Biomedical Engineering Reference
In-Depth Information
about US$254 billion in 2009, with nanomedical products accounting for a margin
of US$72.8 billion in 2011 [
3
].
The US government has granted more than US$20 billion to the US National
Nanotechnology Initiative for nanotechnology research and development activities,
facilities, and workforce training since 2000 [
4
]. In 2011, the Canadian Institutes of
Health Research (CIHR) and the Canadian Space Agency (CSA) have granted US
$16 million in funding to seven new research projects on regenerative medicine and
nanomedicine [
5
]. The European Framework Program [
6
] will invest about 600 mil-
lion euros per year for nanotechnology research until 2013, with a supplementary,
comparable sum provided by individual countries [
7
]. The economic landscape is
thus being dramatically altered by nanotechnology. For instance, in 2004, world-
wide corporations spent US$3.8 billion on research and development [
8
]. More
importantly, there is a shift from the discovery stage to applications on nanotech-
nology, as demonstrated by the ratio increased corporate patent applications to
scientific publications from 0.23 in 1999 to 1.2 in 2008 [
2
]. Additionally, analysts
estimate that by 2014, nanotechnology will be responsible for 15 % of all
manufactured merchandise, valuing approximately US$2.6 trillion and will create
10 million jobs globally [
1
].
Physicochemical properties of nanoparticles such as their small size, large
surface area, and kinetics of adsorption make them particularly interesting as
tools for molecular diagnostics, in vivo imaging, and improved treatment of
disease. Metal oxides have been introduced in the early 1960s as ferromagnetic
separation moieties and have brought about the use of nanoparticles for magnetic
resonance imaging (MRI) in the late 1970s. More recently, application of
nanoparticles to medicine has expanded to cellular therapy [
9
], tissue repair [
10
],
drug delivery [
11
], hyperthermia [
12
], (MRI) [
13
], magnetic resonance spectros-
copy [
14
], magnetic separation [
15
], and as sensors for metabolites and other
biomolecule [
16
]. Moreover, the unique magnetic properties and small size of
magnetic nanoparticles (MNPs) make them appealing for biomolecule labeling in
bioassays, as well as MRI contrast agents [
17
]. Superparamagnetic iron oxide
(SPIO) can also be used as magnetic gradients for cell sorting in bioreactors [
18
],
as well as absorbing material in radio-frequency hyperthermia. Moreover, the
exceptional physical, mechanical, and electronic properties of carbon nanotubes
(CNTs) allow them to be used as biosensors, probes, actuators, nanoelectronic
devices, drug-delivery systems, and tissue-repair scaffolds within biomedical
applications [
19
-
21
]. Recent research has focused on conjugating nanocarriers to
specific ligands such as peptides, antibodies, and small molecules and subsequently
directing them to sites of interest [
22
]. These techniques can prove to be appealing
alternatives for current cancer and cardiovascular applications.
Thus, a vast array of nanotechnologies can be applied to medical devices,
materials, and processes that will affect the prevention, early diagnosis, and treat-
ment of diseases. However, the risk-benefit balance for these materials, with regard
to their toxicological profile and any potential adverse pathogenic reactions from
exposure, will ultimately define their clinical outcome.
