSM), the underlying mechanism is unclear. Studies that used fresh bovine cervical spinal cord report the gray matter of the cervical spinal cord as being more rigid and fragile than the white matter. However, there are no reports regarding the association between aging an tensile and Finite Element Method (FEM). Therefore, FEM was used based on the data pertaining to the mechanical features of older bovine cervical spinal cord to explain the pathogenesis of CSM in elderly patients. Tensile tests were conducted for white and gray matter separately in young and old bovine cervical spinal cords, and compared with their respective mechanical features. Based on the data obtained, FEM analysis was further performed, which included static and dynamic factors to describe the internal stress distribution changes of the spinal cord. These results demonstrated that the mechanical strength of young bovine spinal cords is different from that of old bovine spinal cords. The gray matter of the older spinal cord was significantly softer and more resistant to rupture compared with that of younger spinal cords (P<0.05). Among the old, although the gray matter was more fragile than the white matter, it was similar to the white matter in terms of its rigidity (P<0.05). The in vitro data were subjected to three compression patterns. The FEM analysis demonstrated that the stress level rises higher in the old spinal cords in response to similar compression, when compared with young spinal cords. These results demonstrate that in analyzing the response of the spinal cord to compression, the age of patients is an important factor to be considered, in addition to the degree of compression, compression speed and parts of the spinal cord compression factor.

A 3D Printable Electroconductive Biocomposite Bioink Based on Silk Fibroin-Conjugated Graphene Oxide

“…The second factor is the solubility and surface hydrophilicity of SGOB1, which allow even distribution of reduced graphene oxide in the semiconductive SB matrix, thereby assuring an ideal electroconductivity for neuronal differentiation. , Another factor is the role of the mechanical cue in the determination of cell differentiation . A recent investigation of fresh bovine cervical spinal cord mechanical properties put the tensile strength within 60–112 kPa, which is within the range of what we obtained from our novel SGOB1 bioink …”

“…44 A recent investigation of fresh bovine cervical spinal cord mechanical properties put the tensile strength within 60−112 kPa, which is within the range of what we obtained from our novel SGOB1 bioink. 49…”

“…The mechanical properties of hydrogels obtained from SGOB1 bioink are comparable with those of native spinal tissue. 49 Thus, our primary aim of having complex structures of GO copolymers with mechanical cues similar to those of native tissues was achieved. In addition, we are able to improve the solubility of constituent rGO using SF.…”

A New Framework for Investigating the Biological Basis of Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 5]: Mechanical Stress, Vulnerability and Time

“… 17 , 114 Mechanical stress will also be influenced by the different mechanical properties and tolerance of microstructures within the spinal cord, for example, the white vs gray matter, or relative myelin content of spinal cord pathways 115 which are also subject to change, for example, with age and evolution of injury. 50 , 116 …”

“…They demonstrated that changes to both white and gray matter structures increased measured mechanical stress, with changes to the white matter most significant. 153 Okazaki et al 116 (2018) comparing young and old bovine spinal cord specimen demonstrated different tensile and compression stress patterns, in particular, during compression modeling within young specimen, stress was largely confined to white matter structures, whereas in older specimen distributed throughout the spinal cord.…”