Playing “Nano -Lego ”: VNPs as Building Blocks for the Construction of Multi -Dimensional Arrays - Viral Nanoparticles: Tools for Materials Science and Biomedicine - page 188

have been applied to
design single M13 arrays. In brief, a patterned polydimethylsiloxane (PDMS)
stamp was placed on a wet-spin-coated film of PEG polymers. Solvent-
assisted capillary effects during the drying process result in the formation
of patterns. The pattern is a replica of the stamp features. Nanowells
were

Soft lithographic techniques such as nanomolding

into the film (Fig. 7.16). The wells were functionalized with
antibodies specific for the M13 pIII coat protein, which facilitated capturing
of individual M13 particles within the wells (Fig. 7.16) (Suh

molded

et al ., 2006).

Figure 7.16 (a) Schematic illustration of the experimental procedure. Prior to virus

seeding, the patterned surface was treated with an antibody specific for the pIII
M13 coat protein to promote adhesion of the virus. (b) Atomic force microscopic
images of 700 nm PEG nanowells in (a) height and (b) deflection modes. Scan area
was 15 × 15 . The inset shows the corresponding fluorescent image treated

with the P3 antibody and a FITC-labeled secondary antibody.

µ

m

2

(c) SEM image of an
individual virus array on six wells. Four insets show the captured single virus at
different locations. The arrows indicate the location of the virus. Reproduced with
permission from Suh, K. Y., Khademhosseini, A., Jon, S., and Langer, R. (2006) Direct
confinement of individual viruses within polyethylene glycol (PEG) nanowells, Nano

Lett. , 6 (6), 1196-1201.

7.5.3ImmobilizaionofVNPsUsingBiospeciicInteracions

VNPs can be immobilized on surfaces using biospecific interactions.
Biospecific interactions were used in the above-described example, in
which M13 particles have been captured in nanowells using an antibody
specific for the pIII coat protein (Suh ., 2006). Furthermore, biospecific

interactions used to immobilize VNPs include the biotin-streptavidin
system, Ni-NTA-hexa-His interactions, and nucleic acid hybridization.
The biotin-streptavidin system has been widely used for the construction
of multi-layered arrays of VNPs and will be discussed in Section 7.6.
Immobilization of His-mutant VNPs that display a hexa-His tag can be
achieved via the strong interaction of the hexa-His sequence with Ni-
NTA. This strategy has been used for CPMV and

et al

Q b (Chatterji et al ., 2005,

2006; Medintz et al ., 2005; Udit et al ., 2008) (see also Section 7.5.3).