| The mainstreams of conventional cancer
treatment remain chemotherapy and
radiotherapy. These traditional therapeutic
approaches are plagued by poor tissue
targeting, inducing destruction of healthy
tissue, which results in toxic side-effects, as
well as suboptimal dosing of the targeted
area.
In addition to traditional small
molecule chemotherapeutic agents, a
plethora of biological agents have the
potential to be used in the treatment of
cancer. Many substances have demonstrated
useful efficacies in vitro, but have failed in
their ability to alleviate the disease in vivo
due to a wide range of issues including poor
dosing of target area, low bioavailability and
inability to internalise to the tumour cells.
Thus, once administered into the circulatory
system, biologics such as proteins and
peptides are subjected to various immune
mechanisms, such as opsonisation and
receptor endocytosis. Those mechanisms,
in addition to renal filtration induce rapid
degradation of most therapeutic proteins,
limiting their usefulness.
In recent years, drug delivery research
has examined the formulation of a full
spectrum of nanoparticles that can suit
various drugs types, with different
parameters, such as size, entrapment
efficiency or release profile, studied in
depth. Additionally, delivery of poor
water soluble chemotherapy drugs,
such as Docetaxel or Paclitaxel, have been
improved through their encapsulation
inside nanoparticle carriers, demonstrating
increased in vivo efficiency compared with
naked administration.
Furthermore, in an
attempt to produce specific targeted delivery
carriers, a range of molecules have been
grafted on the surface of the nanoparticles
to induce interaction with cells and active
internalisation of the particles inside the
tumours. The main classes of nanoparticle
and antibody mediated targeting strategies
are briefly discussed in this article.
CLASSES OF NANOPARTICLE Liposomes
Lipososmes are among the first and
most intensely studied and evaluated
nanoparticles. The development of liposomal vesicular carriers has been
pursued based on the concept of
mimicking natural lipid bilayers and
micelle formation. |
