Antibiofilm Peptides Revisited: From Biofilm Models and Metrics to Mechanisms and Translation.

Biofilm-associated infections contribute substantially to the antimicrobial resistance-related burden by promoting persistent, difficult-to-treat infections. Antibiotic failure often reflects biofilm recalcitrance (tolerance and persistence) and, in some contexts, the enhanced selection and dissemination of resistance. To overcome this burden, antibiofilm peptides (ABPs) are emerging as a versatile solution. ABPs can inhibit biofilm development, weaken established biofilms, and synergize with existing antimicrobials. This review highlights current biofilm models and susceptibility end points, emphasizing how experimental design and readout selection shape conclusions about ABP activity and comparability across studies. We describe ABP discovery, the sequence-property features that drive activity, and outline key modes of action. These include reprogramming biofilm-associated regulatory pathways, targeting conserved nucleotide signaling networks such as guanosine tetraphosphate (ppGpp) and cyclic di-GMP (c-di-GMP), matrix-directed effects, and biofilm-specific tolerance and resistance mechanisms that may limit ABP durability. Finally, we briefly discuss translational considerations and selected clinical and industrial use cases for ABPs, emphasizing the importance of improving and assessing their stability, delivery, and selectivity under physiological and industrially relevant conditions.