Understanding the surface interactions in biological systems is very important but difficult due to its complexity from various molecules with different properties. Moreover, there are not many researchers studying biological systems at the molecular scale with a chemical engineering perspective. Contributing to the knowledge of biological systems from new perspectives can not only give a better understanding of the biological systems themselves but also possibly help to find different and innovative ways to prevent and treat diseases that are associated with the biological systems. The objectives of this research were to investigate the molecular mechanisms of (i) myelin adhesion, and (ii) articular cartilage lubrication.

Myelin, which is a multi-lamellar structure of asymmetric lipid bilayers, requires a sufficient inter-membrane adhesion for stability of the tissue structure. When the structure is disrupted, myelin eventually deteriorates, leading to demyelinating diseases such as multiple sclerosis. The lipid composition was found to be a critical factor; even a slight change in lipid composition alters the lipid domain distribution and membrane fluidity, which changes the myelin basic protein (MBP) adsorption mechanism. Abnormal adsorption of MBP can lead to a decrease in inter-membrane adhesion, which could be one of the main molecular reasons for demyelination of myelin tissue.

Articular cartilage, mainly responsible for smooth, well-lubricated, and painless motion of joints, is a very robust tissue that can bear load and friction throughout a human's life. Osteoarthritis is a disease where the cartilage malfunctions due to damage (caused by many situations e.g., injury, obesity, and infection), which is characterized by excessive pain. In this study, the hyaluronic acid (HA) trapping mechanism has been proposed which is an effective way for HA to act as a boundary lubricant at a sufficiently high load and shear rate. Also, the importance of HA grafting and grafted HA molecular weight on wear protection and synergistic properties have been investigated. Finally, stick-slip friction has been proposed as a possible cartilage wear mechanism.