Expanded human meniscus-derived cells in 3-D polymer–hyaluronan scaffolds for meniscus repair

Treatment options for lesions of the avascular region of the meniscus using regenerative medicine approaches based on resorbable scaffolds are rare. Recent approaches using scaffold-based techniques for tissue regeneration known from cartilage repair may be a promising treatment option for meniscal tears. The aim of the study was the investigation of meniscus matrix formation of in vitro expanded human meniscus-derived cells in a three-dimensional (3-D) bioresorbable polymer graft for meniscal repair approaches. Cultivation of the human meniscus cells was performed in a resorbable scaffold material made of polyglycolic acid (PGA) and hyaluronic acid, stabilized with fibrin glue. Cell viability and distribution of human meniscus cells in PGA–hyaluronan scaffolds were evaluated by fluorescein diacetate and propidium iodide staining. Verification of typical meniscal extracellular matrix molecules like type I and type III collagen was performed histologically, immunohistochemically and by gene expression analysis. In results, 3-D scaffold-based meniscus cultures showed high cell viability over an observational period of 21 days in PGA–hyaluronan scaffolds. On the protein level, type I collagen and proteoglycans were evident. Gene expression analysis confirmed the re-expression of meniscus-specific markers in PGA–hyaluronan scaffolds. This study demonstrated that in vitro expanded human meniscus cells allow for formation of meniscal matrix components when cultured in 3-D PGA–hyaluronan scaffolds stabilized with fibrin. These results encourage scaffold-based approaches for the treatment of meniscal lesions.