Biomedical Engineering Reference
In-Depth Information
d
n
4
y
3
n
g
|
7
Figure 10.3
(a) One-pot synthesis of polyMPC-graft-CPT copolymers. (b) Aqueous
GPC trace of copolymer. (c) Light scattering intensity vs. concentration
of copolymer (inset is polymer diameter distribution). (Reproduced
from
al.
53
Chen
et
with
permission
from
the
American
Chemical
Society.)
delivery of the nanoparticles to the cells was effectively reduced because of the
stealth of the MPC units. Licciardi et al.
57
developed a successful route
involving ATRP of MPC followed by a tertiary amine methacrylate using a 9-
fluorenylmethyl chloroformate (Fmoc)-protected ATRP initiator. Folic acid
(FA)-functionalized biocompatible block copolymers could be obtained by the
deprotection of the Fmoc groups, which could avoid introduction of
additional units for conjugation in the final NDVs. FA-MPC-DPA (DPA 5
diisopropylaminoethyl methacrylate) copolymers have been evaluated as pH-
responsive micellar vehicles for the delivery of highly hydrophobic anticancer
drugs, namely tamoxifen and paclitaxel.
Besides active targeting, intelligent-responsible properties of the drug
vesicles are a very important factor to enhance drug release. Stimuli-sensitive
materials can be obtained by the addition of monomers, such as pH-sensitive
DPA. Salvage et al.
58
prepared nanoparticles using PMPC-b-PDPA diblock
copolymers. The novel nontoxic biocompatible micelles formed by MPC-DPA
diblock copolymers have appropriate size and good colloidal stability, as well
as exhibiting pH-modulated drug uptake and release. Lv et al.
59
synthesized a
series of amphiphilic random copolymers with MPC as the hydrophilic
segment, stearyl methacrylate (SMA) as the hydrophobic segment, and
glycidyl methacrylate (GMA) as the reactive segment. The polymeric micelles
were crosslinked with a difunctional reagent, cystamine. The crosslinked
micelles showed improved stability and de-crosslinking of disulfide bonds by
