Agriculture Reference
In-Depth Information
Fig. 10.3 Surface modification of DNA conjugated with nanoparticles with poly-L-lysine (PLL)
that gives positive charge on nanoparticles—DNA complex and which attracts to negative charge
of the cell wall of a plant cell
covalently conjugated to different biotinylated peptides (Chen and Gerion
2004
;
Lagerholm et al.
2004
; Kim et al.
2008
). Several approaches are available for the
conjugation of biomolecules like proteins to nanoparticles, including enzymes or
antibodies. Initially only “nonspecific” adsorption was employed: this can be
achieved by incubating nanoparticles with the protein, which allows the adsorption
of nanoparticles to the proteins by electrostatic attraction or by van der Waals
forces, hydrogen bridges, thiol bonds (from cysteine residues), or amino groups
modified by agents like bis-NHS for the coating on silica nanoparticles (Jana
et al.
2007
). Josephson et al. (
1999
,
2001
) have demonstrated the covalent conju-
gation of magnetic iron oxide nanoparticles with peptides and oligonucleotides.
There are several examples of nanoparticle-protein conjugation, which can be
found in a number of reviews and research papers (Niemeyer
2001
; Ghadiali and
Stevens
2008
).
Yu et al. (
2012
) reported a new method to use ZnS nanoparticles as a gene carrier
for plant gene transfer. The ZnS nanoparticles with a diameter of around 3-5 nm
were modified with positively charged poly-
L
-lysine (PLL) to bind negatively
charged pBI121 plasmid DNA. The ZnS nanoparticles-mediated transformation
of tobacco was carried out via ultrasound-assisted method. The ZnS nanoparticles-
mediated stable gene expression in tobacco plant was observed for the first time.
Cui et al. (
2012
) used polyethyleneimine (PEI)-modified magnetic nanoparticles as
vectors to transfer genes to porcine somatic cells. The PEI-modified Fe
3
O
4
mag-
netic nanoparticles are mixed with pEGFP-N1 in a certain mass ratio and incubated
for 30 min at room temperature; this modified nanoparticles were employed to
transfer the reporter gene into somatic cells, and also the gene delivery efficiency
was examined (Hoshino et al.
2004
) (Fig.
10.3
).
10.2.4 Characterization of Nanoparticles (NPs)
Characterization of NPs is necessary to establish the understanding about synthesis
and conjugation with the biomolecules. The surface characterization normally
includes measuring the particle size, shape, surface charge, and magnetic
