Interaction of porcine gastric mucin with various polycations and its influence on the boundary lubrication properties

摘要: Abstract The interaction of porcine gastric mucin (PGM) with polycations possessing amine functional groups, including polyallylamine hydrochloride (PAH), poly- l -lysine (PLL) and polyethylenimine (PEI), was examined from a tribological standpoint at self-mated polydimethylsiloxane (PDMS) interface. In all cases, PGM interacted the cationic polymers, leading to smaller size aggregates compared PGM, surface charge compensation, distortion protein conformation. But, synergistic lubrication effect clearly observed only 1/1 (w/w) mixture branched PEI (B-PEI) where friction coefficient reduced by two orders magnitude neat or B-PEI in speed range 0.25–100 mm/s. This attributed smallest hydrodynamic “sphere-like” conformation due high degree branching, which favors tenacious complexation fast adsorption, continuous reformation lubricating layer under cyclic tribostress pin-on-disc tribometry.