Engineering protein nanocages as carriers for biomedical applications

Bhaskar, Sathyamoorthy; Lim, Sierin

Smart nanosized materials with high stability, suitable pharmacokinetics and efficient cell permeability for delivering cargo molecules to target cells have been the requirements for an ideal drug delivery system. 1 Advances in the design and fabrication of synthetic carriers such as cationic liposomes, micelles, block copolymers, carbon nanotubes, dendrimers and inorganic nanoparticles are restricted by severe toxicity and low delivery efficiency. 2 Nature-derived nanocarriers are potential alternatives to synthetic ones as they satisfy most of the key features, such as biocompatibility, water solubility and high cellular uptake efficiency with minimal toxicity. 1, 3 Examples of naturederived nanocarriers include protein nanocages such as viruses, ferritin and many others that are formed by the self-assembly of protein subunits, resulting in a cage-like structure. The monodispersed subunits are modifiable through chemical and genetic methods. 3 The key biomedical applications involving the use of protein nanocages that we focus on in this review are therapeutics and diagnostics.