Biomedical Engineering Reference
In-Depth Information
FIGURE 5.5 Schematic diagram of an NM for (A) drug delivery and (B) targeted drug delivery.
Courtesy of Ocean NanoTech. (For color version of this figure, the reader is referred to the online
version of this topic)
tumors. Repression of HER-2/neu was observed in many studies indicating that
HER-2 is an excellent target for developing anticancer agents specific for HER-
2-upregulated cancer cells. It has been used as target with CdSe quantum dots
(QDs) that had been conjugated with monoclonal anti-HER-2 antibody. 86 The
following protocol was designed in preparing HER-2-targeted drug delivery.
Procedure for HER-2-targeted drug delivery
(1) Take 1 nmole of carboxyl-surface-modified iron oxide nanoparticles (IONPs)
dispersed in water or appropriate buffer such as borate buffer at pH 7-7.4.
(2) Take 1-5 nmoles of monoclonal antibodies (mAbs) against HER-2 mAb
and dissolve in borate buffer at pH 7-7.4.
(3) Add 50 µL of 0.02 M EDC and 26µL of 8 mM of NHS and mix well for 1-5 min
(optimize the conditions depending upon the NMs and drug to be loaded).
(4) Vortex at RT for 1 h.
(5) Remove unreacted antibody by centrifugation, dialysis, or magnetization of
the magnetic NMs. The centrifugation speed needs to be optimized depend-
ing upon the size of the NMs. The MW cutoff of the dialysis tubing also needs
to be chosen based on the size of the NMs. Magnetization is recommended
for ≥25 nm but not for <25 nm because the process may take more than 24 h.
(6) Load the drugs based on the appropriate protocols for the drug and the NMs.
(7) Resuspend the NMs in the recommended buffer and refrigerate until use.
(8) Characterize the antibody conjugation with agarose gel electrophoresis. The
NMs carrying the covalently conjugated antibody show a retarded migration
compared with the NM ( Figure 5.6 ) that does not carry a conjugated anti-
body. After conjugation of an antibody or a protein or any other biomolecule
to an NM, the gel shows a tailing of the signal that may be attributed to the
Search WWH ::




Custom Search