VNPs as Templates for Materials Synthesis - Viral Nanoparticles: Tools for Materials Science and Biomedicine - page 144

protein structures, such as VNPs, for the synthesis of man-made materials
is referred to as biotemplating. The biotemplating approach mimics the

process of Biomineralization is a natural process by which

living organisms produce minerals; proteins orchestrate the formation of
complex and inorganic structures with a high level of control (Bauerlein,
2003; Cusack & Freer, 2008; Hildebrand, 2008; Weiner, 2008). Figure 6.1
depicts some of these fascinating structures.
A range of biological templates have been exploited to direct the
deposition, assembly, and nucleation of inorganic materials. These include
bacterial cell surface layers, also known as S-layers (Sleytr

biomineralization.

et al ., 2004),

nucleic acids (Mirkin ., 1996; Niemeyer, 2001, 2004; Seeman, 2005;

Thaxton & Mirkin, 2004), protein cages (see below), VNPs (this chapter),
and whole organisms such as prokaryotic and eukaryotic cells (Flenniken

et al

et

al ., 2004).

Protein cages are similar to VNPs with regard to their structural
organization. They consist of multiple identical copies of protein subunits
and form a symmetrical cage structure of repeating subunits with a defined
exterior surface and interior cavity. Protein cages, such as the iron storage
protein ferritin (which functions to store iron in the form of iron oxide) or
heat shock proteins (which function as chaperones that prevent protein
denaturation) have been extensively studied and utilized in biomimetic
synthesis. The applications of proteins cages in nanotechnology are beyond
the scope of this topic and the reader is referred to the following reviews
(Flenniken

., 2004; Kowshik et al ., 2002; Peelle et al ., 2005; Sweeney et al

et al ., 2009; Klem et al ., 2005; Uchida et al ., 2007; Whyburn et

al ., 2008).

In the following sections, the utilization of the interior cavity of
icosahedral VNPs for materials synthesis (Section 6.1), material deposition
on the exterior surface of icosahedral VNPs (Section 6.2), mineralization
of the exterior and interior surface of the rod

., 2008; Young et al

(TMV)
(Section 6.3), and nucleation of nanocrystal wires using genetically
engineered M13 phages (Section 6.4) will be discussed. At the end of the
chapter, a table is provided that summarizes all the different materials that
have been synthesized using VNPs as scaffold (Table 6.1).

Tobacco mosaic virus

6.1SIZE-CONSTRAINEDSYNTHESISOFINORGANIC
MATERIALSWITHINTHEINTERIORCAVITYOFVNPs

The first efforts to utilize VNPs for materials synthesis were carried out
in 1998 by the researchers Douglas and Young (Montana State University,