Biomedical Engineering Reference
In-Depth Information
with drugs do not aggregate nor precipitate when the NMs are properly coated
with amphiphilic polymer as indicated in Chapter 5. Without the proper coating,
the NMs aggregate upon exposure to fresh human whole blood. Such observa-
tions need to be prevented if the NMs are to be used for in vivo applications.
Prior to use for in vivo studies, the toxicology of NMs need to be inves-
tigated including the possibility of adverse effects if these are to be used as
drug nanocarriers.
12,18,25,144,201,202,246,247,322-335
The current level of research and
development of some NMs for drug delivery system is still its infancy that more
studies need to be conducted very thoroughly. Research on the absorption, dis-
tribution, metabolism and elimination (ADME), and drug metabolism and phar-
macokinetics (DMPK) must be further elucidated on nanomaterial drug delivery
systems in the future before these can be fully trusted and launch for human use.
Depending on their functionalization, biodegradable drug nanocarri-
ers can take a number of different paths within tissues during drug deliv-
ery.
144,146,188,290,295,325,336-345
The pharmacokinetics and excretion routes of
these nanocarriers demand exhaustive research to clear the path for their human
applications. The path that the nano-enabled drugs take after entry into the liv-
ing system depends on many factors which were discussed in this Chapter 5.
Imaging properties may be the most useful characteristics of some NMs for
elucidating their ADME and PK during drug delivery. Further investigations on
these properties and other modes of detection are important as the NMs enter
the realm of human consumption.
NMs are now found as components of FDA approved drugs that are already
sold in the market.
312
They are used for easy and efficient delivery of drugs with
enhanced therapeutic effects. A few of these examples were discussed Chapter 4,
Chapter 5, and in Chapter 7. Drugs that are coated polymer NMs and iron oxide
NMs coated with dextran have emerged as very sensitive contrast agents for mag-
netic resonance imaging (MRI).
6,10,53,54,58,66,90-95,97,102-104,120,137,161,169,183,227,289-
295,299,307,312,313,325,346-352
Additionally, several studies in clinical the trials
indicate that cancer drugs have also been loaded in nanoparticles for ease of
delivery.
56,240,276,350
More studies are underway for the specific targeting of these
drugs so that effect on healthy cells can be minimized while focusing the unload-
ing of the drugs on the sick cells such as cancer cells. Other studies have also
focused on the use of NMs for eradicating viral infections which have been one
of the most difficult challenges of the human population during the last century
and into the millennium.
290,295,303,306,309,312
Studies on the use of NMs for the
delivery of vaccines especially those diseases that have no existing vaccines in
the market have also began to be noticed in the literature.
76,89,114,154,174,196,353
9.7 NANOMEDICAL DEVICES
NMs when properly combined with biomolecules have found a wide spec-
trum of applications such as to create novel tissue substitutes, nanorobots, and
nanodevices with significantly improved performances.
39,115,187,255,315,354-356
In
