Biomedical Engineering Reference
In-Depth Information
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Scheme 4.18
Synthesis of a PEI-conjugated SNT.
attractive tools in various biomedical applications, such as in drug or gene
delivery vehicles. To achieve efficient gene delivery, the surface of the SNT
must be rendered positive by conjugating cationic materials. Namgung et al.
functionalized SNTs with magnetic-fluorescence nanocomposites and LMW
branched PEI to construct a device (BPEI-SNT) as a gene carrier and a MRI
agent (Scheme 4.18).
124
In vitro transfection results showed that the transfec-
tion efficacy of BPEI-SNT was much higher than BPEI1.8k, and 46 times
higher than that of bare SNT in HeLa cells.
Quantum dots (QDs) have the potential to serve as photostable beacons to
track siRNA delivery, which is fast becoming an attractive approach to probe
gene function in cells. Zhao et al. synthesized CdSe/ZnSe QD nanoparticles
coated with b-CD coupled to amino acids with different surface charges
through direct ligand-exchange reactions and used them to deliver siRNA
(Scheme 4.19).
125
Compared
with
existing
transfection
agents,
the
gene-
silencing
efficiency
of
the
modified
QDs
was
slightly
improved
for
the
HPV18
E6
gene
in
HeLa
cells.
These
findings
suggest
that
the
QD
Scheme 4.19
Schematic illustration of the formation of QD nanoparticles coated
with b-CD coupled to amino acids and QD-siRNA complexes.
