Effect of Triamcinolone Treatment on the Mechanical Properties of Cartilage

• Cameron Baines, Mechanical Engineering, University of Delaware

• X. Lucas Lu, Mechanical Engineering, University of Delaware

Triamcinolone Acetonide (TA) is a corticosteroid commonly used to reduce synovial inflammation following traumatic joint injury. Untreated inflammation can lead to osteoarthritis, which is the breakdown of cartilage within a joint causing swelling, pain, and mobility restrictions. Cartilage breakdown can be indicated experimentally by evaluating the cartilage mechanical properties. To simulate the inflammatory response after an injury, cartilage samples were treated with  the pro-inflammatory cytokine interleukin 1-β. Samples were then also treated with TA, to see if the addition of the steroid affected the mechanical properties of the inflamed cartilage. Cartilage mechanical properties  were determined using micro-indentation. An indenter tip of diameter 300 µm was used on cartilage samples of cartilage three mm in diameter. A tare load of 0.2g was applied to let the cartilage adjust to the force, followed by a 2g creep load. The resulting  total force is 2.2 g,  applied for a total of 10 minutes. Raw data is collected and then run through a Matlab code to produce a curve fit that smooths the data and can be further analyzed to determine the mechanical properties of the sample. We have focused on running indentation tests and streamlining the process with small adjustments such as changing the speed at which the indenter moves. We ran into problems with samples being difficult to get glued down to the testing device so the process had to be sped up to minimize the time that the cartilage had to dry out. Tests will continue to be carried out on treated samples so that the results can be compared to the control to look for any benefits that the drugs may offer.