Bacteria adhesion on the surface of biomaterials and following biofilm formation are important problems in
biomedical applications. The charged antibiotics with small molar mass can hardly deposit alternately with polymers intomultilayered films to load the drug. Herein, the (poly(acrylic acid)-gentamicin/poly(ethylenimine))n ((PAA-GS/PEI)n)multilayer film was designed and constructed via a layer-by-layer self-assembly method. Low molar mass GS cations were firstcombined with polyanion PAA and self-assembled with PEI to form multilayer films showing exponential growth behavior. TheGS dosage could be adjusted by changing the layer number of films. Furthermore, the thermal cross-linking method was used tocontrol the release rate of GS in PBS buffer. Owing to the diffusion of GS, a zone of inhibition of about 7.0 mm showed theefficient disinfection activity of the multilayer film. It could also be seen from the biofilm inhibition assay that the multilayer filmeffectively inhibited bacterial adhesion and biofilm formation. As the drug loading dosage was 160 μg/cm2, the multilayer films
showed very low cytotoxicity against human lens epithelial cells. The present work provides an easy way to load GS intomultilayer films which can be applied to surface modification of implants and biomedical devices.