Biomedical Engineering Reference
In-Depth Information
and developing a sustainable environment [42]. Smalley [44]
classiied nanotechnology into two categories: “wet” nanotechnology
(including living biosystems) and “dry” nanotechnology. Research
on dry nanostructures is now seeking systematic approaches
to engineer man-made objects at the nanoscale and to integrate
nanoscale structures into large-scale structures, as nature does.
The relationship between biomaterials and nanotechnology
was discussed recently by Williams [54]. Three aspects were
considered:
(i) In many medical applications, the form of the biomaterial is
speciically designed such that it is presented to the human
body as a unit with nanoscale dimensions. It is important
that such material has distinctly different properties from the
bulk material as a consequence of its occurrence as discrete
entities for it to be considered a nanomaterial.
(ii) Biocompatibility phenomena are controlled by nanoscale
topographical features. It is known that interactions between
cells and biomaterial surfaces are mediated by molecules
and structures on cell membranes and within the cytoplasm.
Therefore, the behavior of such cells at the interface
with a biomaterial may be profoundly inluenced by the
nanotopography.
(iii) Nanotechnologies have positively inluenced the quality of life
through advances in medicine and biotechnology; however, it
is also possible that they may be associated with health and
environmental risks [15, 32, 33]. The rapid progress in the
industry causes, for example, huge quantities of nanoparticles
in the air produced by combustion. Small size alone is not the
critical factor in the toxicity of nanoparticles, but the overall
number and thus the total surface area (essentially the dose)
are also important. Therefore, we have to note the increasing
risk due to the development of new materials and wider
applications based on nanotechnology.
A large number of potential applications of nanotechnologies
are now opening up. Some reports give an overview of current and
potential future developments in nanoscience and nanotechnologies
and their health, safety, environmental, social, and ethical
implications. Much of nanoscience and many nanotechnologies
are concerned with producing new or enhanced materials. Some
