Polyethylene glycol (PEG) was approved by the US Food and Drug Administration for internalization in the human body . It is used as an anti-biofouling material to provide a hydrophilic environment on a substrate surface. Although the mechanism is not fully understood, it has been suggested that the hydrophilic surfaces could act as a good anti-biofouling barrier and that the protein and cell resistance of surface-immobilized PEG could be attributed to the large exclusion volume, high mobility, and steric hindrance effects of the highly hydrophilic layer . PEG was shown to reduce protein adsorption and platelet adhesion in a blood-material interface . A study synthesized a methacryloyloxydecyl phosphate PEG for the prevention of Streptococcus mutans adhesion on hydroxyapatite and found that its inhibitory effect on bacterial binding was diminished by saliva protein .