C hapTer 11 nanomaterials and nanotechnologies
472
be compatible with existing bone fabrics and surrounding body
materials.
In many situations, implants—for example, strengthening plates or
artificial bones—need to be used. Common implant materials are
stainless steels or titanium, which do not react to human tissues
(biological fluids are quite corrosive). The current state of the
art is remarkably high, but issues with implants remain. In many
situations, the mechanical wear on these implants is high and
periodic expensive replacement can be needed. These materials are
also inherently not porous. There should be some porosity so
that the surrounding body tissue material joins to the implants.
Ideally, the materials used should have some kind of bioactive
characteristics.
As discussed previously, nanocomposites can have excellent strength
and hardness characteristics that could help address the problem
of mechanical wear and reduce the need for periodic replacement. Many metallic nanocomposites could address this problem.
Nanoceramics, such as the nanocrystalline zirconium oxide, are
also particularly interesting since they can be made extremely hard,
wear-resistant, and more porous. They are also biocompatible and
do not react to corrosive biological fluids.
The coupling of nanoelectronics systems with implants opens new
treatment doors. Opportunities are just starting to be explored, but
amazing possibilities, such as a responsive artificial retina, are certainly imaginable. Larger prosthetic devices can also benefit from
the sensing and control systems possible via small nanoelectronic
devices.
11.3 healTh ConCerns
Our society is already keenly attuned to health and environmental issues, and public health researchers have long struggled with
understanding and quantifying the risks associated with known
health hazards in relation to the many fine particulates that already
exhibit nanoscale dimensions and that are the byproducts of many
natural forces or human processes (e.g., volcanic ash or diesel
soot emissions). In the eyes of both the public and the scientific
research community, it does not take much of a leap to appreciate that engineered nanoparticles that can possibly be ingested
or inhaled or that might otherwise find their way into human
bloodstreams in some manner might indeed be a potential cause
for health concerns. There are already contentious debates arising
472
be compatible with existing bone fabrics and surrounding body
materials.
In many situations, implants—for example, strengthening plates or
artificial bones—need to be used. Common implant materials are
stainless steels or titanium, which do not react to human tissues
(biological fluids are quite corrosive). The current state of the
art is remarkably high, but issues with implants remain. In many
situations, the mechanical wear on these implants is high and
periodic expensive replacement can be needed. These materials are
also inherently not porous. There should be some porosity so
that the surrounding body tissue material joins to the implants.
Ideally, the materials used should have some kind of bioactive
characteristics.
As discussed previously, nanocomposites can have excellent strength
and hardness characteristics that could help address the problem
of mechanical wear and reduce the need for periodic replacement. Many metallic nanocomposites could address this problem.
Nanoceramics, such as the nanocrystalline zirconium oxide, are
also particularly interesting since they can be made extremely hard,
wear-resistant, and more porous. They are also biocompatible and
do not react to corrosive biological fluids.
The coupling of nanoelectronics systems with implants opens new
treatment doors. Opportunities are just starting to be explored, but
amazing possibilities, such as a responsive artificial retina, are certainly imaginable. Larger prosthetic devices can also benefit from
the sensing and control systems possible via small nanoelectronic
devices.
11.3 healTh ConCerns
Our society is already keenly attuned to health and environmental issues, and public health researchers have long struggled with
understanding and quantifying the risks associated with known
health hazards in relation to the many fine particulates that already
exhibit nanoscale dimensions and that are the byproducts of many
natural forces or human processes (e.g., volcanic ash or diesel
soot emissions). In the eyes of both the public and the scientific
research community, it does not take much of a leap to appreciate that engineered nanoparticles that can possibly be ingested
or inhaled or that might otherwise find their way into human
bloodstreams in some manner might indeed be a potential cause
for health concerns. There are already contentious debates arising