An organ culture model for assaying wound repair of the fibrocartilaginous knee joint meniscus

Abstract

We describe an in vitro organ culture system that can be used to test the effect of various substances and compounds on the wound healing process in the fibrocartilaginous substance of the knee joint meniscus. Using culture medium containing either 10% fetal bovine serum (FBS) or our recently developed serum-free, defined culture medium (DM), we have demonstrated the ability of meniscal fibrochondrocytes from intact rabbit menisci to extricate themselves from their surrounding matrix and migrate into an exogenous, purified fibrin clot in vitro. After 4 weeks of culture in FBS-containing medium, the cells which had invaded the clot had initiated the early aspects of a typical reparative response; the same response did not occur in DM alone. Morphologically, the cells on the surface of the clot resembled the original superficial fibrochondrocytes, whereas those cells within the substance of the clot more closely resembled the original deep fibrochondrocytes. After 10 weeks, the reparative response had progressed only to a certain point and then failed to progress further under these culture conditions. However, use of this culture system should now make it possible to rapidly identify and quantitate those factors which would most likely be useful in continuing the reparative response and in affecting meniscal wound repair. Elucidation of the mechanisms and requirements for meniscal healing will eventually allow the practicing orthopaedic surgeon to effect in situ meniscal repair and obviate the need for meniscectomy and its morbid sequelae.

Porosity and Cell Preseeding Influence Electrospun Scaffold Maturation and Meniscus IntegrationIn Vitro

“…While the results described above demonstrate the promise of a cellularized, highly porous, aligned nanofibrous scaffold for meniscus repair, there remain additional considerations that should be addressed as this technology moves toward in vivo, clinical translation. For example, while the concentric explant model has been used extensively to assess integration, 20,36,37 it does not test the most physiologically relevant forces experienced by the meniscus or the clinical scenario of replacement. Implanted engineered meniscus scaffolds will be exposed to simultaneous compressive forces and tensile forces, rather than the shear forces that arise in the push-out testing modality.…”

Meniscus Reconstruction Through Coculturing Meniscus Cells with Synovium-Derived Stem Cells on Small Intestine Submucosa—A Pilot Study to Engineer Meniscus Tissue Constructs

“…In an in vitro culture system, meniscus fibrochondrocytes have been shown to be capable of extricating themselves from their surrounding matrix and migrating into a purified fibrin clot. 42 In vivo studies have also shown the efficacy of an exogenous fibrin clot to support a repair response in the avascular portion of the meniscus. 14,22 Therefore, fibrin can be considered a quintessential model for the matrices on which tissue-engineered menisci are created; it provides a deformable scaffold for even cell distribution, migration, and orientation, and the ability to degrade over time.…”

Primary culture of microvascular endothelial cells from canine meniscus

“…In an effort to promote healing in the avascular region of the meniscus, Arnoczky et al (4) demonstrated in vivo that, when meniscal defects in this region are filled with a fibrin clot, a fibrocartilage repair tissue is generated. With an in vitro model, Webber et al (16) demonstrated that a fibrin clot filled defect would heal only partially; this suggested that factors other than the fibrin clot itself are required for effective healing.…”