Gradzielski, M. | Search bioRxiv

bioRxiv2024

A comprehensive characterization of the viscoelastic properties of Bovine Submaxillary Mucin (BSM) and the effect of additives

This study presents a comprehensive characterization of the viscoelastic and structural properties of Bovine Submaxillary Mucin (BSM), which is widely used as a commercial source to conduct mucus-related research. We conducted concentration studies of BSM and examined the effects of various additives - NaCl, CaCl2, lysozyme, and DNA - on its rheological behavior. A notable connection between BSM concentration and viscoelastic properties was observed, particularly under varying ionic conditions. The rheological spectra could be well-described by a fractional Kelvin-Voigt Model with a minimum of model parameters. A detailed proteomics analysis provided insight into the molecular interactions within BSM, showing MUC19 as main component. Cryo-scanning electron microscopy allowed to visualize the network structure in relation to the rheological data. By elucidating the complex interplay between mucin concentration, environmental conditions, and viscoelastic properties, this research significantly contributes to the field of mucus research and lays an important basis for its further advancement.

biophysics↗

bioRxiv2024

Ileal mucus viscoelastic properties differ in Crohns disease

Crohns disease (CD) is an inflammatory bowel disease (IBD) that can affect any part of the gastrointestinal tract, frequently involving the terminal ileum. While colonic mucus alterations in CD patients have been described, terminal ileal mucus and its mechanobiological properties have been neglected. Our study is the first of its kind to decipher the viscoelastic and network properties of ileal mucus. With that aim, oscillatory rheological shear measurements based on an airway mucus protocol that was thoroughly validated for ileal mucus were performed. Our pilot study analyzed terminal ileum mucus from controls (n=11) and CD patients (n=11). Mucus network structure was visualized by scanning electron microscopy (SEM). Interestingly, a statistically significant increase in viscoelasticity as well as a decrease in mesh size was observed in ileal mucus from CD patients compared to controls. Furthermore, rheological data were analyzed in relation to study participants clinical characteristics, such as inflammatory status, revealing noteworthy trends. In conclusion, this study provides the first data on the viscoelastic properties and structure of human ileal mucus in the healthy state and in CD, demonstrating significant alterations between groups and highlighting the need for further research on mucus and its effect on the underlying epithelial barrier.

biophysics↗