Biomedical Engineering Reference
In-Depth Information
d
n
4
y
3
n
g
|
4
Figure 6.2
PTMC-b-PGA polymersomes simultaneously loaded with DOX and
Fe
2
O
3
nanoparticles. (Reproduced from Sanson et al.
18
with permission
from the American Chemical Society.)
of a 9L glioma-bearing rat.
16
Polymersomes also offer good carriers for both
hydrophobic and hydrophilic substances simultaneously. Discher et al.
reported that intravenous injection of DOX?HCl- and PTX-loaded PEG-
PCL polymersomes into nude mice bearing human breast carcinoma brought
about growth arrest and shrinkage of rapidly growing tumors.
17
Lecommandoux et al. developed theranostic PTMC-b-PGA polymersomes
simultaneously loaded with DOX and Fe
2
O
3
nanoparticles, which displayed
enhanced contrast properties and triggered DOX release by radiofrequency
magnetic hyperthermia (Figure 6.2).
18
Drug release profiles from polymersomes can be elegantly controlled by
manipulating polymersome degradability, membrane permeability, and
stimuli-responsive properties.
19,20
It should further be noted that targeting
polymersomes that selectively deliver payloads to the sites of action can be
prepared by decorating polymersomes with a specific ligand such as an
antibody, peptide, or folate (Figure 6.3).
21
In this chapter we will highlight the
recent development of functional polymersomes, including stimuli-sensitive
polymersomes,
chimaeric
polymersomes,
biomimetic
polymersomes,
and
tumor-targeting polymersomes.
6.2 Stimuli-Responsive Polymersomes
Stimuli-sensitive polymersomes have emerged as novel programmable delivery
systems in which the release of the encapsulated content is modulated by a
stimulus.
20,22
In particular, pH and reduction are the two most appealing
stimuli as they exist naturally in certain pathological sites and/or intracellular
compartments.
23,24
For example, taking advantage of acidic endo/lysosomal
compartments, Forster et al. developed pH-sensitive polymersomes from PEO-
poly(2-vinylpyridine)
(PEO-P2VP),
25
Armes
et
al.
reported
pH-sensitive
