Development of a P(L-D,L)LA Foam as a Dura Substitute and Its In Vitro Evaluation

Abstract

Dura substitutes are used to reduce the risk of postoperative complications following neurosurgical interventions, and to facilitate the healing of dura damages or defects caused by injuries. Traditional tissue transplants have limitations like limited tissue availability, potential risk of immune rejection and disease transmission. The use of biomaterials composed of synthetic polymers as dura substitutes offers a promising approach to overcome these limitations to replace and treat damaged dura mater. Potential biocompatible porous scaffolds still need to be developed to minimize the risks of immune response and disease transmission, while also ensuring effective cell migration and cell ingrowth in three dimension. The aim of the present study was to develop a poly(L-lactide-co-D,L-lactide) (P(L-D,L)LA) foam with an optimal pore size for dura mater substitution, investigate its morphological characteristics, and evaluate its potential for dura mater regeneration by assessing the spreading and growth of meningeal cells within it through in vitro studies. Foams were produced by lyophilization using different concentrations of P(L-D,L)LA solution. A GMP-grade P(L-D,L)LA, suitable for medical device applications, was used in this study. Morphological analysis was performed using scanning electron microscopy, and porosity of the foams was studied with mercury porosimetry. In in vitro studies, meningeal cells were seeded onto the polymeric foams, and their behavior and proliferation in these scaffolds were investigated with cytoskeleton and nucleus staining, and colorimetric cell proliferation assay, respectively. Scanning electron microscopy results showed that the foams prepared with 2.5% and 3% polymer solutions displayed good structural integrity and convenient interconnectivity, with pore sizes ranging from 80 to 150 µm. However, the foams prepared with 2% and 4% polymer solution demonstrated poor structural integrity and low interconnectivity, respectively. In vitro studies showed that the foams prepared with 2.5% and 3% polymer solutions served effectively as scaffolds for meningeal cells, and the cells attached, spread and homogeneously distributed. In addition, the cells proliferated and increased in number over time within these polymeric scaffolds. These findings suggest that the foams produced with 2.5% and especially 3% P(L-D,L)LA polymer solutions could effectively serve as a suitable substitute for the dura mater, providing an appropriate environment for cell ingrowth and tissue integration. This indicates that the developed foam could be a promising treatment for dura mater damage or defects, with the potential approach to promote regeneration in future in vivo and clinical studies.

Keywords

• Dura Substitute
• Synthetic Polymer
• Porous Foam
• Meningeal Cells
• Cell Ingrowth

References

1. Cho, M., Shim, K. M., Park, S. S., Kang, S. S., Jang, K., & Kim, S. E. (2024). Evaluation of Biocompatibility and Healing Properties of Dural Substitutes Produced by Electrospinning Technology. In Vivo, 38(3), 1119-1126. https://doi.org/10.21873/invivo.13546
2. Choi, S.-W., Zhang, Y., & Xia, Y. (2010) Three-dimensional scaffolds for tissue engineering: the importance of uniformity in pore size and structure. Langmuir, 26(24), 19001-19006. https://doi.org/10.1021/la104206h
3. Deng, K., Yang, Y., Ke, Y., Luo, C., Liu, M., Deng, Y., Tian, Q., Yuan, Y., Yuan, T., & Xu, T. (2017). A novel biomimetic composite substitute of PLLA/gelatin nanofiber membrane for dura repairing. Neurological Research, 39(9), 819-829. https://doi.org/10.1080/01616412.2017.1348680
4. Deng, W., Tan, Y., Riaz Rajoka, M. S., Xue, Q., Zhao, L., & Wu, Y. (2021). A new type of bilayer dural substitute candidate made up of modified chitin and bacterial cellulose. Carbohydrate Polymers, 256, 117577. http://www.doi.org/10.1016/j.carbpol.2020.117577
5. Dong, R.-P., Zhang, Q., Yang, L.-L., Cheng, X.-L., & Zhao, J.-W. (2023). Clinical management of dural defects: A review. World Journal of Clinical Cases, 11(13), 2903-2915. http://www.doi.org/10.12998/wjcc.v11.i13.2903
6. Guimarães, A., Martins, A., Pinho, E. D., Faria, S., Reis, R. L., & Neves, N. M. (2010). Solving cell infiltration limitations of electrospun nanofiber meshes for tissue engineering applications. Nanomedicine (Lond), 5(4), 539-554. https://doi.org/10.2217/nnm.10.31
7. Kenar, H., Kose, G. T., & Hasirci, V. (2010). Design of a 3D aligned myocardial tissue construct from biodegradable polyesters. Journal of Materials Science: Materials in Medicine, 21(3), 989-997. https://doi.org/10.1007/s10856-009-3917-8
8. Khurana, D., Suresh, A., Nayak, R., Shetty, M., Sarda, R. K., Knowles, J. C., Kim, H.-W., Singh, R. K., & Singh, B. N. (2024). Biosubstitutes for dural closure: Unveiling research, application, and future prospects of dura mater alternatives. Journal of Tissue Engineering, 15, 1-26. http://www.doi.org/10.1177/20417314241228118

9. Klopp, L. S., Welch, W. C., Tai, J. W., Toth, J. M., Cornwall, G. B., & Turner, A. S. (2004). Use of polylactide resorbable film as a barrier to postoperative peridural adhesion in an ovine dorsal laminectomy model. Neurosurgical Focus, 16(3), 1-9. http://www.doi.org/10.3171/foc.2004.16.3.3
10. Laun, A., Tonn, J. C., & Jerusalem, C. (1990). Comparative study of lyophilized human Dura mater and lyophilized bovine pericardium as dural substitutes in neurosurgery. Acta Neurochirurgica (Wien), 107(1-2), 16–21. http://www.doi.org/10.1007/BF01402607
11. Li, Q., Mu, L., Zhang, F., Sun, Y., Chen, Q., Xie, C., & Wang, H. (2017). A novel fish collagen scaffold as dural substitute. Materials Science and Engineering C Materials for Biological Applications, 80, 346-351. http://www.doi.org/10.1016/j.msec.2017.05.102
12. Liao, J., Li, X., He, W., Guo, Q., & Fan, Y. (2021). A biomimetic triple-layered biocomposite with effective multifunction for dura repair. Acta Biomaterialia, 130, 248-267. https://doi.org/10.1016/j.actbio.2021.06.003
13. Liu, W., Wang, X., Su, J., Jiang, Q., Wang, J., Xu, Y., Zheng, Y., Zhong, Z., & Lin, H. (2021). In vivo Evaluation of Fibrous Collagen Dura Substitutes. Frontiers in Bioengineering and Biotechnology, 9, 628129. http://www.doi.org/10.3389/fbioe.2021.628129
14. Mai, R., Osidak, E., Mishina, E., Domogatsky, S., Andreev, A., Dergam, Y., & Popov, V. (2024). Collagen Membrane as Artificial Dura Substitute: A Comprehensive In Vivo Study of Efficiency and Substitution Compared to Durepair. World Neurosurgery, In Press. https://doi.org/10.1016/j.wneu.2024.08.061
15. Mekhail, M., Almazan, G., & Tabrizian, M. (2012). Oligodendrocyte-protection and remyelination post-spinal cord injuries: a review. Progress in Neurobiology, 96(3), 322-239. https://doi.org/10.1016/j.pneurobio.2012.01.008
16. Ohbayashi, N., Inagawa, T., Katoh, Y., Kumano, K., Nagasako, R., & Hada, H. (1994). Complication of silastic dural substitute 20 years after dural plasty. Surgical Neurology, 41(4), 338-341. http://www.doi.org/10.1016/0090-3019(94)90187-2
17. Patel, N., & Kirmi, O. (2009). Anatomy and imaging of the normal meninges. Seminars in Ultrasound, CT and MR, 30(6), 559-564. http://www.doi.org/10.1053/j.sult.2009.08.006
18. Ramot, Y., Kronfeld, N., Steiner, M., Manassa, N. N., Bahar, A., & Nyska, A. (2024) Neural tissue tolerance to synthetic dural mater graft implantation in a rabbit durotomy model. Journal of Toxicologic Pathology, 37(2), 83-91. https://doi.org/10.1293/tox.2023-0121
19. Rnjak-Kovacina, J., Wise, S. G., Li, Z., Maitz, P. K. M., Young, C. J., Wang, Y., & Weiss, A. S. (2011). Tailoring the porosity and pore size of electrospun synthetic human elastin scaffolds for dermal tissue engineering. Biomaterials, 32(28), 6729-6736. http://www.doi.org/10.1016/j.biomaterials.2011.05.065
20. Schachtner, J., Frohbergh, M., Hickok, N., & Kurtz, S. (2019). Are Medical Grade Bioabsorbable Polymers a Viable Material for Fused Filament Fabrication? Journal of Medical Devices, 13(3), 0310081-310085. http://www.doi.org/10.1115/1.4043841
21. Shi, Z., Xu, T., Yuan, Y., Deng, K., Liu, M., Ke, Y., Luo, C., Yuan, T., & Ayyad, A. (2016). A New Absorbable Synthetic Substitute With Biomimetic Design for Dural Tissue Repair. Artifical Organs, 40(4), 403-413. http://www.doi.org/10.1111/aor.12568
22. Shijo, M., Honda, H., Koyama, S., Ishitsuka, K., Maeda, K., Kuroda, J., Tanii, M., Kitazono, T., & Iwaki, T. (2017). Dura mater graft-associated Creutzfeldt-Jakob disease with 30-year incubation period. Neuropathology, 37(3), 275-281. http://www.doi.org/10.1111/neup.12359
23. Wang, M. O., Vorwald, C. E., Dreher, M. L., Mott, E. J., Cheng, M. H., Cinar, A., Mehdizadeh, H., Somo, S., Dean, D., Brey, E. M., & Fisher, J. P. (2015). Evaluating 3D-printed biomaterials as scaffolds for vascularized bone tissue engineering. Advanced Materials, 27(1), 138-144. http://www.doi.org/10.1002/adma.201403943
24. Wang, W., & Ao, Q. (2019). Research and application progress on dural substitutes. Journal of Neurorestoratology, 7(4-5), 161-170. http://www.doi.org/10.26599/JNR.2019.9040020
25. Wang, Y.-f., Guo, H.-f., & Ying, D.-j. (2013). Multilayer scaffold of electrospun PLA-PCL-collagen nanofibers as a dural substitute. Journal of Biomedical Materials Research Part B Applied Biomaterials, 101(8), 1359-1366. http://www.doi.org/10.1002/jbm.b.32953
26. Welch, W. C., Cornwall, G. B., Toth, J. M., Turner, A. S., Thomas, K. A., Gerszten, P. C., & Nemoto, E. M. (2002). Use of polylactide resorbable film as an adhesion barrier. Orthopedics, 25(10), 1121-1130. https://doi.org/10.3928/0147-7447-20021002-02
27. Yucel, D., Kose, G. T., & Hasirci, V. (2010). Tissue engineered, guided nerve tube consisting of aligned neural stem cells and astrocytes. Biomacromolecules, 11(12), 3584-3591. https://doi.org/10.1021/bm1010323