Transplantation of Chemically Processed Decellularized Meniscal Allografts

Abstract

Objective. The aim of this study was to evaluate the chondroprotective effect of chemically decellularized meniscal allografts transplanted into the knee joints of adult merino sheep. Methods. Lateral sheep meniscal allografts were chemically processed by a multistep method to yield acellular, sterile grafts. The grafts were transplanted into the knee joints of sheep that were treated by lateral meniscectomy. Joints treated by meniscectomy only and untreated joints served as controls. The joints were analyzed morphologically 6 and 26 weeks after surgery by the macroscopical and histological OARSI (Osteoarthritis Research Society International) score. Additionally, the meniscal grafts were biomechanically tested by cyclic indentation. Results. Lateral meniscectomy was associated with significant degenerative changes of the articular cartilage of the lateral joint compartment. Transplanted lateral meniscal allografts retained their integrity during the observation period without inducing significant synovitis or foreign body reactions. Cellular repopulation of the grafts was only present on the surface and the periphery of the lateral meniscus, but was still completely lacking in the center of the grafts at week 26. Transplantation of processed meniscal allografts could not prevent degenerative changes of the articular cartilage in the lateral joint compartment. Compared with healthy menisci, the processed grafts were characterized by a significantly reduced dynamic modulus, which did not improve during the observation period of 26 weeks in vivo. Conclusion. Chemically decellularized meniscal allografts proved their biocompatibility and durability without inducing immunogenic reactions. However, insufficient recellularization and inferior stiffness of the grafts hampered chondroprotective effects on the articular cartilage.

Comparison of High‐Hydrostatic‐Pressure Decellularized Versus Freeze‐Thawed Porcine Menisci

“…44 Only a few reports have shown recellularization of menisci. 45 For example, Gelse et al 46 transplanted chemically processed decellularized meniscus into merino sheep. They evaluated the cell infiltration into transplanted menisci, but the recellularization was insufficient.…”

Age‐related morphometric changes of the tidemark in the ovine stifle

“…The use of the sheep as an animal model for osteoarthritis requires the surgical induction of the disease to ensure the development of moderate to severe cartilage damages (Little et al, ). For example, in a lateral meniscectomy model, average OARSI scores can reach up to 16 ± 3 for cartilage (with erosion of cartilage and loss of proteoglycans to the mid/deep zone), associated with moderate synovitis and osteophytes in the lateral femoral and tibial condyles (Gelse et al, ). Obviously, such cases were not identified in the current population.…”

Development of A Decellularized Meniscus Matrix-Based Nanofibrous Scaffold for Meniscus Tissue Engineering

“…In addition, laboratory-based studies have developed regenerative scaffolds that utilize decellularized meniscus ECM. Examples include using the whole piece of lyophilized tissue directly as a graft [15][16][17], reconstituting pulverized tissue into porous or hydrogel constructs [18][19][20], 3D printing with ECM-based bioinks [21][22][23][24][25], electrospinning from solutions containing natural structural proteins similar to those present in the meniscus ECM [26][27][28], or a combination of the above strategies [29,30]. Many of the studies have demonstrated improved meniscus cell or stem cell viability, infiltration, and neo-matrix deposition over time.…”

“…However, there are limitations associated with each of the above approaches. In the cases of decellularized whole meniscus transplantation, inadequate mechanical strength could lead to construct ruptures and joint deterioration, and insufficient recellularization could hamper chrondroprotective effects [15, 17]. While building bioactive scaffolds reconstituted from ECM components on hydrogel extrusion or casting platforms could provide more flexibility in terms of matching the gaps in various meniscus tears, the substrate stiffness and porosity need to be meticulously tuned to encourage cell spreading and migration [18, 20].…”