C hapTer 11 nanomaterials and nanotechnologies
470
and then analysing them for specific markers using biosensors or
other technologies, such as light-based devices, and communicating results. Doing so requires many nanoscale technologies as well
as understanding how gases and fluids behave at tiny sizes.
A characteristic of a nanosized diagnostic device is that tiny
channels and reservoirs are needed for the sampled gases and
fluids. The latter also must normally be moved around within
these tiny channels. Fluid movements at these scales are quite different than are normally understood at the macroscale, are not
well understood and there are many problems in inducing movements. The field of nanofluidics addresses these many issues. Specific
approaches based on electrophoresis (electrically induced movements) are interesting here, as are other techniques. A variety of
nanoscale biosensor, nanoelectronic, and communication devices
are necessary as well.
Drug delivery involves transporting drugs to specific targeted sites
within the body, a fundamental task in medicine and health; this
has long been a huge area of development and research. Current
delivery systems are well developed, and include oral, nasal, intravenous, pulmonary, and mucosal administration. Specific conditions such as diabetes largely dictate the most effective kinds of
delivery. There are many delivery problems with drugs. They can
exhibit signs of bioincompatibility, lack of stability, or poor solubility or adsorption characteristics. Some peptides and proteins, for
example, degrade in a biological environment, which in turn limits
their efficacy. Each year many new drugs are developed that are not
water-soluble. This restricts their use because delivery to targeted
locations is difficult and their bioavailability is limited. One hope
is that when these drugs are in nanoparticle form, they can be delivered more readily without degrading and that their bioavailability
will be increased.
Nanomaterials promise to play a significant role in new delivery
systems because of the functionalization possibilities associated
with their particle types, size and distribution, surface areas and
charges, and other characteristics. Nanoparticulate-drug conjugates
hold great interest. Very small nanoparticles are thought to be less
likely to cause blockages in even the smallest vessels of the circulatory system (such as capillaries, arterioles, and venules) than larger
ones and also less likely to exhibit a form of sedimentation. Penetration is easier, as is the endocytosis (cellular uptake) process.
Nanomaterials can also be used primarily as carrier vehicles. Polymeric coatings are particularly interesting. They hold the promise
470
and then analysing them for specific markers using biosensors or
other technologies, such as light-based devices, and communicating results. Doing so requires many nanoscale technologies as well
as understanding how gases and fluids behave at tiny sizes.
A characteristic of a nanosized diagnostic device is that tiny
channels and reservoirs are needed for the sampled gases and
fluids. The latter also must normally be moved around within
these tiny channels. Fluid movements at these scales are quite different than are normally understood at the macroscale, are not
well understood and there are many problems in inducing movements. The field of nanofluidics addresses these many issues. Specific
approaches based on electrophoresis (electrically induced movements) are interesting here, as are other techniques. A variety of
nanoscale biosensor, nanoelectronic, and communication devices
are necessary as well.
Drug delivery involves transporting drugs to specific targeted sites
within the body, a fundamental task in medicine and health; this
has long been a huge area of development and research. Current
delivery systems are well developed, and include oral, nasal, intravenous, pulmonary, and mucosal administration. Specific conditions such as diabetes largely dictate the most effective kinds of
delivery. There are many delivery problems with drugs. They can
exhibit signs of bioincompatibility, lack of stability, or poor solubility or adsorption characteristics. Some peptides and proteins, for
example, degrade in a biological environment, which in turn limits
their efficacy. Each year many new drugs are developed that are not
water-soluble. This restricts their use because delivery to targeted
locations is difficult and their bioavailability is limited. One hope
is that when these drugs are in nanoparticle form, they can be delivered more readily without degrading and that their bioavailability
will be increased.
Nanomaterials promise to play a significant role in new delivery
systems because of the functionalization possibilities associated
with their particle types, size and distribution, surface areas and
charges, and other characteristics. Nanoparticulate-drug conjugates
hold great interest. Very small nanoparticles are thought to be less
likely to cause blockages in even the smallest vessels of the circulatory system (such as capillaries, arterioles, and venules) than larger
ones and also less likely to exhibit a form of sedimentation. Penetration is easier, as is the endocytosis (cellular uptake) process.
Nanomaterials can also be used primarily as carrier vehicles. Polymeric coatings are particularly interesting. They hold the promise