Effect of Mechanical Stimulation on Histology Scores and Extracellular Matrix Content of Anatomically Sized Synoviocyte-Seeded Fibrin Hydrogels

Introduction: Meniscal tissue engineering serves as a potential alternative to current treatments for canine meniscal injury. To date, tissue-engineered meniscal implants are not available, likely due to the failure of in vitro application of optimal biomechanical stimulation appropriate for the stage of neotissue formation. The objective of this study was to observe cell-seeded hydrogels exercised in a simple knee-like bioreactor, as tested in a pilot study.

Materials and Methods: Hydrogels were formed with indentation and a stainless-steel ball was used to mimic the contact interface between the convex surface of femoral condyle. This provides static compression on the cells within the hydrogel, and was also used to generate rotatory motion when rocked with an orbital shaker. Seeded hydrogels were exercised on the shaker for either 1 or 4 hours per day, for a total of 4 weeks culture time. Hydrogels were then harvested and analyzed for histology and meniscal-like glycosaminoglycan and collagen matrix distribution and content.

Results: The glycosaminoglycan content was similar in all groups however the collagen content was higher in the control group without the artificial condyle. The superficial layer in the abaxial zone had high cell density, dense zone of collagenous neotissue, and thus higher histology score.

Discussion/Conclusion: The synoviocyte-seeded hydrogel model used in the study produced neotissue with a self-arrayed tissue transition zone. Direct static compression loading applied to the gel did not improve matrix formation over the centrifugal force from the shaker plate alone. Further study could look into groups without shaker plate culture or without static compression loadings.

Acknowledgments: The study was funded by the Oregon State University department fund.

Publication History

Article published online:
11 September 2023