Protein Cage Nanoparticles as Delivery Nanoplatforms.

Protein cage nanoparticles are made of biomaterials, proteins, and have well-defined cage-like architectures designed and built by nature. They are composed of multiple copies of one or a small number of chemically identical subunits having a highly uniform nano-size and symmetric structure. Protein cage nanoparticles have genetic and chemical plasticity amenable to simultaneously introducing multiple cell-specific targeting ligands, diagnostic agents, and their corresponding therapeutic agents at desired sites depending on its purpose. A wide range of protein cage nanoparticles, such as ferritin, lumazine synthase, encapsulin, and virus-like particles, has been extensively explored and utilized in biomedical fields as effective delivery nanoplatforms of diagnostics and/or therapeutics. Highly biocompatible and plastic protein cage nanoparticles may provide a new paradigm for developing simple, but versatile in vivo delivery systems.