The lubricity of mucin solutions is robust toward changes in physiological conditions

TL;DR

This study systematically examines how physiological variations affect the lubricating properties of mucin solutions, demonstrating their robustness and potential for biomedical applications across diverse conditions.

Contribution

It provides the first comprehensive analysis of mucin solution lubricity under various physiological conditions, revealing their robustness and mechanistic insights.

Findings

Mucin solutions maintain excellent lubricity at low concentrations.

Lubricity is preserved across a wide pH range and high ionic strength.

Variations in composition can limit mucin lubricating potential.

Abstract

Solutions of manually purified gastric mucins have been shown to be promising lubricants for biomedical purposes, where they can efficiently reduce friction and wear. However, so far, such mucin solutions have been mostly tested in specific settings, and variations in the composition of the lubricating fluid have not been systematically explored. We here fill this gap and determine the viscosity, adsorption behavior, and lubricity of porcine gastric mucin solutions on hydrophobic surfaces at different pH levels, mucin and salt concentrations and in the presence of other proteins. We demonstrate that mucin solutions provide excellent lubricity even at very low concentrations of 0.01 % (w/v), over a broad range of pH levels and even at elevated ionic strength. Furthermore, we provide mechanistic insights into mucin lubricity, which help explain how certain variations in physiologically relevant parameters can limit the lubricating potential of mucin solutions. Our results motivate that solutions of manually purified mucin solutions can be powerful biomedical lubricants, e.g. serving as eye drops, mouth sprays or as a personal lubricant for intercourse.