Human knee joints move smoothly under high load conditions due to articular cartilage and synovial fluid. Much attention is paid to the role of proteoglycans. It is suggested that a part of proteoglycan forms aggregate on the cartilage surface. making a polymer brush. https://www.roneverhart.com/GLYKON-BAYONET-BEAD-BLAST-OVERLAY-STONEWASH-STANDARD-NICKEL-BORON-INTERNALS-184-10/