# Uniaxial tensile material properties of adult Chinese dura mater: investigating the influence of age, sex, and anatomical site

## TL;DR

This study examines how age, anatomical region, and loading direction affect the mechanical properties of the dura mater in Chinese adults, providing data for more accurate brain injury models.

## Contribution

The study provides population-specific biomechanical data for Chinese adults' dura mater, highlighting age-related degradation and anisotropic behavior.

## Key findings

- Elastic modulus and failure properties of dura mater significantly decrease with age.
- Dura mater shows anisotropic behavior with higher mechanical properties in the sagittal direction.
- No significant sex-based differences were found in dura mater properties.

## Abstract

This study investigated the biomechanical properties of the dura mater from 29 Chinese adult donors (20 -86 years), focused on the influence of age, anatomical region, sex and loading direction, to establish Chinese population - specific material parameters for cranial finite element (FE) models and enhance forensic traumatic brain injury analysis.

In this study, a total of 275 dural specimens were prepared and categorized into young adult (20-44 years), middle aged (45-64 years), and elderly (≥65 years) cohorts. Samples were excised from frontal, temporal, parietal and occipital regions and tested uniaxially in sagittal and coronal directions, with strain measured via digital image correlation (DIC) techniques. True stress-strain curves were fitted to the Raghavan model to determine elastic fiber modulus (EE
), collagen fiber modulus (EC
), failure stress (σTf
), and failure strain (εTf
); ultimate tensile force (MaxForce) was also recorded. Histological analysis assessed age-related microstructural changes.

indicated significant age-related degradation: EC
, σTf
, εTf
; and MaxForce significantly decreased with age (median EC
declined from 28.0 MPa in young adults to 15.3 MPa in the elderly, P < 0.05; median εTf
from 0.215 to 0.156, P < 0.05), while EE
showed no significant age correlation (P = 0.10). Significant regional variance were observed, with the parietal region exhibiting higher EE
(P = 0.01) and σTf
(P = 0.03) compared to the occipital region; εTf
showed no significant regional differences (P = 0.12). Dura mater demonstrated clear anisotropy: sagittal loading yielded significantly higher median EC
(27.0 MPa vs. 18.1 MPa coronal, P = 0.003), σTf
(4.30 MPa vs. 3.18 MPa coronal, P = 0.020), and MaxForce (12.9 N vs. 10.3 N coronal, P = 0.014). No statistically significant sex-based differences were found for any parameter (P > 0.05). Histology confirmed progressive age-related collagen disorganization and elastic fiber degradation. In conclusion, Chinese adult dura mater exhibits significant age-dependent decline in mechanical integrity, clear anisotropy favoring the sagittal direction, and notable regional heterogeneity, but no significant sex-based differences.

These findings provide crucial, population-specific data for improving the biofidelity of FE head models and forensic injury analysis.