Material-Mediated Degradation of the Meniscus Wound Interface Enhances Integration

Introduction Meniscus tears are one of the most common indications for arthroscopic surgery, but the limited healing of adult meniscus directs clinical practice towards resection (partial meniscectomy) rather than repair, increasing the risk for early-onset osteoarthritis. As such, methods to augment endogenous repair could promote long-term joint health after injury. Previously, we showed that the meniscus extracellular matrix (ECM) increases in density with age, and hypothesized that this constitutes a physical barrier to repair. To test this hypothesis, we treated the adult bovine meniscus wound edge with a matrixdegrading enzyme (collagenase) and showed improved cellularity and tissue integration in vitro. To localize enzymatic treatment, we developed a material-mediated delivery system in which bioactive collagenase was released from polymer nanofibers. In this study, we tested the hypothesis that these novel scaffolds would enhance cellularity and matrix formation in bovine meniscus ‘repair’ constructs in vivo (placed subcutaneously in athymic rats).