From Cloning Vectors to Phage Display: Engineering Principles and Translational Applications of Bacteriophage Display Platforms.

Bacteriophage technologies have evolved from classical cloning vectors into programmable platforms for genome engineering and molecular selection. Phage display couples a surface-presented binding phenotype to its encoding genotype, enabling iterative selection, sequence recovery, and optimization of peptides, antibody fragments, and other protein binders. This review links phage morphology, genome organization, infection strategy, host defense, and engineering method to practical platform choice. It compares λ, N15, M13, and T7 systems; examines biopanning bias and candidate developability; and evaluates artificial intelligence-assisted, sequencing-guided, and structure-guided workflows. Vaccine applications are considered alongside constraints arising from anti-phage immunity, antigen density, route of administration, and repeat dosing. Progress will depend on experimentally validated closed-loop workflows that integrate library design, selection, high-throughput analytics, structural characterization, and early manufacturability assessment.