Antiviral peptides as emerging therapeutic agents: a narrative review of engineering strategies, delivery innovations, and clinical perspectives

Background. Viral infections remain a major global health threat despite advances in vaccines and antiviral drugs due to the rapid emergence of resistance and new viral pathogens. Antiviral peptides (AVPs) are promising broad-spectrum therapeutic agents because of their structural diversity and multiple biological activities. Aim. The aim of this narrative review is to summarize current knowledge on antiviral peptides, focusing on their classification, mechanisms of action, molecular engineering strategies, delivery systems, and clinical perspectives. Material and methods. A narrative review of recent peer-reviewed literature on antiviral peptides, engineering techniques, and modern drug-delivery approaches, including liposomes, polymer nanoparticles, and mucosal systems, was conducted. Results. AVPs act at multiple stages of viral replication, including inhibition of viral attachment and fusion, disruption of viral envelopes, interference with intracellular replication, and modulation of immune responses. Engineering strategies such as cyclization, PEGylation, D-amino acids, and lipidation improve stability and pharmacokinetics, while novel delivery systems enhance bioavailability. Clinical translation is limited by short half-life, toxicity, cost, and regulatory challenges. Conclusions. Antiviral peptides are promising broad-spectrum therapeutics, and further interdisciplinary research is needed to enable their clinical application.