Virus-like particles (VLPs) are highly structured protein complexes that resemble a native virus capsid ranging 20–800 nm. It is made up of one or more different molecules with the ability to self-assemble and mimicking the form and size of a virus devoid of viral genome and are therefore non-infectious. VLPs in general can be either enveloped or non-enveloped, whereby in vitro assembly typically leads to protein-only shells. Due to the lack of viral genomes, these particles are non-replicative but typically retain the transduction potential of the parental viruses, which may be used for various biomedical applications.
Expression and self-assembly of the viral structural proteins of VLP can be produced in a variety of systems, including mammals, plants, insects, and bacteria. Each expression systems have several advantages such as high yield of expressed proteins, post translational modification, formation of multi-protein on the surface of VLP. VLPs have similar characteristics as nanoparticle and have the ability to mediate more biomedical functions through biotechnological methods. Therefore, VLPs have a significant function in drug delivery, genetic therapy, cellular targeting, and cancer treatment.