2025 Improving the lubricity of commercial mucins via conjugation with catechol-like molecules

Authors:
Bernardo Miller Naranjo, Chiara Gunnella, Helena Wagner and Oliver Lieleg

Journal:
RSC Appl.Polym. DOI: 10.1039/d5lp00115c

Institute:

TUM School of Engineering and Design, Department of Materials Engineering, Technical University of Munich, Boltzmannstraße 15, 85748 Garching, Germany

Center for Protein Assemblies (CPA) and Munich Institute of Biomedical Engineering (MIBE), Technical University of Munich, Ernst-Otto-Fischer Straße 8, Garching, Germany

Abstract:

There is a range of diseases related to the insufficient lubrication of tissue surfaces. Typically, this occursas a consequence of the reduced or incomplete production of the macromolecular key components ofthe respective biolubricant. Thus, developing substitute macromolecules to mitigate friction (and painresulting thereof) in poorly lubricated joints, on the eyes, or in the oral cavity is an important task in thefield of biomaterials science. To date, commercially available biomacromolecules such as hyaluronic acid(HA) and porcine gastric mucin (PGM) have mostly been in the focus of biolubrication research. However,their ability to reduce friction and surface damage generation is limited, which calls for novel approaches.Here, we create chemical modifications of commercial PGM by conjugating different catechol-like mole-cules (Levodopa (L-Dopa), 3,4,5-trihydroxybenzamide (THBA), or tannic acid (TA)) to the glycoprotein.Whereas solutions comprising unmodified PGMs exhibit poor lubricity, the conjugates show significantlyimproved surface adhesion and lubrication properties, with the TA–PGM conjugate performing the best.This particular conjugate also mitigates wear formation on PDMS and articular cartilage surfaces equallywell as lab-purified porcine gastric mucin and, on hydrophilic surfaces, provides lubricity that even out-performs that of solutions comprising chemically intact, in-lab purified mucins. Ourfindings pave the waytowards the production of a highly versatile biolubricant that can have a broad range of biomedical appli-cations: as a biocompatible viscosupplement in osteoarthritic joints, as a lubricant additive after knee orhip implant surgery, as a component for artificial tearfluids, or for the treatment of xerostomia.