siRNAare involved in the silencing of select genes, or RNA interference (RNAi).  There are issues with delivering the siRNA to the targeted sites in vivo, and once the delivery problem is resolved, the siRNA is also problematic in that the knock-down does not always occur or the efficiency of the knock-down is not as high as needed.  TNF-α or Tumor Necrosis Factor-α is a cytokine that is involved in systemic inflammation and the degradation of cartilage.  UIC investigators have designed a cationic peptide conjugated hydrogel as a vehicle to deliver a Tumor Necrosis Factor (TNF)-α siRNA to the chondrocytes in order to combat the degenerative nature of TNF-α in cartilage.