Biomedical Engineering Reference
In-Depth Information
neurotensin peptide for the delivery of liposomal doxorubicin [196]. h e
branched peptide had higher targeting ei ciency to cancer cells than its
linear form on account of its ability to bind multivalently to receptor clus-
ters. It is important to keep in mind that in general, the downside of an
increased targeting ability is faster uptake by the MPS. Another interest-
ing concept is the development of poly(amino acid) peptide sequences,
like oligo-arginine for the ei cient cell-penetration of liposomes [197] and
the subsequent delivery of macromolecular drug [198] and genetic cargo
[199]. Such sequences have also been successfully used for the targeting of
intracellular organelles [200, 201].
In the past decade, the RGD peptide and its analogs has been widely
used in the targeting of cell-surface integrins [202]. h e potential of RGD
peptides in the targeting of integrins of tumour vasculature with liposomes
containing a vascular disrupting agent ZD6126 [203] as well as siRNA has
been well demonstrated [204]. Another popular cell-penetrating peptide
is the transactivating transduction peptide (TATp). Recently, it was shown
that TATp anchored to cholesterol enhanced liposomal delivery to the
brain [205, 206].
3.3.2.5
Targeting with Other Ligands
Apart from the targeting moieties discussed above, various other ligands
including small molecules have also been used for the liposomal deliv-
ery of biological actives [207]. Hydroxy-apatite targeting liposomes were
used to deliver hydrophobic drugs specii cally to bone tissue [208]. h e
potential of hyaluronic acid-modii ed liposomes as vehicles for gene
delivery into the liver endothelial cells [209] as well as the delivery of
anti-cancer drugs like gemcitabine to pancreatic cancer cells have been
demonstrated [210]. Similarly, interleukin 13-liposomes containing
doxorubicin were shown to be a viable option for the treatment of glio-
blastoma multiforme [211]. Liposomal doxorubicin targeted with oval-
bumin was also evaluated as a potential immune suppressant [212]. h e
potential of the wheat germ agglutinin in the pulmonary delivery of lipo-
somal calcitonin, a model peptide drug, to alveolar epithelial cells was
demonstrated [213].
Recently, triphenylphosphonium, a lipophilic cation, was used to
deliver liposomal paclitaxel [214] and sclareol [215] specii cally to mito-
chondria. Similarly, octadecyl-rhodamine B was used for the intracellular
targeting of lysosomes as a model for the treatment of lysosome-stor-
age diseases [216]. Anginex-coated l uorescently labeled paramagnetic
