Biomedical Engineering Reference
In-Depth Information
coronary artery stents (Mahapatro et al. , 2006). Similarly thrombin coated
magnetic microbeads positioned (using a magnetic fi eld) in fi brin gels to
produce scaffolds show adhesion and proliferation of human endothelial
cells (Alsberg et al. , 2006).
Nanofi bre technology has diversifi ed considerably since its inception.
Under exploration is 'magnetic force-based tissue engineering' which
employs the labelling of sheets of endothelial cells, smooth muscle cells and
fi broblasts using magnetite cationic liposomes. Using a magnetic fi eld these
sheets are rolled to form a tube (Ito et al. , 2005a). Also being investigated
are porous micropatterned poly-caprolactone scaffolds (in an attempt
to maintain adequate nutrient diffusion) and 'pressure assisted cell
spinning' (a possible rival process to electrospinning) (Sarkar et al. , 2006;
Arumuganathar et al. , 2007).
9.4
Future trends
9.4.1 Challenges
Nanomedicine has displayed great potential in cardiovascular disease.
However, as with any novel agent it is important to be aware of the risks
involved.
Human endothelial cells exposed to alumina nanoparticles have increased
adhesion of activated monocytes and expression of VCAM-1, ICAM-1 and
ELAM-1. This proinfl ammatory response of the endothelium together with
increased expression of such adhesion molecules may promote atheroscle-
rosis (Oesterling et al. , 2008). In some cases nanoparticles may have a
prothrombotic effect, such as carbon nanotubes which stimulate platelet
aggregation with an accelerated rate of vascular thrombosis in rat carotid
arteries (Radomski et al. , 2005). Increased platelet aggregation has also
been displayed with the use of carbon black and water-soluble fullerenes
(Niwa and Iwai, 2007). Water-soluble fullerenes have also exhibited the
ability to inhibit endothelial cell growth (Yamawaki and Iwai, 2006). Sys-
temically, nanoparticles may be nephrotoxic. The respiratory system may
also be at risk from systemic administration especially if nanoparticles are
delivered as aerosols (Card et al. , 2008).
￿ ￿ ￿ ￿ ￿
9.4.2 Nanomedicine and cardiovascular disease
in the future
In conclusion, the future of nanoparticles in the treatment of cardiovascular
disease lies in their ability to fulfi l complementary roles by combining both
diagnostic (i.e. imaging) and therapeutic functions. The progress of multi-
functional nanoparticle research has been dominated by the treatment of
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