School of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130025, PR China; Key Laboratory of CNC Equipment Reliability, Ministry of Education, Jilin University, 5988 Renmin Street, Changchun, 130025, PR China.
School of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130025, PR China; Key Laboratory of Bionic Engineering, Ministry of Education, Jilin University, Changchun, 130025, PR China.
J Mech Behav Biomed Mater. 2022 Feb;126:104924. doi: 10.1016/j.jmbbm.2021.104924. Epub 2021 Dec 18.
Research on the mechanical properties of brain tissue has gradually deepened recently. Two indentation protocols were used here to characterize the mechanical properties of cortical tissues. Further, histological staining was used to explore the correlation between the mechanical properties and microstructure on the basis of the density of cell nuclei and proteoglycan content. No significant difference was observed in transient contact stiffness between the cerebral cortex and cerebellar cortex at the depth interval of 0-600 μm under the cortical surface; however, the average shear modulus of the cerebral cortex was higher than that of the cerebellar cortex. The cerebral cortex responded more quickly to the change in load and released stress more thoroughly than the cerebellar cortex. In addition, the density of cell nuclei was related to both the transient contact stiffness and second time constant of cortical tissues. Proteoglycan content had a more significant impact on the shear modulus, second time constant, and stress relaxation rate of cortical tissues. Exploring mechanical properties thoroughly will provide more detailed mechanical information for future brain chip implantation. Alternatively, linking the mechanical properties of cortical tissues to the microstructure can provide basic data for the design and manufacture of substitute materials for brain tissue.
近年来，人们对脑组织的力学性能研究逐渐深入。本研究采用两种压痕技术来描述皮质组织的力学性能。进一步地，基于细胞核密度和蛋白聚糖含量，通过组织学染色来探讨力学性能与微观结构之间的相关性。在皮质表面下 0-600μm 的深度间隔内，大脑皮质和小脑皮质的瞬态接触刚度没有显著差异；然而，大脑皮质的平均剪切模量高于小脑皮质。大脑皮质对负荷变化的响应速度比小脑皮质更快，释放应力也更彻底。此外，细胞核密度与皮质组织的瞬态接触刚度和第二时间常数均有关。蛋白聚糖含量对皮质组织的剪切模量、第二时间常数和应力松弛率有更显著的影响。深入探索力学性能可以为未来的脑芯片植入提供更详细的力学信息。或者，将皮质组织的力学性能与微观结构联系起来，可以为脑组织替代材料的设计和制造提供基础数据。
