Bacteriophage nanoparticles: an emerging modular delivery platform.

Nanoparticles are now central to many drug and vaccine delivery strategies, but most require reformulation for each application. Bacteriophage‑derived nanoparticles offer a genetically encoded, structurally defined, and modular alternative. This review organizes recent advances along three tunable axes - scaffold, surface, and cargo - and highlights hybrid phage-polymer/lipid/inorganic constructs that expand stability, targeting, and loading. We survey applications from multivalent vaccines and oversized gene transfer to precision microbiome editing, and outline translational hurdles. Phage-derived products are approaching translation, with virus-like particle-based vaccines and CRISPR-enhanced antimicrobial phages in clinical trials. Finally, we preview emerging opportunities, including AI‑guided capsid and receptor‑binding protein design, cell‑free phage synthesis, and standardized 'reference' phage chassis that can be combined with traditional nanoparticles, positioning phage nanoparticles as reusable, plug-and-play nanomedicines.