1 research outputs found
pH-Triggered and Enhanced Simultaneous Photodynamic and Photothermal Therapy Guided by Photoacoustic and Photothermal Imaging
Developing
smart photosensitizers sensitively responding to tumor-specific
signals for reduced side effects and enhanced anticancer efficacy
is a major challenge for tumor phototherapy. Herein, a pH-sensitive
photosensitizer has been synthesized through introducing a pH-sensitive
receptor (dimethylaminophenyl unit) onto the aza-BODIPY core (abbreviated
as NAB). Through enveloping hydrophobic NAB with amphiphilic DSPE-mPEG<sub>2000</sub>, NAB nanoparticles (NPs, diameter ∼ 30 nm) with
strong near-infrared absorption (∼792 nm) are obtained. NAB
NPs can be activated in weak acidic environment to give high rate
of reactive oxygen species (ROS) generation and enhanced photothermal
effect. NAB NPs can selectively accumulate in the lysosomes of tumor
cells and subsequently activate under the acidic microenvironment
of lysosome (pH 5.0) to produce ROS for photodynamic therapy, due
to switch-off of the photoinduced electron transfer (PET) pathway.
In vivo, pH-enhanced photoacoustic imaging (PAI) and photothermal
imaging (PTI) confirm that NAB NPs can selectively aggregate in the
tumor, and the tumor growth can be effectively inhibited under xenon
lamp irradiation through synergistic phototherapy (photodynamic and
photothermal therapy, PDT/PTT). Furthermore, based on PAI signal and
terminal elimination half-life (<i>T</i><sub>1/2</sub>)
obtained by pharmacokinetic experiment, it is concluded that the NAB
NPs can be rapidly metabolized. The pH-sensitive NAB NPs offer a new
possibility toward PAI and PTI guided synergistic phototherapy