Biomedical Engineering Reference
In-Depth Information
the AuNPs. The Jurkat cells showed higher uptake for the 50 nm AuNPs than
the PANC1 cell lines
158
as shown by inductively coupled plasma-mass spec-
troscopy. The AuNPs were observed to be non-toxic to Jurkat and PANC1 cells.
Jurkat cells in the presence of 25 nm and 50 nm AuNPs at 10 µg/mL exhibited
a viability of 102% and 93%, respectively at 24 h as compared with controls
(100%); and 99% and 100%, respectively at 48 h.
158
The PANC1 cells showed
viability of 107% and 124% compared with the controls when grown for 24 h
in the presence of 25 nm and 50 nm AuNPs, and 91% and 83%, respectively at
48 h.
158
Thus, at 10 ug/mL concentration, the AuNPs were found to be non-toxic
to the cells in vitro.
158
These observations are critical in the design of AuNPs for
drug delivery or for delivery of NPs for other therapeutic purposes.
For practical purposes, the AuNPs of various shapes and sizes showed
insignificant toxicity as exhibited by the various studies that had been
cited.
142,143,145,146,148,150,153,155,157-159
These studies do not show conflicting
results in both the in vitro and in vivo studies. However, it is still recommended
to continue the toxicity studies in order to learn the possible long-term conse-
quences of AuNPs in animals and in humans.
8.2.4 IOMNP Toxicity
One of the most rapidly growing areas of interest in nanotechnology is in IOM-
NPs or superparamagnetic iorn oxide nanomaterials (SPIONs). The IOMNPs
have found excellent applications in magnetic resonance imaging (MRI), mag-
netic isolation of cells, drug delivery, hyperthermia, and many more.
4,15-17,160-163
IOMNPs are excellent NMs for these applications because of their ease of
manipulation with the use of permanent or electric magnets.
164
IOMNPs are NMs that consist of iron oxide core materials that are usu-
ally coated with biocompatible materials for medical applications. The sur-
faces of the IOMNPs are easily modified to attach different molecules based
on the desired function. The advantage of the IOMNPs over other NMs is the
ease of manipulation with external magnets that can be targeted to the required
area through external magnets.
165
Depending upon the size and the amount of
magnetic material, the IOMNPs can exhibit properties that include superpara-
magnetism, high field irreversibility, high saturation field, and extra anisotropy
contributions or shifted loops after field cooling.
166
Today, studies on the medi-
cal applications of the IOMNPs have gone to include reduction of the amount
of cytotoxic drug for the systemic distribution thereby eliminating possible side
effects and decreasing the drug through more efficient and localized delivery
of the drug.
The IOMNPs come in two forms: 1) magnetic particle core composed of
magnetite, Fe
3
O
4
, or maghemite, γ-Fe
2
O
3,
coated with a biocompatible poly-
mer
132
or 2) a biocompatible polymer in which the IOMNPs are precipitated
inside the pores.
165,167
The coating can be an amphiphilic polymer that is used to
make the IOMNPs water soluble and at the same time protects the nanoparticle
