The excessive production of thick, viscous mucus in severe respiratory diseases leads to obstruction of the airways and provides a suitable environment for the colonization of pathogenic bacteria.
Mona Ahonen, a fourth-year graduate student in Professor Mark Schoenfisch's research group, published in ACS Biomaterials Science & Engineering, evaluates the effect of nitric oxide, NO, releasing alginates with varying NO release kinetics on the viscoelastic properties of human bronchial epithelial, HBE, mucus, as a function of the NO-release kinetics using parallel plate rheology.
Low-molecular-weight, ∼5 kDa, alginates with high NO flux, ∼4000 ppb/mg, and sustained release, half-life ∼0.3 h, proved to be most effective in reducing both mucus elasticity and viscosity, ≥60% reduction for both.
The efficacy of the NO-releasing alginates was shown to be dose-dependent, with high concentrations of NO-releasing alginates, ∼80 mg·mL–1, resulting in greater reduction of the viscosity and elasticity of the mucus samples. Greater reduction in mucus rheology was also achieved with NO-releasing alginates at lower concentrations when compared with both NO-releasing chitosan, a similarly biocompatible cationic polymer, and N-acetyl cysteine, NAC, a conventional mucolytic agent.
While the exact mechanism by which NO alters the rheological properties is yet to be fully elucidated, the results presented in this work suggest that the addition of NO dramatically increases the mucolytic potency of the alginate biopolymers.