Biomedical Engineering Reference
In-Depth Information
Owing to its toxicity, the use of cadmium is restricted in living cells. This
is why the process of nanofabrication, in particular the preparation of gold
nanodots or quantum dots, is well known. In 2007, the National Medal of
Science, the United States' highest honor in the field, was awarded to the
Egyptian-American chemist Professor Mostafa El-Sayed, director of the
Laser Dynamics Laboratory of the Georgia Institute of Technology, for his
many outstanding contributions, among which using gold nanorods in can-
cer tumor treatment was the most recent. Gold nanoparticles are very good
at scattering and absorbing light. For example, nanoparticles that are 36 nm
wide absorb light over 10,000 times better than conventional organic dyes,
making them potential candidates for optical imaging applications of small
tumors. In the study, researchers found that gold nanoparticles have 600%
greater affinity for specific overexpressed surface receptors in cancer cells
than in noncancerous cells.
As nanotechnology tended to progress in a most responsible manner
from the moment of its foundation, when the US National Nanotechnology
Initiative (NNI) was established in 2000, it seems to have the most number
of regulatory mechanisms for greener development than any other known
technology, and social scientists have been involved from the very beginning.
Green nanotechnology is developed to be environmentally friendly. Dr. Jim
Hutchinson's research group at the University of Oregon works at the cleaner
and greener production of gold nanoparticles, a process that also reduces the
cost of synthesizing these materials from 300,000 to 500 dollars per gram. 19
Actually, cost is one of the determining factors for manufacturing, next to
safety and effectiveness.
Recent studies have enabled the synthesis of gold nanoparticles by means
of certain bacterial strains; for example, Stenotrophomonas maltophilia was
incubated for 8 h in a gold salt-containing solution, resulting in the synthesis
of gold nanoparticles that were about 40 nm in size. 20 The opportunity of
this way of synthesis is that it produces gold nanoparticles that are free of
solvent and have hydrophilic properties, and may attain particles of various
sizes in industrial quantities. This is a new approach to green technology
development.
A recent report by J. Davies, from the Woodrow Wilson International
Center of Scholars, strongly criticized the current approach in cosmetics
regulation as wholly inadequate in dealing with the risks posed by nano-
technologies: “Although the Food, Drug and Cosmetic Act (FDCA) has a lot
of language devoted to cosmetics, it is not too much of an exaggeration to say
that cosmetics in the USA are essentially unregulated.” 21
David Rejeski, director of the Project on Emerging Nanotechnologies,
Woodrow Wilson International Center of Scholars, gives recommenda-
tions: “for building confidence in nanotechnologies it is necessary to achieve
greater transparency and disclosure; compulsory requirement is also pre-
market testing, as well involvement of third party for additional testing and
further research.” 22 Although some cosmetic manufacturers may differ with
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