An investigation on the biological and corrosion response of PEI coating on the AZ31 alloy

AZ31 Mg alloy surface was coated with polyethyleneimine (PEI) coating with anticorrosive properties in a two-step process to improve corrosion resistance. In the first step, alkaline passivation was followed by a PEI cationic polymer dip coating based on chemical and electrostatic interactions. AZ31 Mg alloy coated with PEI showed better corrosion resistance in PBS than uncoated alloy, based on electrochemical tests including potentiodynamic polarization and electrochemical impedance spectroscopy. Biocompatibility and in vitro cell behavior tests revealed good adhesion and proliferation in the presence of amine groups in the PEI structure. Furthermore, the antibacterial research showed that PEI-coated AZ31 had a great antibacterial activity. These findings suggest that PEI-coated AZ31 Mg implants are suitable for orthopedic applications as bioactive and protective biomaterials.