Biomechanics of lamellar-repulsive lubrication of natural joints

2^nd International Conference on Biomechanics, Bioengineering & Audiology

November 07-08, 2016 Las Vegas, USA

Zenon Pawlak

Tribochemistry Consulting, USA

Posters & Accepted Abstracts: J Bioengineer & Biomedical Sci

Abstract :

The chemical and physical nature of biological surfaces is seen in an entirely different light than that of engineering surfaces immersed in water. The lubrication mechanisms in an animal body, where the surfaces are coated with phospho-lipid (PLs) bilayers, with (PLs) lamellar phases and charged bio-macromolecules in synovial fluid, have been referred to as a â�?�?lamellar-repulsiveâ�? mechanism. Amphoteric (PLs) are the main solid-phase lubricant on the surface of an articular cartilage (AC). The lubricant is chemically attached to the surface, and is responsible for the biological lamellar-repulsive lubrication mechanism. It has been well established that the PLs bi-layers mechanism, which essentially consists of a surface amorphous layer (SAL) surrounded by a 0.155 M electrolyte synovial fluid (SF) of pH ~7.4 with high-molecular-weight charged bio-macromolecules, supports low friction. Both the friction and wettability show very similar behavior as the SAL thickness is varied. The SAL, phospholipidic lamellar phases and biomacromolecules in SF, are expected to cover cartilage surfaces and support hydrophilic lubrication. Hydration repulsion dominates the interaction between charged cartilage surfaces at nanometer separations and ultimately prevents sticking together of cartilage surfaces, even at as high pressures as 100 MPa. In this presentation, we demonstrate experimentally that the pH sensitivity of cartilage to friction provides a novel concept in joint lubrication on charged surfaces

Biography :

Email: zpawlak@xmission.com