Application of Phage Biotechnology in Nanobiotechnology

Introduction

The main purpose of recombinant biotechnology is to mimic and improve natural biomolecule production in vitro. This production, coupled with genetic engineering, is making biomolecules more appropriate for in vitro study or in vivo application. Recombinant and engineering technologies involving either DNA or protein can produce only one entity at a time while phage display is the only technology linking DNA and protein. Hybrid phage recombinant and/or engineered contains at the same time the DNA and its protein meaning linkage of genotype to phenotype (Smith, 1993). Purification and preparation of recombinant protein is one of the most difficult tasks in molecular biology. Phage has been assimilated into a plasmid and can be easily purified through the sucrose or cesium chloride gradient (Vidaver et al., 1973). Moreover, the amplification of phages is easily done through rounds of infection of the host. This unique functional features of wild type and hybrid phages attest to their value as tools for the development of a platform for nanotechnology application. Nowadays phage display is used to select important peptide(s) binding to any fixed (immobilized) target. Hybrid phage becomes a platform while the target can be assimilated to nanoparticles. Peptides have the potential to initiate the synthesis, assembly and orientation of nanomaterials (Merzlyak & Lee, 2006). For the past 3 decades this technology has been done using DNA phages (Jespers et al., 1996; Parmley & Smith, 1988). Typically DNA phage has a head and tail with a double-stranded DNA block. DNA-based genotype replicates with the typical proof reading activity of its putative polymerase (Tran et al., 1997). The main goal of a phage display library is to apply molecular evolutionary to biotechnology, leading to the creation of biomolecules with great variety of functionalities. The diversified library is obtained by a combinatorial approach which is diminished by the correction of the DNA polymerase. This can be overcome by using the promiscuity features of RNA polymerase and/or an RNA-based system. Nothing is known about display system based on RNA phage. RNA phages have been purified from animal and human sewages (Abedon, 2008) and can be used to increase the diversity of such library. RNA-based replication system would generate diverse peptides as molecular linkers and synthesizers and assemblers better for nanoparticles which aggregate during high-throughput synthesis than any other system. In this review we not only focus the application of RNA phage in nanobiotechnology, but also on the concepts for the technical implementation of evolutionary strategy to this novel important field.