Filamentous Viruses as Building Blocks for Hierarchical Self-Assembly toward Functional Soft Materials

This review describes the utilization of M13 phage, one of the filamentous viruses, for the development of novel functional soft materials. Traditionally, M13 phage has been widely used as a scaffold to display peptides or proteins on the surface of M13 phage through genetic engineering. This technology is well known as "phage display", and generally used nowadays for the construction of peptide or protein libraries on M13 phage surfaces to identify peptides or proteins with desired functions. Recently, construction of hierarchical assembled structures composed of M13 phage as a building block has generated great interest as a means of using the excellent properties of M13 phage for the development of novel classes of soft materials. In this case, liquid crystalline formation of M13 phage is effectively used to fabricate structurally regulated assemblies. Further combination of the phage display technique and liquid crystalline formation widely expands the applicability of M13 phage to various fields such as devices, sensors, and biomedicines. Such approaches to M13 phage should contribute to novel attractive opportunities for next-generation soft materials for science and technology.