Protein Vesicles as Emerging Platforms for Drug Delivery, Vaccines, and Immunotherapy

Protein vesicles are spherical, hollow structures made entirely of folded proteins, fusion proteins, or polypeptides. Their intrinsic biocompatibility, nontoxicity, structural tunability, and cargo-loading capacity make them promising candidates for diverse biomedical applications. Although diverse forms of protein-based carriers have long been employed in drug, gene, and vaccine delivery, as well as in artificial antigen-presenting cells, vesicle architectures provide distinct advantages over free proteins, including enhanced stability, targeted delivery, and controlled release. We summarize recent advances in engineering protein vesicles and assess their current status within the broader landscape of synthetic vesicles in biomedicine. By comparing protein vesicles with liposomes, polymersomes, and virus-like particles, we highlight the limitations of conventional systems and underscore the unique benefits of protein-based assemblies. We further examine the emerging applications of protein vesicles in therapeutic delivery, diagnostics, and immunotherapy and discuss future directions needed to advance protein vesicle technologies toward clinical translation.