Activation of vasa vasorum at specific sites in the adventitia initiates their proliferation or
“angiogenesis” concomitant with development of atherosclerotic plaques. Haemorrhagic, leaky blood
vessels from unstable plaques proliferate abnormally, are of relatively large calibre but are immature
neovessels poorly invested with smooth muscle cells and possess structural weaknesses which may
contribute to instability of the plaque by facilitation of inflammatory cell infiltration and haemorrhagic
complications. Weak neovascular beds in plaque intima as well as activated adventitial blood vessels
are potential targets for molecular imaging and targeted drug therapy, however, the majority of potential
imaging and therapeutic agents have been unsuccessful because of their limited capacity to reach and
remain stably within the target tissue or cells in vivo. Nanoparticle technology together with magnetic
resonance imaging has allowed the possibility of imaging of neovessels in coronary or carotid plaques,
and infusion of nanoparticle suspensions using infusion catheters or implant based drug delivery
represents a novel and potentially much more efficient option for treatment. This review will investigate
the possibility of future design of nanoparticles which home to the vasa vasorum and which can release
siRNA directed against primary key external mitogens and intracellular signalling molecules in
endothelial cells responsible for their activation with a view to inhibition of angiogenesis.
Keywords: Atherosclerosis; angiogenesis; plaque; cardiovascular disease; stroke; nanoparticle, targeting;
imaging, microvessel; inflammation.
