Synoviocyte neotissues towards in vitro meniscal tissue engineering

Meniscal injuries are a common cause of pain and osteoarthritis in dogs. We describe here the production of synoviocyte-derived autologous neotissues for potential application in meniscal tissue engineering, via two different culture techniques: contracted or tensioned synthesis of synoviocyte neotissues. Synoviocytes were obtained during routine stifle arthroscopy and cultured from 14 dogs with naturally occurring osteoarthritis of the stifle. Neotissues were analyzed for meniscal-like matrix components and their gene expression, inflammatory gene expression, and cell viability. Tension improved cell viability, and, independent of cell viability, fibrochondrogenic activity by promoting expression of collagen type 1 and aggrecan genes and attenuating gene expression of IL-6. Through this mechanism tension increased collagen protein content and chondrogenic index of neotissues. Alpha smooth muscle actin was present in all neotissues and was responsible for grossly visible contractile behavior. Application of tension to synoviocytes may be a viable culture method towards in vitro meniscal tissue engineering.