1 research outputs found
Side-Chain Amino-Acid-Based pH-Responsive Self-Assembled Block Copolymers for Drug Delivery and Gene Transfer
Developing
safe and effective nanocarriers for multitype of delivery system is
advantageous for several kinds of successful biomedicinal therapy
with the same carrier. In the present study, we have designed amino
acid biomolecules derived hybrid block copolymers which can act as
a promising vehicle for both drug delivery and gene transfer. Two
representative natural chiral amino acid-containing (l-phenylalanine
and l-alanine) vinyl monomers were polymerized via reversible
addition–fragmentation chain transfer (RAFT) process in the
presence of monomethoxy polyÂ(ethylene glycol) based macro-chain transfer
agents (mPEG<sub><i>n</i></sub>-CTA) for the synthesis of
well-defined side-chain amino-acid-based amphiphilic block copolymers,
monomethoxy polyÂ(ethylene glycol)-<i>b</i>-polyÂ(Boc-amino
acid methacryloyloxyethyl ester) (mPEG<sub><i>n</i></sub>-<i>b</i>-PÂ(Boc-AA-EMA)). The self-assembled micellar aggregation
of these amphiphilic block copolymers were studied by fluorescence
spectroscopy, atomic force microscopy (AFM) and scanning electron
microscopy (SEM). Potential applications of these hybrid polymers
as drug carrier have been demonstrated <i>in vitro</i> by
encapsulation of nile red dye or doxorubicin drug into the core of
the micellar nanoaggregates. Deprotection of side-chain Boc- groups
in the amphiphilic block copolymers subsequently transformed them
into double hydrophilic pH-responsive cationic block copolymers having
primary amino groups in the side-chain terminal. The DNA binding ability
of these cationic block copolymers were further investigated by using
agarose gel retardation assay and AFM. The <i>in vitro</i> cytotoxicity assay demonstrated their biocompatible nature and these
polymers can serve as “smart” materials for promising
bioapplications