UTTAR PRADESH JOURNAL OF ZOOLOGY

Next-generation nanocarriers offer promising solutions to the persistent challenges of disease control, drug inefficiency, and antimicrobial resistance in aquaculture. This review synthesises current knowledge on three key platforms: liposomes, bacterial ghosts (BGs), and chitosan nanoparticles and evaluates their potential as smart drug and vaccine delivery systems for fish and shellfish. Liposomes, with their phospholipid bilayer architecture, enable the encapsulation of both hydrophilic and hydrophobic molecules, improving drug stability, uptake, and targeted delivery while reducing environmental discharge, as demonstrated for oxytetracycline delivery in Artemia franciscana and therapeutic transport in zebrafish. Chitosan nanoparticles, produced by ionic gelation with sodium tripolyphosphate, exhibit mucoadhesive, biodegradable, and intrinsically antimicrobial properties; their nanoscale size, positive surface charge, and pH-responsive release behavior enhance oral and immersion-based delivery of antibiotics, vaccines, and immunostimulants in aquaculture species. Bacterial ghosts, generated by controlled expression of bacteriophage lysis gene E in Gram-negative bacteria, retain native surface structures and form nanoscale membrane pores that support high drug-loading capacity and enzyme-responsive intracellular release, while simultaneously acting as potent immunostimulatory carriers. Collectively, these three systems address critical limitations of conventional chemotherapeutic delivery by improving bioavailability, site-specific targeting, and immune modulation. The review also highlights current methodological advances, identifies constraints related to scalability, stability, and biosafety, and outlines future research priorities for integrating these nanocarriers into practical, species-specific, and route-optimised therapeutic strategies to support sustainable aquaculture and mitigate antimicrobial resistance.