471
of being able to deliver drugs to specified sites and aid in controlled releases upon target triggering mechanisms. Nanocoatings can
allow the use of largely insoluble drugs or potentially ones with
greater activity or even toxicity. Coatings that have been explored
can be quite thin—only several nanometers thick.
For specific conditions such as insulin delivery for diabetics, pulmonary delivery of peptides and proteins are interesting because
of their noninvasive character and provision of large surface areas
with their potential for increased absorptions. Nasal delivery provides direct access to mucosa surface absorption sites, but its efficacy has proven low and potential mucosal damage problematic.
Oral delivery is easy and cost effective, but insulin permeability in
the gastrointestinal track is limited and degradation of the drug can
occur. Nanoparticles can potentially be designed to be biodegradable and biocompatible and more stable within a biological environment; they may well prove effective as bioactive macromolecule
carriers. Polymer-based nanoparticles, such as polyethylene glycol
(PEG) coated polylactic acid (PLA) nanoparticles, are a particularly
interesting area of study for protein delivery. The PEG coating can
help transport the encapsulated protein within and across intestinal
or nasal mucosae. Chemical stability is improved. Nanoparticulatedrug conjugates hold promise for improved insulin delivery.
Despite potential benefits, research is only just beginning into the
many issues surrounding beneficial ways to utilize nanomaterials
for drug delivery. A particularly interesting problem, for example,
surrounds the way various nanoparticle types and forms might
interact with other cells, including the macrophage cells that play a
fundamental role in the body’s immune system by attacking foreign
substances. Seemingly endless numbers of studies have yet to be
done on other issues, including basic efficacy, potentially deleterious side effects, and so forth.
Chapter 2 introduced a few basic ideas about bones in relation
to nanomaterials. Bones are indeed fascinating materials that constantly renew themselves at the cellular level. In bones, the basic
material (hydroxyapatite) is secreted within nanosized collagen
fibers (connective tissue). The body reabsorbs the basic material
and secretes it anew in response to changing demands placed on
the bone as a function of growth, damage, or other factors. These
actions have suggested fascinating interventions for strengthening and repair of damaged or vulnerable bone fabrics through
injections of bioactive nanoscale materials that harden under the
action of body fluids. Target materials are designed to mimic and
Medical and Nanotechnology Pharmaceutical Applications
of being able to deliver drugs to specified sites and aid in controlled releases upon target triggering mechanisms. Nanocoatings can
allow the use of largely insoluble drugs or potentially ones with
greater activity or even toxicity. Coatings that have been explored
can be quite thin—only several nanometers thick.
For specific conditions such as insulin delivery for diabetics, pulmonary delivery of peptides and proteins are interesting because
of their noninvasive character and provision of large surface areas
with their potential for increased absorptions. Nasal delivery provides direct access to mucosa surface absorption sites, but its efficacy has proven low and potential mucosal damage problematic.
Oral delivery is easy and cost effective, but insulin permeability in
the gastrointestinal track is limited and degradation of the drug can
occur. Nanoparticles can potentially be designed to be biodegradable and biocompatible and more stable within a biological environment; they may well prove effective as bioactive macromolecule
carriers. Polymer-based nanoparticles, such as polyethylene glycol
(PEG) coated polylactic acid (PLA) nanoparticles, are a particularly
interesting area of study for protein delivery. The PEG coating can
help transport the encapsulated protein within and across intestinal
or nasal mucosae. Chemical stability is improved. Nanoparticulatedrug conjugates hold promise for improved insulin delivery.
Despite potential benefits, research is only just beginning into the
many issues surrounding beneficial ways to utilize nanomaterials
for drug delivery. A particularly interesting problem, for example,
surrounds the way various nanoparticle types and forms might
interact with other cells, including the macrophage cells that play a
fundamental role in the body’s immune system by attacking foreign
substances. Seemingly endless numbers of studies have yet to be
done on other issues, including basic efficacy, potentially deleterious side effects, and so forth.
Chapter 2 introduced a few basic ideas about bones in relation
to nanomaterials. Bones are indeed fascinating materials that constantly renew themselves at the cellular level. In bones, the basic
material (hydroxyapatite) is secreted within nanosized collagen
fibers (connective tissue). The body reabsorbs the basic material
and secretes it anew in response to changing demands placed on
the bone as a function of growth, damage, or other factors. These
actions have suggested fascinating interventions for strengthening and repair of damaged or vulnerable bone fabrics through
injections of bioactive nanoscale materials that harden under the
action of body fluids. Target materials are designed to mimic and
Medical and Nanotechnology Pharmaceutical Applications