AIE-Based Fluorescent Triblock Copolymer Micelles for Simultaneous Drug Delivery and Intracellular Imaging
byKulkarni, B., Qutub, S., Ladelta, V., Khashab, N. M., Hadjichristidis, N.
Year:2021DOI:10.1021/acs.biomac.1c01165
Bibliography
Kulkarni, B.; Qutub, S.; Ladelta, V.; Khashab, N. M.; Hadjichristidis, N., AIE-Based Fluorescent Triblock Copolymer Micelles for Simultaneous Drug Delivery and Intracellular Imaging. Biomacromolecules 2021, 22, 5243-5255
Abstract
Fluorescent drug delivery systems have received increasing attention in
cancer therapy because they combine drug delivery and bioimaging into a
single platform. For example, polymers with aggregation-induced emission
(AIE) fluorophores, such as tetraphenylethylene (TPE), have emerged as
an elegant choice for drug delivery/bioimaging applications. In this
work, we report one-pot sequential organocatalytic ring-opening
polymerization of ε-caprolactone (CL) and ethylene oxide (EO) using
TPE-(OH)2 as a difunctional initiator, in the presence of a t-BuP2/TEB
Lewis pair (catalyst), in THF at room temperature. Two well-defined
triblock copolymers with inverse block sequences, TPE-(PCL-b-PEO)2 and TPE-(PEO-b-PCL)2,
were synthesized by altering the sequential addition of CL and EO. The
physicochemical properties, including hydrodynamic diameter, morphology,
and AIE properties of the synthesized amphiphilic triblock copolymers
were investigated in aqueous media. The block copolymer micelles were
loaded with anticancer drugs doxorubicin and curcumin to serve as drug
delivery vehicles. In vitro studies revealed the accelerated drug
release at lower pH (5.5), which mimics the tumor microenvironment,
different from the physiological pH (7.4). In vitro cytotoxicity studies
demonstrated that the neat block copolymer micelles are biocompatible,
while drug-loaded micelles exhibited a significant cytotoxic effect in
cancer cells. Cellular uptake, examined by confocal laser scanning
microscopy, showed that the block copolymer micelles were rapidly
internalized by the cells with simultaneous emission of TPE fluorophore.
These results suggest that these triblock copolymers can be utilized
for intracellular bioimaging.