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

Abstract

AbstractThis study presents a comprehensive characterization of the viscoelastic and structural properties of Bovine Submaxillary Mucin (BSM), a good biomaterial model system for mucins and mucus in general. We conducted concentration studies of BSM and examined the effects of various additives - sodium chloride, calcium chloride, lysozyme, and DNA - on its rheological behavior. Through oscillatory and shear flow macrorheological experiments, we established a detailed correlation between the concentration of BSM and its viscoelastic properties, uncovering changes in the rheological moduli with the addition of sodium and calcium chloride, particularly at higher concentrations. This highlights the mucins responsiveness to ionic strength and composition variations. The presence of lysozyme and DNA further influenced the rheological characteristics of BSM, adding a new dimension to our understanding of mucin behavior. The rheological spectra could be well-described by a Fractional Kelvin-Voigt Model (FKVM), which allows to describe the complete behavior with a minimum of model parameters. A detailed proteomics analysis provided insight into the molecular interactions within BSM, enhancing our understanding of its structural intricacies. Complementing this, cryo-scanning electron microscopy (cryo-SEM) was employed to visualize the microstructural alterations and network properties 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 future studies and advanced applications of numerous mucin-based biomaterials.