N. Fackler (Washington, US)
UC Irvine Biomedical EngineeringPresenter Of 1 Presentation
24.3.5 - In Vitro Effects of Methylprednisolone and Triamcinolone on the Viability and Mechanics of Native and Engineered Cartilage Grafts
Abstract
Purpose
To investigate the in vitro effects of a single Methylprednisolone (MP) or Triamcinolone (TA) exposure on the viability, mechanics, and biochemical content of native articular cartilage explants and engineered neocartilage.
Methods and Materials
Articular cartilage explants were harvested from the femoral condyle of the bovine stifle, and neocartilage constructs were engineered from bovine stifle chondrocytes using the scaffold-free, self-assembling process. Both explants and neocartilage were exposed to chondrogenic medium containing a clinical dose of MP or TA for one hour, followed by fresh medium wash and exchange. At t=24 hours post-treatment, samples were assessed for viability (live/dead), mechanical properties (creep indentation and Instron tensile testing), and biochemical (collagen and glycosaminoglycan) content.
Results
Single steroid exposure was chondrotoxic in both explants and neocartilage constructs (Figure 1). Mean cell viability was significantly decreased in native explants and neocartilage constructs exposed to MP (35.5% and 30.2%, respectively) compared to control (49.8%, p < 0.001 and 36.8%, p = 0.062, respectively) and TA (45.7%, p = 0.003 and 37.3%, p = 0.04, respectively). No significant differences in collagen and glycosaminoglycan content were found within steroid treatment groups. There was significant weakening of mechanical properties of steroid-treated native explants when compared to control, with decreases in aggregate modulus (646.3 kPa vs 312.8 kPa (MP) and 257.0 kPa (TA), p < 0.001), shear modulus (370.1 kPa vs 191.2 kPa (MP) and 157.4 kPa (TA), p < 0.001), and ultimate tensile strength (UTS) (9.650 MPa vs 5.648 MPa (MP, p = 0.021) and 6.065 MPa (TA), p = 0.0403) (Figure 2). No significant differences in mechanical properties of engineered neocartilage were found among groups.
Conclusion
Single exposure of MP or TA resulted in chondrotoxicity and weakening of mechanical properties of native cartilage explants compared to control. Clinicians should be judicious regarding use of intra-articular steroids in the setting of cartilage repair.