Effects of hyaluronan on engineered articular cartilage extracellular matrix gene expression in 3-dimensional collagen scaffolds

摘要

Hyaluronan (HA) is a component of cartilage matrix with known effects on chondrocytes. We tested the effects of adding HA to 3-dimensional (3-D) collagen sponges on chondrocyte function in nitro. Bovine articular chondrocytes isolated by collagenase digestion were injected into either collagen or HA/collagen scaffolds comprising different amounts of HA (2, 5, 10, and 14 percent w/w). Expression of aggrecan and type II collagen genes was measured by gene-specific quantitative competitive reverse transcrip-tase-polymerase chain reactions, and the extracellular matrix was estimated by histomorphometrical analyses. After 7-day culture, the chondrocytes in 2 percent (w/w) HA sponges expressed fourfold more mRNA transcripts for type II collagen (p=0.002) and twofold more mRNA transcripts for aggrecan (p=0.022) than in control collagen sponges. Furthermore, there was 45 percent more extracellular matrix in 2 percent (w/w) HA sponges and 43 percent less matrix in the 10 percent (w/w) HA sponges compared with plain collagen sponges (p > 0.05). In sum, a small amount of HA in 3-D collagen scaffolds enhanced chondrogenesis, but a greater amount was inhibitory. This 3-D system represents a novel tool to identify mechanisms by which extracellular matrix molecules influence chondrocyte function. Further, these results show the potential for modifying scaffolds to improve production of engineered cartilage for in vivo applications.