Skip to main content
2023 BMES Annual Meeting Main banner
Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.
Back

    Biomechanics

    (D-151) Mechanical and Structural Properties of Porcine Dura Mater

    Friday, October 13, 2023
    3:30 PM – 4:30 PM PDT
    Location: Exhibit Hall - Row D - Poster # 151
    Introduction:: Approximately 1.4 million people suffer from traumatic brain injury each year, with the number continuing to grow. Cranial dura mater plays a large role in protecting the brain (Sun, et al., 2018). Dura mater is a thin membrane attached to the inner surface of the skull and is composed primarily of collagen fibers. If an injury occurs to the brain, the dura may become damaged, leading to further complications such as stroke, or possible tumor formation. Dura is critical to brain health and finding a replacement material mimicking the structural and mechanical properties of the cranial dura can be challenging. There is a lack of information regarding the structure and mechanical properties of different regions of cranial dura. Understanding the structure-function relationships in regions of the dura may lead to a more realistic dura graft replacement, based on the properties of each area of interest.

    Materials and Methods:: Cranial dura was extracted from a fresh porcine head and then sectioned into the posterior, medial, lateral, and posterior-lateral sections of the left hemisphere of a porcine dura. Immediately, each area of interest was sectioned into n=20, 40 um thick sections using a cryostat. Following sectioning, the dura samples were stained using H&E staining, for identifying the structure and orientation of the collagen fibers. ImageJ software was used to quantify the differences between the regional anisotropy, and tortuosity of the fibers in each section of the dura. Following the analysis of the dura structure, mechanical testing was performed using a Bruker atomic force microscope (AFM) using a quadratic pyramid tip. An AFM model was chosen over other tensile tests due to its ability to capture the varying structure throughout the dura samples. Tensile tests focus on homogenous structures, while it was found that dura mater is not homogenous, therefore, an AFM model was chosen to show more conclusive results. Measurements of Young’s modulus were obtained on 50 um thick samples within each location.

    Results, Conclusions, and Discussions:: Based on image analysis, the medial section of the dura had the highest fiber anisotropy, with an average of 0.28 ± 0.10, and the lowest tortuosity, with an average of 1.11 ± 0.14. The posterior-lateral section of the dura had a similar anisotropy to the medial section, with an average of 0.27 ± 0.07, while having the highest tortuosity, with an average of 1.12 ± 0.17. The lateral section showed an average anisotropy of 0.19 ± 0.08 and an average tortuosity of 1.11 ± 0.11. The posterior section showed an average anisotropy of 0.20 ± 0.06 and an average tortuosity of 1.22 ± 0.17.  Based on AFM testing, the posterior section showed an average Young’s modulus of 175 KPa ± 110 KPa, while the lateral section showed an average of 67 KPa ± 45 Kpa. AFM data is still in the process of being collected and analyzed for medial and posterior-lateral sections. Based on these findings, the collagen fibers in the medial and posterior-lateral sections have the most order. Both sections were extracted from the internal dura, while the posterior and lateral sections were extracted closer to the exterior dura, indicating that collagen fibers towards the center of the dura have more order. This could be attributed to the fact that the internal dura tissue is thinner than the external tissue, indicating that it would need more strength and order to be equivalent to the thicker, outer surfaces. In correlation with the current AFM data, the lateral section showed a low anisotropy, as well as a low Young’s Modulus, indicating that less order correlates to a lower stiffness. Due to the varying moduli and fiber architecture throughout the dura, these results may be used to further develop functional dura grafts based on location of injury, unlike current commercial grafts which do not include the structural differences across the dura.

    Acknowledgements (Optional): :

    References (Optional): :

    Sun, H., Wang, H., Diao, Y., Tu, Y., Li, X., Zhao, W., . . . Zhang, S. (2018). Large retrospective study of artificial dura substitute in patients with traumatic brain injury undergo decompressive craniectomy. Brain and Behavior.