Hyaluronic acid alkyl derivative: A novel inhibitor of metalloproteases and hyaluronidases

• A bioactive alkyl derivative of HA was selected among other GAG derivative.
• HA hexadecyl derivative showed higher inhibition potency against MMP13 and MMP8.
• Human MMP13 and Hyal-2 inhibition were demonstrated in synovial fluid.
• HA derivatization gave biological activity in addition to mechanical properties.

Extracellular matrix (ECM) degradation, one of the main features of osteoarthritis, is driven by at least two major classes of enzymes: matrix metalloproteases (MMPs) and hyaluronidases. Among certain glycosaminoglycans, including natural and chemically cross-linked HAs, which are currently used as viscosupplements, the hyaluronic acid (HA) alkyl-amides (Hyadd) were here selected as the strongest MMP and hyaluronidase inhibitors. We used C. histolyticum collagenase (ChC) and bovine testicular hyaluronidase (BTH) as representative models of human MMPs and hyaluronidases, respectively. The role of the alkyl moiety was investigated using HA derivatives with varying alkyl lengths and degrees of derivatization. The selected compound was then screened against 10 different human MMPs in vitro, and the results were validated ex vivo in human synovial fluid. Hyadd-C16, identified as a lead compound, showed the highest inhibition potency against MMP13 and MMP8. The in vitro results were confirmed by the inhibition of human MMP13 (Ki = 106.1 μM) and hyaluronidase-2 in the synovial fluid of patients with osteoarthritis. This study demonstrates the unique properties of Hyadd-C16, including its remarkable enzymatic inhibitory activity, which is conferred by the hydrophobic chain, and its high biocompatibility and water solubility of the HA backbone.