Collagen Type II-Chitosan Interactions as Dependent on Hydroxylation and Acetylation Inferred from Molecular Dynamics Simulations

Chitosan-collagen blends have been widely applied in tissue engineering, joints diseases treatment, and many other biomedical fields. Understanding the affinity between chitosan and collagen type II is particularly relevant in the context of mechanical properties modulation, which is closely associated with designing biomaterials suitable for cartilage and synovial fluid regeneration. However, many structural features influence chitosan's affinity for collagen. One of the most important ones is the deacetylation degree (DD) in chitosan and the hydroxylation degree (HD) of proline (PRO) moieties in collagen. In this paper, combinations of both factors were analyzed using a very efficient molecular dynamics approach. It was found that DD and HD modifications significantly affect the structural features of the complex related to considered types of interactions, namely hydrogen bonds, hydrophobic, and ionic contacts. In the case of hydrogen bonds both direct and indirect (water bridges) contacts were examined. In case of the most collagen analogues, a very good correlation between binding free energy and DD was observed.

Automated summary

Chitosan-collagen blends are commonly used in tissue engineering and biomedical fields like joints diseases treatment. Understanding the affinity between chitosan and collagen type II is crucial for designing suitable biomaterials for cartilage and synovial fluid regeneration. This study investigated the effects of deacetylation degree in chitosan and hydroxylation degree of proline moieties in collagen. The results showed that these modifications significantly influenced the structural features of the interaction between the two materials, such as hydrogen bonds, hydrophobic, and ionic contacts.