3 research outputs found
Amplified Chemiluminescence Signal for Sensing Fluoride Ions
Bringing
together the concepts of self-immolative linkers and chemiluminogen
dioxetane modules, a chemiluminescence-based sensor for fluoride with
signal amplification is presented. Signal amplification is obtained
by triggering two chemiluminescence events for each reacting fluoride
ion that in turn releases two fluoride ions for each ion. As expected,
the chemiluminescence signal starts to rise following an induction
period. In addition to the analytical potential, this chemical system
is also of interest as a demonstration of positive feedback loop character
Photocaged DNA-Binding Photosensitizer Enables Photocontrol of Nuclear Entry for Dual-Targeted Photodynamic Therapy
Photodynamic therapy (PDT) is a clinically approved cancer
treatment
that requires a photosensitizer (PS), light, and molecular oxygena
combination which produces reactive oxygen species (ROS) that can
induce cancer cell death. To enhance the efficacy of PDT, dual-targeted
strategies have been explored where two photosensitizers are administered
and localize to different subcellular organelles. To date, a single
small-molecule conjugate for dual-targeted PDT with light-controlled
nuclear localization has not been achieved. We designed a probe composed
of a DNA-binding PS (Br-DAPI) and a photosensitizing photocage (WinterGreen).
Illumination with 480 nm light removes WinterGreen from the conjugate
and produces singlet oxygen mainly in the cytosol, while Br-DAPI localizes
to nuclei, binds DNA, and produces ROS using one- or two-photon illumination.
We observe synergistic photocytotoxicity in MCF7 breast cancer cells,
and a reduction in size of three-dimensional (3D) tumor spheroids,
demonstrating that nuclear/cytosolic photosensitization using a single
agent can enhance PDT efficacy
Photocaged DNA-Binding Photosensitizer Enables Photocontrol of Nuclear Entry for Dual-Targeted Photodynamic Therapy
Photodynamic therapy (PDT) is a clinically approved cancer
treatment
that requires a photosensitizer (PS), light, and molecular oxygena
combination which produces reactive oxygen species (ROS) that can
induce cancer cell death. To enhance the efficacy of PDT, dual-targeted
strategies have been explored where two photosensitizers are administered
and localize to different subcellular organelles. To date, a single
small-molecule conjugate for dual-targeted PDT with light-controlled
nuclear localization has not been achieved. We designed a probe composed
of a DNA-binding PS (Br-DAPI) and a photosensitizing photocage (WinterGreen).
Illumination with 480 nm light removes WinterGreen from the conjugate
and produces singlet oxygen mainly in the cytosol, while Br-DAPI localizes
to nuclei, binds DNA, and produces ROS using one- or two-photon illumination.
We observe synergistic photocytotoxicity in MCF7 breast cancer cells,
and a reduction in size of three-dimensional (3D) tumor spheroids,
demonstrating that nuclear/cytosolic photosensitization using a single
agent can enhance PDT efficacy