2017 Mucin-Inspired Lubrication on Hydrophobic Surfaces

Authors: Benjamin T. Käsdorf^a, Florian Weber^a, Georgia Petrou^b, Vaibhav Srivastava^b, Thomas Crouzier^b, Oliver Lieleg^a

Journal: Biomacromolecules 2017, 18, 8, 2454-2462, https://doi.org/10.1021/acs.biomac.7b00605

Institutes:

^aDepartment of Mechanical Engineering and Munich School of Bioengineering, Technical University of Munich, Boltzmannstrasse 11, 85748, Garching, Germany

^bDivision of Glycoscience, School of Biotechnology, Royal Institute of Technology, Albanova University Center, 10691 Stockholm, Sweden

Abstract:

In the human body, high-molecular-weight glycoproteins called mucins play a key role in protecting epithelial surfaces against pathogenic attack, controlling the passage of molecules toward the tissue and enabling boundary lubrication with very low friction coefficients. However, neither the molecular mechanisms nor the chemical motifs of those biomacromolecules involved in these fundamental processes are fully understood. Thus, identifying the key features that render biomacromolecules such as mucins outstanding boundary lubricants could set the stage for creating versatile artificial superlubricants. We here demonstrate the importance of the hydrophobic terminal peptide domains of porcine gastric mucin (MUC5AC) and human salivary mucin (MUC5B) in the processes of adsorbing to and lubricating a hydrophobic PDMS surface. Tryptic digestion of those mucins results in removal of those terminal domains, which is accompanied by a loss of lubricity as well as surface adsorption. We show that this loss can in part be compensated by attaching hydrophobic phenyl groups to the glycosylated central part of the mucin macromolecule. Furthermore, we demonstrate that the simple biopolysaccharide dextran can be functionalized with hydrophobic groups  which confers  efficient surface adsorption and good lubricity on PDMS to the polysaccharide.