The Friction on Cartilage Surfaces under Variable Wettability
Journal Title: Biomedical Journal of Scientific & Technical Research (BJSTR) - Year 2018, Vol 6, Issue 5
Abstract
The wettability of the articular surface of cartilage depends on the condition of its surface-active phospholipid overlay, which is structured as a multi-bilayer. We examined the characteristics of this membrane surface entity in both its normal and degenerated conditions using a combination of atomic force microscopy, contact angle measurement, and friction test. The observations have led to the conclusions that the friction coefficient is significantly dependent on the hydrophobicity (wettability) of the surface of the tissue, thereby confirming the hypothesis tested in this paper. Phospholipids are molecules present in various tissues and body fluids which are also named surfactants, substances which lower surface energy [1-3].The main phospholipid classes adsorbed onto the surface of cartilage surface-active phospholipids (SAL) were identified and quantified: phosphatidylcholine (41%), phosphatidyl ethanol amine (27%) and sphingomyelin (32%) were identified as the major components of the lipid bilayer coating a natural intact cartilage surface [4,5]. The human body naturally produces phospholipids. Phospholipids support most functions of organs, such as cardiovascular health, nerve health, liver function, digestion and, most importantly, certain phospholipids might act as boundary lubricants [1]. (Figure 1) (a) An electron microscopy image of the articular cartilage surface of a human knee demonstrating the oligo lamellar lining consisting of phospholipid bilayers [3]. The bar represents 50 nm and (b) Book cover “Articular cartilage: Lamellar-repulsive lubrication of natural joints” [1]. This smart surface characteristic creates a hydrophobic-hydrophilic balance resulting in a functional hydrophilic surface in the intact joint. One of the quantitative indicators of surface tribo chemical properties is wettability. This is measured as the contact angle between a drop of water and the reference surface, see (Figure 2a).
Authors and Affiliations
Aleksandra Mrela, Zenon Pawlak
BRONJ In A Patient with Rheumatoid Arthritis: An Unnamed Association
Bisphosphonates (BPs) are important drugs in treatment and prevention of all types of osteoporosis. BRONJ is a well known complication of BP treatment since 2002 when it was firstly described. Although most of the report...
Fast and Accurate Electrochemical Measurement of Total Antioxidant Capacity as an Alternative to Spectro photometrical Methods
Total Antioxidant Capacity or TAC is an indicator of the sample ability to scavenge free radicals despite its complex composition. It has been measured in biological fluids as an inverse biomarker of oxidative stress, wh...
Phytomedicine and Allied Compounds in Both Human and Animal Healthcare
Worldwide plants have been used for curative purposes from time immemorial. It is estimated by WHO that 80% of the population majority of this in developing countries, still rely on plant-based medicine for primary healt...
Postural Training in Age-Related Macular Degeneration Subjects: Issues and Impact
Age-related macular degeneration (AMD) is the leading cause of visual impairment and blindness after fifty years old in developed countries [1,2]. It is estimated AMD will affect 288 million of elderly in 2040 [3]. This...
Characterization of Breast Lesions Using Diffusion Kurtosis Model-Based Imaging
Objective: To investigate the characterization of breast lesions using diffusion kurtosis model-based imaging. Methods: This prospective study included 120 consecutive patients underwent preoperative DCE-MRI examinations...