Biomedical Engineering Reference
In-Depth Information
Fig. 9
Magnetic resonance images of mice at various time points after the tail vein injection of
polydisulfide DNCs or PAMAM(G3)-[Gd-C-DOTA]. Adapted from Huang et al., with permis-
sion from American Chemical Society. Copyright 2012
superparamagnetic iron oxide (IONPs) (FA-PEG-G3.5-PTX-Cy5.5@IONPs) and
studied the in vitro targeting ability towards MCF-7 (breast cancer) cells (Fig.
10
).
Peptide conjugated PEGylated-polypropylenimine (PPI) dendrimer with numer-
ous hydrophobic pockets can encapsulate photosensitizers such as phthalocyanines
(Pc) for fluorescence image-guided drug delivery and noninvasive treatment of
deep tumors by photodynamic therapy (PDT) (Fig.
11
). Such Pc based theranos-
tic modalities allow fluorescence based imaging of malignant tissue when accu-
mulated and thereafter near infrared (NIR) light can be precisely applied on the
detected cancer tissue for PDT leaving the healthy organs untouched (Taratula
et al. 2013).
Efforts are being laid on development of asymmetric dendritic structures with
high structural complexity to provide multiple functionalities for delivery of thera-
nostic agents. Ornelas et al. (2011) synthesized a Janus-like multifunctional den-
drimer comprising of 9 azide termini, 9 amine termini and 54 terminal acid groups
as next generation of materials for cancer theranostics. Dendrimers can also be
linked to other nanomaterials such as carbon nanotubes (CNTs) to improve the
drug loading capacity and achieve targeted delivery to cancer cells. In one such
attempt, Wen et al. (2013) designed PAMAM G5/FA/FI (fluorescein isothiocy-
anate)—multiwalled carbon nanotubes (MWCNTs) for targeted and pH respon-
sive delivery of DOX to KB cells over expressing folic acid receptors (FAR). The
complexes showed high drug payload and encapsulating efficiency of 97.8 and
