In this study, a nanocomposite coating composed of polydopamine,
functionalized poly(3,4-ethylenedioxythiophene) (PEDOT), and
silver nanoparticles (AgNPs) was synthesized through layer-by-layer
deposition. Biomimitic polydopamine and hydroxyl-functionalized PEDOT
were used to enhance the adhesion strength. The deposition of PEDOT
functionalized with zwitterionic phosphorylcholine can contribute
to the antifouling property. After immersion in the AgNO3 solution, Ag+ ions were adsorbed on PEDOT films and further
reduced to form AgNPs spontaneously, which conferred antibacterial
properties on these nanocomposite films. Escherichia coli and Streptococcus mutans were chosen to represent
two common Gram-negative and Gram-positive oral pathogens. We further
conducted inductively coupled plasma mass spectrometry to confirm
that the Ag+ ions released from these nanocomposite films
did not exert adverse effects on the human body. These results suggested
that, when applied to stainless steel orthodontic appliances, these
durable antifouling and antibacterial coatings may be useful for avoiding
bacterial infection.