by Abul K. Tarafder, Miles Graham, Luke K. Davis, Shawna Pratt, Jan Böhning, Pavithra Manivannan, Zhexin Wang, Camila M. Clemente, Aaron Weimann, R. Andres Floto, Raymond J. Owens, George A. O’Toole, Philip Pearce, Tanmay A. M. Bharat All bacterial biofilms contain an extracellular matrix rich in filamentous molecules that self-associate, conferring emergent properties to bacteria, including antibiotic tolerance. Pseudomonas aeruginosa is a human pathogen that forms biofilms in diverse infectious settings, where the upregulation of a filamentous bacteriophage Pf4, has been shown to be a key virulence factor that protects bacteria from antibiotics. Here, we modeled biophysical characteristics of biofilm-linked liquid crystalline droplets formed by Pf4, which predicted that sub-stoichiometric phage binders had the ability to disrupt liquid crystals by changing the surface properties of the phage. We tested this prediction by developing nanobodies targeting the outer surface of the Pf4 ph