Overview of the Manifold VNPs Used in Nanotechnology - Viral Nanoparticles: Tools for Materials Science and Biomedicine - page 23

.1.. enveloped viruses

Enveloped viruses are common among animal viruses. virus (RV),

for one, is an enveloped virus utilized in nanotechnology. The capsid
structure is icosahedral with

Rubella

= 4 symmetry. A lipid bilayer forms an
additional structural layer (the envelope) around the capsid (Frey, 1994).
The envelope is a piece of the host cell lipid membrane that the particles
acquire when they exit the cell by a mechanism termed budding.
To date, few enveloped viruses have been utilized in nanotechnology,
primarily because generating the quantities of material required is more
feasible using non-enveloped viruses, and because non-enveloped capsids
are generally more stable. Nevertheless, efforts have been made using
enveloped VNPs for the development of novel nanoscale diagnostic devices
(Fischlechner

T

et al ., 2005, 2006, 2007; Toellner et al ., 2006) (discussed in

Chapter 7).

.1.. Complex structures

Many bacteriophages have complex structures. For example, particles
of the bacteriophages HK97, P22, and T7 consist of an icosahedral head
(capsid) coupled to a tail. The tail is a hollow structure through which the
bacteriophage's nucleic acid is injected into the host cell after attachment.
The tail structure can be large and complex, or small and simple.
For HK97, P22 (Kang

., 2005, 2006) the
capsids alone have been utilized as platforms in nanotechnology. Besides the
capsids, researchers have also undertaken approaches in which components
of the tail assembly of the phage T4 were employed. The tail of T4 is complex
in that it consists of both a hollow tube and an additional cup structure
(Fig. 2.8). The cup structure is the connecting portion between the tube and
the capsid. Genetic and chemical engineering of the cup structure allowed
the accommodation of gold nanoclusters and metal complexes within
the cup-shaped space (Koshiyama

et al ., 2008), and T7 (Liu et al

et al ., 2008; Ueno et al ., 2006). These

heterostructures may find applications as oxidative catalysts.

. ICoSAhedrAl VnPs

..1 Brome Mosaic Virus : A Plant Virus

BMV is a plant virus from the family Bromoviridae . It infects about 60 genera

within the Gramineae , including maize and barley plants, in which it causes