The experimental study of intra-articular carboxymethylated chitosan injection for the prevention of cartilage degeneration of osteoarthritis in knees

Objective To observe the influence of intra-articular injection of carboxymethylated chitosan(CMCTS) on cartilage degeneration and mRNA expression of matrix metalloproteinase-1,-3(MMP-1,-3) and tissue inhibitor of metalloproteinase-1(TIMP-1) in cartilage of osteoarthritis(OA) model.Methods Thirty-two white rabbits underwent unilateral anterior cruciate ligament transection(ACLT) and divided into A-D groups.The rabbits in group A received 0.3 ml of intra-articular 2% high molecular weight(MW) CMCTS injection immediately after surgery,once two weeks,those in group B were treated under the same conditions using low MW CTCTS and those in group C received(0.3) ml of intra-articular 1% sodium hyaluronate(SH) injection immediately after surgery,once a week.Animals in group D were not injected after ACLT.At 6th week after surgery,the rabbits were sacrificed.The cartilage changes on the medial femoral condyles were graded separately.Gene expression of MMP-1,-3 and TIMP-1 was detected by using reverse transcription-polymerase chain reaction(RT-PCR).Results Cartilage degeneration in untreated group was significantly more severe than that in CMCTS and SH injection groups.In cartilage,the expression of MMP-1 and MMP-3 mRNA was suppressed in the CMCTS injection groups and there was no significant difference between high and low MW CMCTS injection groups.No difference in MMP-1 and MMP-3 expression was found between SH injection group and untreated group.No difference in TIMP-1 expression was observed in cartilage among the groups.Conclusion CMCTS could significantly downregulate the mRNA expression of MMP1,-3 and reduce severity of cartilage degradation.CMCTS may have a protective effect on articular cartilage.