Biomedical Engineering Reference
In-Depth Information
Free drugs
Receptor
Through
enhanced
permeation
effect
Nanocarrier
Ligand
Cancer cell
Increase in intracellular
drug concentration
Blood capillary
Nanoparticles targeting Cancer cells
Figure 14.7
Nanoparticles target cancer cells through ligand receptor binding.
mechanisms for localization of tumour site [119]. Active tumour targeting
involved the use of molecules which specii cally interact with the physi-
ological target whereas the passive targeting involves the use of natural
properties and processes in the tissues for localization of the delivery agent
at a desired target site. Passive tumour targeting is mainly by EPR ef ect.
Particles within the range of 100-200 nm have been shown to accumulate
in tumour by EPR ef ect.
Wa n g
et al
studied the biodistribution of targeted nanoparticles com-
posed of heparin-folate-paclitaxel conjugates loaded with paclitaxel and
compared it with the non-targeted nanoparticles of heparin-paclitaxel
loaded with paclitaxel, as a result, this targeted system loaded with the
drug reduces the tumour volume over nanoparticle and paclitaxel con-
trol in the KB-3-1 human nasopharyngeal carcinoma-xenograt bearing
mouse model [120]. Another most common targeting ligand such as trans-
ferrin (Tf ) has been conjugated to a variety of targeted delivery systems for
targeting over expressive Tf receptors which are common in many can-
cerous cells. h ey basically improve the drug delivery [121]. Liposomes
possessing an anti-HER2 monoclonal antibody (Mab) composed of phos-
phatidylcholine and polyethylene glycol (PEG) modii ed distearoyl phos-
phatidylethanolamine with an average particle diameter of 100 nm has
resulted in improve antitumor ei cacy of doxorubicin over the various
control formulations [122]. Kirpotin
et al.
further evaluated the biodistri-
bution and uptake of these targeted liposomes containing the anti-HER2
Mab and compared it with that of non -targeted liposomes [123].
In 1975,
