A multiply active antimicrobial network coating has been synthesized that contains nanophase-separated poly(ethylene imine) units and hydroxyl groups in the surrounding matrix. Silver nanoparticles can easily be loaded into the PEI phase and the hydroxyl groups of the matrix can be separately modified with polyethylene glycol. The resulting coating is an antimicrobial silver ion release system (Figure bottom-TEM image) with a contact-killing and microbe-repelling surface (Figure top-AFM image).