PLANT VIRUSES AS A BIOTEMPLATE FOR NANOTECHNOLOGY

Course TeacherDr. T. GANAPATHY

StudentMOHAMMED FAISAL P

Nano Definitions

• Design, engineer, manufacture, or …• Control a process

– at the nanoscale dimension• Atom by atom precise manipulation• Functionalize and monetize properties at the nanoscale

dimension• self-assembly

Scale and Dimension

• Quantum scale dimension– Small things– Short times– Small numbers– Low probabilities

• Heisenberg and Plank got it rightThings happen differently at nanoscale

Viruses as nanomaterials Disease-inducing capabilities of plant viruses has been ongoing for almost 125 years.

In recent years, there has been a re-orientation of virus studies toward the beneficial use.

This switch coincided with the interfacing of the fields of virology with biomimetic chemistry and the development of the tools of molecular biology over the past 30 years.

From the chemist’s point of view, viruses are captivating for the following reasons

Their size range, from approximately 10 nm to more than a micron, is unique for organic structures characterized at atomic resolution

They can be found in a variety of distinct shapes and with a variety of properties (such as varying sensitivities to pH, salt concentration, and temperature)

They represent the ultimate examples of self-assembly and polyvalence.

Self Assembled Nanostructures?

They have large surface areas, which allow for the display of many copies of the same molecule or many different molecules, without concerns of steric crowding

They can be made in quantity

CAPSIDMany plant viruses assemble capsids with precise 3D structures providing nanoscale architectures that are highly homogeneous and can be produced in large quantities

Capsids are amenable to both genetic and chemical modifications allowing new functions to be incorporated into their structure by design

For many viruses, in vitro self-assembly mechanisms of coat protein (CP) monomers, in the presence and absence of the nucleic acid, into intact and stable viral like particles (VLPs) have been observed

for example BMV, CCMV, and tobacco mosaic virus (TMV)

(Cuillel et al., 1898; Miller et al., 2007)

Nano-Bio-Info

Nano

Bio Info

Concept by Robert Cormia

Nano-Bio

• Using protein / viral complexes and DNA to self-assemble devices, and novel function, into biomechanical systems

Earth’s early nanostructures ~ 2 billion years ago

The three capsid surfaces, the interior surface, the exterior surface, or the interface between coat protein subunits, can be independently functionalized to produce multi- functional biotemplates.

PLANT VIRUS CAPSIDS AS REACTION VESSELS

Two different approaches can be taken to entrap guest molecules within the capsid interior.

In one approach, the guest molecules are entrapped during the capsid assembly process.

In the second approach, the guest molecules are entrapped within the already preassembled capsid architectures.

Protein conjugation strategies

(Andrew Lee et al., 2009)

Certain plant viruses and nanotechnology

Plant virus capsids used as biotemplates for nanomaterials and their application in biomedicine

Viruses Nanomaterials Reference

Brome mosaic virus (BMV)

Au nano particles Chen et al., 2006

CdSi/ZnS semiconductor

Endo et al., 2007

Iron oxide nanoparticles Haung et al., 2007

Carnation mottle virus (CarMV)

2D/3D Patterning/array formation

Lvov et al., 1997

Cowpea chlorotic mottle virus (CCMV)

Polymer loading/encapsidation

Chang et al., 2008

2D/3D Patterning/array formation

Klem et al., 2003

Enzyme nanoreactor Comellas-Aragone et al., 2003

Viruses Nanomaterials/ Biomedical

applications

Reference

Cowpea cholrotic mottle virus (BMV)

Imaging agents Allen et al., 2005

Targeting Suci et al., 2007a

Biodistribution Suci et al., 2007a

Cowpea mosaic virus (CPMV)

Chemical conjugation Arora and Kirshenbaum. 2004

Drug delivery platforms Raja et al., 2003

Imaging agents Lewis et al., 2006

Viruses Nanomaterials/ Biomedical

applications

Reference

Tobacco mosaic virus (TMV)

Surface modifications Miller et al., 2007

Liquid crystals Fowler et al., 2003

Nanowires/mineralization Bittner, 2005.

Patterning/arrays

Dujardin et al., 2003

Turnip yellow mosaic virus (TYMV)

Fluorescent labeling/sensor development

Barnhill et al., 2007

1. Tobacco mosaic virus (TMV)

Microarray consisting of tobacco mosaic virus particles

TMV exhibits different properties of the exterior and interior surface,

Different amino acid compositions,

Allow spatial and controlled deposition of metals.

Deena Awad, 2010

Deposition of TMV in an aligned coating.

Deena Awad, 2010

Stepwise preparation of nanowires from TMV-coated substrate. a) Model of a TMV-coated sub- strate plate, which is then placed in b) a glutaraldehyde solution to crosslink the TMV fibers. The resulting complex is then placed into a c) solution containing gold nanoparticles for conjugation onto the cros- slinked TMV. Finally, the crosslinked, conjugated TMV in placed in a silver ion-hyrdoquinone solution for enhancement of the TMV nanowires.

TMV nanowires

The TMV modified devices demonstrated charge–discharge operation up to 30 cycles reaching a capacity of 4.45 μAh cm−2

Exhibited a six-fold increase in capacity during the initial cycle compared to planar electrode geometries.

Genetically modifying the virus to display multiple metal binding sites allows for electroless nickel deposition and self-assembly of these nanostructures onto gold surfaces.

Structural location of the TMV1cys mutation

TEM image of wild-type viruses

Schematic of the microbattery layers.

Schematic representation of the TMV assembly and nickel coating process: the TMV binds on the gold surface (step 1), it is activated with a palladium catalyst (step 2) and it is finally coated with nickel (step 3).

TMV assembly and nickel coating process

Initial discharges of cells with and without TMV coating

2. Cowpea mosaic virus (CPMV)

Cysteine residues engineered on CPMV on the protruding loop shown here in red, which have a tendency to aggregate without the presence of reducing agents.

(Andrew Lee et al., 2009)

Multifunctional bionanoparticles for in vivo imaging and drug delivery

CPMV for drug delivery. Therapeutics is loaded in the capsid interior and homing domains (Int 8) are attached for the targeting of cancer

cells. Once the virus particles are attached to the cells, they will be endocytosed and the drugs will be released once the virus particles

are degraded in the cytosol

RCMNV (Red clover necrotic mosaic virus)

The RCNMV capsid, consisting of 180 copies of a single protein,

Icosahedral structure with diameter of approximately 36 nanometres.

The main property of the RCNMV that makes it useful as a nanotemplate.

It has a hollow 17 nanometer wide interior, which can contain up to 2000 molecules

Insertion of drugs

Drug-delivery system

RCNMV is to be used in a drug-delivery system within the human body

controlled by placing small proteins on the surface of the capsid

signal-peptides which are attracted to specific predetermined cells

The human blood vessels contain concentrations of calcium high enough for automatic sealing of the capsid.

This leads to emission of the content of the capsid as soon as it has entered the desired cell.

Such a target specific delivery of drugs will greatly reduce side effects of all kinds of chemotherapy.