Chondrocyte aggregation and reorganization into three-dimensional scaffolds

Articular cartilage has a very limited self-repairing capacity; thus, chond ral lesions normally result in chronic degeneration and, eventually, osteoa rthritis development. Currently, tissue engineering offers a new tool for t he clinical treatment of osteochondral defects. The present investigation a imed to develop an in vitro engineered cartilage using a new class of semis ynthetic scaffolds. Two nonwoven meshes of hyaluronan esters (Hyaff(R) deri vatives) were seeded with sternal chick embryo chondrocytes cultured for up to 21 days, after which time they were assessed for both the cellular grow th profile and histological features. Avian chondrocytes easily adhered and proliferated onto hyaluronan-based scaffolds, demonstrating a significant preference for the fully esterified benzylic form. Histochemical staining r evealed the presence of a neosynthesized glycosaminoglycan-rich extracellul ar matrix, and immunohistochemistry confirmed the deposition of collagen ty pe II. Moreover, ultrastructural observations supported evidence that chond rocytes grown onto a hyaluronan-derived three-dimensional scaffold maintain ed their unique phenotype and organization in a cartilage-like extracellula r matrix. These findings support the further pursuit of a transplantable en gineered cartilage using human chondrocytes for the regeneration of chondra l lesions. (C) 1999 John Wiley & Sons, Inc. J Biomed Mater Res, 46, 337-346 , 1999.