Speaker
Description
Borax-based Self-Healing Gels for Meniscus Tissue Engineering
Selma. J. Padilla Padilla1, Pavel Milkin1, Indra Apsite1, Leonid Ionov1,2
1 Faculty of Engineering Sciences, University of Bayreuth, Ludwig Thoma Str. 36A, 95447 Bayreuth, Germany
2Bavarian Polymer Institute, University of Bayreuth, Bayreuth, Germany
The meniscus plays a crucial role in force transmission, shock absorption, joint lubrication, and stabilization of the knee joint. One of the major challenges in meniscus biofabrication lies in replicating its highly complex architecture, which consists of regionally distributed and aligned collagen fibers, glycosaminoglycans (GAGs), and a high-water content. GAGs represent the aqueous component of the meniscus and are primarily responsible for its shock-absorbing capacity. Their high swelling ability and fixed negative charges enable them to absorb water during osmotic imbalance, acting as a cushion under mechanical deformation1.
Traditional tissue engineering strategies have often relied on highly crosslinked hydrogels to mimic the hydrated portion of the meniscus2. However, these hydrogels tend to be brittle and restrict polymer chain flexibility, in contrast to the semi-flexible nature of GAGs.
In this study, we introduce a self-healing hydrogel system designed to better replicate the dynamic and hydrated environment provided by GAGs in native meniscus tissue. Self-healing gels form dynamic, reversible bonds that enable rapid structural reorganization (within 10 minutes), leading to a two-fold reduction in loss factor compared to conventional hydrogels. This dynamic behavior enhances mechanical resilience and reduces the risk of long-term deformation (creep). Additionally, the self-healing gels are non-cytotoxic (cell viability >80%) and promote cell migration and spreading. The resulting bioink demonstrates improved mechanical integrity and a closer functional resemblance to the GAG-rich phase of native meniscus tissue.
Figure1. Alginate-Borax based gel stability and self-healing after 1 hour in 37°C (left), frequency sweep of the gel with relaxation spectrum (middle), cell viability in gel after one week (right)
References
1. Kiani, C.; Chen, L.; Wu, Y. J.; Yee, A. J.; Yang, B. B., Structure and Function of Aggrecan. Cell Res. 2002, 12 (1), 19-32.
2. Barceló, X.; Scheurer, S.; Lakshmanan, R.; Moran, C. J.; Freeman, F.; Kelly, D. J., 3d Bioprinting for Meniscus Tissue Engineering: A Review of Key Components, Recent Developments and Future Opportunities. Journal of 3D Printing in Medicine 2021, 5 (4), 213-233.
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