Objective: The present study was conducted to compare the neocartilages generated in scaffolds and scaffold-free, agarose gel-supported primary chondrocyte cultures.
Design: Six million bovine primary chondrocytes were embedded in HyStem™ or HydroMatrix™ scaffolds, or scaffold-free in chondrocyte culture medium, and then loaded to agarose gel supported culture wells. Neocartilages were grown in the presence of hypertonic high glucose DMEM medium in 37 °C incubator at 20% O2 and 5% CO2 for one, three or six weeks. By the end of culture periods, the formed tissues were analyzed by histological staining for proteoglycans (PGs) and type II collagen, gene expression measurements of chondrocyte-specific genes aggrecan, Sox9 and procollagen α1(II), and procollagen α2(I) were performed using quantitative RT-PCR, and analyses of PG contents and structure were conducted by spectrophotometric and agarose gel electrophoretic methods, respectively.
Results: The neocartilage generated in scaffold-free cultures appeared slightly bigger in size than in HyStem™- or HydroMatrix™-containing scaffolds. Histology visualized that the PGs and type II collagen were abundantly present in both in scaffold-free and scaffold-containing tissues. The PG content gradually increased following the culture period. However, the mRNA expression levels of the cartilage-specific genes of aggrecan, procollagen α1(II) and Sox9 gradually decreased following culture period, while procollagen α2(I) levels increased.
Conclusions: After six weeks cultivations, the PG concentrations in neocartilage tissues manufactured with HyStem™ or HydroMatrix™ scaffolds, and in scaffold-free agarose gel-supported cell cultures, were similar to native cartilage. No obvious benefits could be seen on the extracellular matrix assembly in HyStem™ or HydroMatrix™ scaffolds cultures.
primary chondrocytes; articular cartilage; tissue engineering; neocartilage; scaffold; hyaluronan; self-assembling peptide; scaffold-free