Pan European Networks - Horizon 2020 - page 178

Many nanoproducts involve liposomes, which
have an interest in concentrating in cancer
cells. Injected into the bloodstream, they cannot
pass through a normal vascular endothelium.
However, they pass through the endothelium of
tumour vessels – the cells are less tightly joined
– and into the malignant cells. These first-
generation nanodrugs are subject to the
phenomenon of opsonisation that leads to their
rapid uptake by the liver and their degradation.
The hepatic uptake is an asset when it comes
to treating liver cancer. However, it decreases
the amount of drugs that affect other target
organs since the plasma half-life is reduced.
Next generation
To avoid opsonisation, the second generation
of nanocarriers that have been developed are
covered with polyethylene glycol. These
nanoproducts, called ‘stealth’, escape uptake
by liver macrophages. They stay longer in the
bloodstream and reach more of their extra-
hepatic targets.
Third-generation nanocarriers are still at the
experimental phase. They involve, in addition to
stealth properties, a targeting molecule which
can be the ligand of a receptor or an antibody
directed against a protein overexpressed in the
target tissue antibodies. These vectors are used
to address the drug directly to the target, which
gives hope for improved efficiency, reduced
toxicity and lower doses.
T
ackling cardiovascular diseases (CVD) is a public health priority.
Earlier diagnoses and ways to improve therapies are urgently
required, and nanomedicine has the potential to revolutionise
current clinical practice. Indeed, CVDs are the main cause of death in
Europe. Diseases of the heart and circulatory system account for over
four million deaths each year. Nearly half (47%) of all deaths are from
CVD, and the main forms of it are coronary heart disease and stroke.
Efforts to reduce mortality from CVDs have been successful; however,
the cost to the EU economies of cardiovascular diseases is not
decreasing. Overall, CVD is estimated to cost the Union’s economy nearly
€200bn a year.
CVDs (heart attack, heart failure, angina) are diseases of the heart
(cardiac muscle) or blood vessels (vasculature). The term ‘heart disease’
(or coronary heart disease (CHD)) is used for conditions caused by
narrowing of the heart blood vessels (coronary arteries) by atheroma.
Cerebrovascular diseases (stroke and transient ischaemic attack) are
diseases of the arteries in the brain. Consequently, one of the most
important actions to improve human survival and quality of life is the
treatment of CVD.
Pharmaceutical treatments already play a major role in the prevention
of atherosclerosis and its consequences. At the same time, the use of
percutaneous coronary interventions, which improve survival rates after
a CHD event, has become more common. Additionally, innovative
strategies based on efficacious drugs (nanotherapies), early risk factor
screening, and better follow-up by imaging could contribute to the decline
in cardiac morbidity and mortality in the future.
Nanomedicine promise
Indeed, nanomedicine is the medical application of nanotechnology, a
term used for materials and devices that operate at the nanoscale. In
the metric system, nanosystems are typically measured in nanometres
and they encompass systems whose size is above molecular dimensions
and below macroscopic ones (generally between 1nm and 100nm in
scale). Nanosystems are thus in the same scale as numerous biologic
molecules. With their size, nanosystems have high surface area to volume
ratios. Additionally, an internal volume is sometimes provided by
nanosystems for drugs or imaging agents. Nanosystems encapsulate
and enable controlled release, helping the delivery rate of drugs. These
are important features of nanosystems that make them particularly well
suited as drug delivery carriers or imaging agents in medicine.
Nanomedicine also involves the development of systems for imaging
and/or treatment and brings hopes for personalised medicine. Currently,
nanotechnology is a fast-moving field gaining support from scientists in
the academic, industrial and regulatory/federal sectors.
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H O R I Z O N 2 0 2 0 P R O J E C T S : P O R TA L
178
H E A L T H : D I S E A S E R E S E A R C H
A new way
Didier Letourneur,
head of cardiovascular bioengineering and director of the
Laboratory for Vascular Translational Science at Inserm, discusses the role of
nanomedicine in tackling CVD and the NanoAthero project’s breakthroughs
Fig. 1 General scheme
of nanosystems for
imaging or therapy
Didier Letourneur
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