Biomedical Engineering Reference
In-Depth Information
Extravasation of NMs is favored because of the presence of large (several
hundred nanometers) vascular fenestrations on newly formed angiogenic ves-
sels. The NMs can have surface modifications with materials such as a polyeth-
ylene glycol (PEG) that make the nanocarriers “stealth” eluding uptake by the
RES; achieving sufficient prolonged circulation time that improves the chances
of reaching and attacking the tumor.
3,4,10,52,71,89,93,167,235,289,290,346,384,403-407
Success in chemistry and materials science yielded several other NMs for drug
delivery that includes polymer conjugates, polymer micelles, and dendrim-
ers.
66,82,86,95,97,102,110,154,192,293,303,306,319,352,377,380,399,408,409
Hence, at the onset of
NMs applications as drug delivery systems, no active mechanisms of disease site
location and therapy were involved. The second generation involves nanodrug
delivery systems that are equipped with targeting functionality through careful
combination of engineering, protein chemistry, and molecular biology. The active
mechanism may result from 1) targeting moiety on the nanocarriers through the
presence of specific molecular recognition molecules to receptors that are over-
expressed on the tumor cells or adjacent blood vessels (such as Ab conjugated
NMs) or 2) a possibility for active/triggered release of the payload at the diseased
location (e.g. magnetic nanoparticles).
64,65
Thus, the current NMs for drug deliv-
ery are superior to their precursors through the use of targeting moieties, possi-
bility of remote activation, and environmentally sensitive components, bringing
additional degrees of sophistication in design that promises increased success in
accomplishing the intentions. The presence of logic embedded vectors (LEVs)
add further assurance for optimum accomplishment of the intended applica-
tions.
410
LEVs are specifically engineered to avoid biological barriers, where the
functions of biorecognition, cytotoxicity, and no susceptibility to biobarrier are
eliminated through careful manipulation and efficient engineering.
411
By design,
the LEV is a drug delivery system that will be able to go through the vasculature
after intravenous administration, to reach the desired tumor site at full dosage of
the drug, and to selectively kill cancer cells with the loaded drugs and at the same
time have minimal harmful side effects.
412-414
These LEVs are, theoretically as
of now, useful also for advanced therapy and imaging with immense potential for
enhanced drug delivery that will bear a high impact on the future of personalized
medicine that is one of the priorities of nanopharmacology.
As all other areas of medicine that had been so far discussed, pharmacology
has been revolutionized by this nanotechnology era that sprouted at the end of
the twentieth century and has boomed toward the beginning of the twenty-first
century.
N
anomaterial research and development continue to be engineered in
various was to diagnose disease and health conditions; to recognize pathogenic
infections; to locate, attach, and penetrate target tissue or structures or patho-
gens; and dispense the payload of drugs or biological compound to the targeted
regions of the body-the area now known as nanopharmacology.
Nanopharmacology, although still in its early stages, has witnessed an over-
hauling of the conventional pharmacology.
10,89,95-97,120,161,296,297,311,341,346,408
This overhaul are manifested through drug engineering design and develop-
ment, manufacture of nano-enabled drug or drug carriers, and the application
