Protein cages as theranostic agent carriers

Abstract

Protein cages can be engineered to tailor its function as carriers for therapeutic and diagnostic agents. They are formed by self-assembly of multiple subunits forming hollow spherical cage structures of nanometer size. Due to their proteinaceous nature, the protein cages allow facile modifications on its internal and external surfaces, as well as the subunit interfaces. Modifications on the internal surface allow conjugation of small molecule drugs or contrast agent while modifications on the external surface allow conjugation of various ligands including targeting ligands. The subunit interaction is of special interest in engineering controlled release property onto the protein cage. Two different protein cages, E2 protein and ferritin, are described. © 2013 Springer-Verlag.