Playing “Nano -Lego ”: VNPs as Building Blocks for the Construction of Multi -Dimensional Arrays - Viral Nanoparticles: Tools for Materials Science and Biomedicine - page 197

The phenomenon of spontaneous self-assembly of rods at the
polyelectrolyte interface has resulted in useful techniques. Battery electrodes
were fabricated using assemblies of metalized M13 particles organized on
polyelectrolyte films (as discussed in Chapter 6) (Lee .,

2006, 2008). This assembly can also be combined with molding techniques
and 2D patterns of polymeric M13 films can be fabricated (Yoo

et al ., 2009; Nam et al

., 2008).
Multi-layered arrays of VNPs fabricated via electrostatic interactions
offer high tunability and flexibility. The interactions between the VNPs and
charged polyelectrolyes can be modulated by ionic strength and pH; the
array can potentially be disrupted under certain conditions, thus releasing
the VNPs. This may be useful for the development of delivery systems for
biomedical applications (discussed in Chapter 8).

et al

. VnP ArrAy ForMAtIon In SolutIon

Arrays of VNPs can be formed in solution. However, because of multivalency
of VNPs, array formation and growth are difficult to control in solution
and often lead to the formation of aggregates. Nevertheless, few examples
demonstrate VNP network formulation in solution: Two sets of CPMV
particles, each decorated with complementary oligonucleotides, were used
to promote self-assembly in solution via nucleic acid hybridization. The
system is reversible upon addition of a competing oligonucleotide (Strable
et al ., 2004). Arrays of VNPs in solution can also be formed by mixing

biotinylated VNPs with streptavidin (Wang ., 2002).

Hybrid networks of VNPs and inorganic materials have also been
fabricated in solution. Aggregates of CPMV and QDs as well as

et al

Flock

house virus and carbon nanotubes have been generated using covalent

bioconjugation strategies (Portney

., 2005). Non-covalent hybrid
networks have been created using genetically engineered M13 particles.
Here, a phage construct expressing a gold-binding peptide as well as tissue-
specific targeting peptides was mixed with gold. The interaction with
gold led to the formation of a hybrid network that has been utilized for
cell targeting and imaging applications and will be discussed in Chapter 8
(Souza

et al

et al ., 2006).

. ArrAyS oF enVeloPed VnPs

The infection process of enveloped VNPs involves fusion of the viral
membrane with cellular membranes such as the plasma membrane or
the endosomal membrane. Fusion with endosomal membranes is often