Bioinspired artificial synovial fluid for in vitro frictional behavior of bovine articular cartilage and auxiliary biomaterials

Abstract

Synovial fluid is a non-Newtonian substance that lubricates the space between the diarthrodial joints produced by the synovial membrane. The properties pertaining to the rheology of the synovial fluid play a significant role in mimicking the frictional and wear behavior of articular cartilage as similar to native tissue. Most of the researchers used the bovine serum for conducting tribological studies. However, the bovine serum obtained from the different laboratories does not execute properties similar to the native synovial fluid. Hence, it is essential to develop synthetic synovial fluid. The researchers used immunoglobulins G (IgG) derived from human or animal serum to prepare synovial fluid. The average cost of IgG is approximately $10/mg. The current research proposed the bovine colostrum-derived IgG and glycerol to develop the artificial synovial fluid (ASF). Bovine colostrum comprises 42 to 90 mg/ml of IgG, which is inexpensive and easy availability. The foremost supplements for preparing ASF include sodium hyaluronate, bovine serum albumin, lecithin, and ringer solution. The composition of each element is adjusted to obtain the requisite rheological properties and compared the same with human synovial fluid from the literature. Rheological, wettability and tribological characterization were carried out to evaluate the performance of developed ASF. All the ASF samples exhibited good rheological properties with excellent hydrophilic behavior. The lower coefficient of friction (0.03 to 0.085) was observed for the cartilage-cartilage and meniscus-cartilage pair. The developed fluid exhibited admirable lubrication properties and was comparatively economical. Hence, the proposed ASF was a promising fluid for conducting in vitro tribological studies on articular cartilage and auxiliary biomaterials.