Effect of hydrophilicity of end-grafted polymers on protein adsorption behavior: A Monte Carlo study

Monte Carlo simulation is employed to investigate protein adsorption behavior on end-grafted polymers. The effect of hydrophilicity of end-grafted polymers on protein adsorption behavior is investigated in detail. The simulation results indicate that the hydrophilicity of the end-grafted polymers can affect both the amount and speed of protein adsorption. An increase in the hydrophilicity of the end-grafted polymers can significantly decrease the amount and speed of protein adsorption first. However, a further increase in the hydrophilicity of the end-grafted polymers results in the increase in the amount and speed of protein adsorption. This phenomenon is easier to be observed in the end-grafted polymer systems with lower grafting density and longer chain length. In addition, the investigation of the chain conformation of the end-grafted polymers reveals that the end-grafted polymers with mediate hydrophilicity have relatively small size difference along the parallel and perpendicular directions to the substrate, and these end-grafted polymers have relatively wide height distribution. Such characteristics favor covering the space above the hydrophobic substrate and thus can effectively resist protein adsorption.