The effects of carboxymethylated chitosan on metalloproteinase-1, -3 and tissue inhibitor of metalloproteinase-1 gene expression in cartilage of experimental osteoarthritis.

The aim of this study was to evaluate the effects of intra-articular injection of carboxymethylated chitosan (CMCTS) on mRNA expression of matrix metalloproteinase-1, -3 (MMP-1, -3) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in cartilage of osteoarthritis (OA). 32 white rabbits underwent unilateral anterior cruciate ligament transection (ACLT) and were randomly divided into four groups 5 weeks after transection. Rabbits of group A received 0.3 ml intra-articular injection of 2% high molecular weight CMCTS, once 2 weeks. Rabbits in group B were treated under the same condition using 2% CMCTS with low molecular weight. Group C rabbits received 0.3 ml of intra-articular 1% sodium hyaluronate (HA) injection, once a week. Animals of group D were not injected as controls after ACLT. At death, 11 weeks following surgery, the mRNA expressions of MMP-1, MMP-3 and TIMP-1 of degenerative cartilage were analyzed using reverse transcription-polymerase chain reaction. The mRNA levels of MMP-1 and MMP-3 in cartilage of CMCTS injection groups were significantly lower than those of HA-treated group and untreated group. There was no significant difference in MMP-1 and MMP-3 expression between the different molecular weight CMCTS injection groups. No significant difference in MMP-1 and MMP-3 expression in cartilage was found between HA injection group and control group. No significant difference in TIMP-1 expression was observed in cartilages of any group. CMCTS may significantly suppress the mRNA expression of MMP-1 and MMP-3 in cartilage during the early stages of OA. CMCTS may have a protective effect on articular cartilage of OA.