Low-intensity ultrasound alleviate pathogenesis of experimental arthritis in rabbit

초록

We have previously established that low intensity ultra sound (LIUS) enhanced differentiation of cultured chondrocytes in vitro. The objective of this study was to examine possible effects of LIUS in preventing pathogenesis of OA following administration of Hyaluronan (HA) in ACLT model in Rabbit. Labeled HA was injected into the joint cavity of adult New Zealand white rabbits through the patellar tendon with a needle point placed at patellofemoral joint to avoid damage to the synovial membrane. The joint of right knee was stimulated for 10 min every day using continuous wave at the frequency 0.8MHz signals with intensity of 400 mW/cm2 for 13day. The left knee joint was exposed to sham ultrasound as a control. 0.1 ml synovial fluids were collected on the 1st day, 4th, 7th, 10th day after injection of HA for analysis. Synovia were removed from certain portions of the medial parapatella synovium in the knee joints at thirteen days after the last LIUS stimulation. Histological analysis showed that LIUS treatment prevented cartilage and synovia deterioration to some measurable degree. In those ACLT animals treated with HA, the proteoglycan and type II collagen distribution in articular cartilage was far better than OA control but additional treatment with LIUS resulted in a cartilage closely resemble those of the normal. Analysis of synovium from ACLT animals showed enhanced inflammatory factors, prostaglandin E2, and MMP-3 levels. HA treatment induced decreased expression levels of PG E2 and MMP-3. LIUS treatment caused further lowering of these inflammatory factors. LIUS also induced significant absorption of High molecular weight HA into synovia. These results indicated that LUIS alleviated the pathogenesis of OA model in cartilage deterioration and enhanced delivery of high molecular weight biologic therapeutics in synovia.