Abstract
Repair or regeneration of hyaline cartilage in knees, shoulders, intervertebral discs, and other assorted joints is a major therapeutic target. To date, therapeutic strategies utilizing chondrocytes or mesenchymal stem cells are limited by expandability or the generation of mechanically inferior cartilage. Our objective is to generate robust cartilage-specific matrix from human mesenchymal stem cells suitable for further therapeutic development. Human mesenchymal stem cells, in an alginate 3D format, were supplied with individual sugars and chains which comprise the glycan component of proteoglycans in articular cartilage (galactose, hyaluronic acid, glucuronic acid, and xylose) during chondrogenesis. After an initial evaluation for proteoglycan deposition utilizing Alcian blue, the tissue was further evaluated for viability, structural elements, and hypertrophic status. With the further addition of serum, a substantial increase was observed in viability, the amount of proteoglycan deposition, glycosaminoglycan production, and an enhancement of Hyaluronic Acid, Collagen II and Aggrecan deposition. Suppression of hypertrophic markers (COL1A1, COL10A1, MMP13, and RUNX2) was also observed. When mesenchymal stem cells were supplied with the raw building materials of proteoglycans and a limited amount of serum during chondrogenesis, it resulted in the generation of viable hyaline-like cartilage with deposition of structural components which exceeded previously reported in vitro-based cartilage.