Controlling Enzymatic Degradation of Carboxyl-Modified Chitosan and Hyaluronic Acid Biopolymers Using Dynamic Covalent Cross-Linking

The enzymatic degradation of hyaluronic acid (HA) and carboxyl-modified chitosan (CC) polymers in aqueous dispersions can be controlled by dynamic covalent cross-linking. Unlike un-cross-linked HA, dynamic covalent cross-linking preserves the viscoelastic behavior of HA dispersions when exposed to hyaluronidase enzyme. Among the dynamic covalent cross-linked CC dispersions, only dispersions with degrees of deacetylation of 98% (CC98) partially upheld the viscoelastic behavior under lysozyme-mediated degradation. Overall, our results suggest that dynamic covalent cross-linking can produce injectable HA and CC dispersions with partial enzymatic degradation resistance.