Biomedical applications of viral nanoparticles in vaccine therapy

Viral nanoparticles (VNPs) are versatile systems for the delivery of vaccines and other therapeutic agents for the treatment of diseases such as cancer or those related to the immune-system, degenerative diseases, and infections caused due to agents like viruses, bacteria, and fungi. Additionally, the VNPs are also used in molecular diagnostics, in the development of films and arrays for applications in electronics and tissue engineering, the design of data storage devices, and devices for tissue-specific imaging and therapy. The ability of viruses and bacteriophages to invade and infect different kinds of host cells empower them as suitable nanocarriers wherein they are able to cross biological barriers that obstruct drug delivery. VNPs are generally produced by genetic or chemical engineering by inserting heterologous sequences or ligands of interest into surface-exposed loops of the capsid protein (CPs). The CPs of viruses are the protein-building blocks that can self-assemble and are inherently biodegradable. The capsids that are generated artificially using the modified version of the CPs are known as virus-like particles (VLPs) to which ligands, peptides, and other agents are conjugated to generate VNPs. VNPs can self-assemble either as discrete structures or may organize themselves into films and arrays. Specific formulations of VNPs loaded with biomolecules such as antibodies and aptamers or biomimetics significantly improve efficacy and function by modulating tissue localization. The potential of VNP-based vaccine therapy is yet to be fully explored and it is expected that it will continue to evolve with more effective design and applicability for the treatment of various diseases.