Protamine – A Review on an Oligonucleotide-Binding Peptide Applied in Nanopharmaceuticals including Vaccines

In our modern days, macromolecular biomolecules are dethroning classical small molecule therapeutics because of improved targeting and delivery properties. Protamine – a small polycationic peptide represents such a promising candidate. In nature, it binds and protects DNA against degradation during spermatogenesis due to electrostatic interaction between the negatively charged DNA-Phosphate backbone and the positively charged protamine. Researchers are mimicking this technique in order to develop innovative nanopharmaceutical drug delivery systems, incorporating protamine as carrier for biologically active components such as DNA or RNA. The first key part of this review highlights ongoing investigation in the field of protamine-associated nanotechnology, discussing the self-assembling manufacturing process and nanoparticle engineering. Immune-modulating properties of protamine are referred which lead to the second key part protamine in novel vaccine technologies. Protamine-based RNA delivery systems in vaccines (some of them belong to the new class of mRNA-vaccines) against infectious disease and their use in cancer treatment are reviewed and an update on the current state of latest developments with protamine as pharmaceutical excipient for vaccines is given.