1 research outputs found
Small Molecule-Initiated Light-Activated Semiconducting Polymer Dots: An Integrated Nanoplatform for Targeted Photodynamic Therapy and Imaging of Cancer Cells
Photodynamic therapy (PDT) is a noninvasive
and light-activated
method for cancer treatment. Two of the vital parameters that govern
the efficiency of PDT are the light irradiation to the photosensitizer
and visual detection of the selective accumulation of the photosensitizer
in malignant cells. Herein, we prepared an integrated nanoplatform
for targeted PDT and imaging of cancer cells using folic acid and
horseradish peroxidase (HRP)-bifunctionalized semiconducting polymer
dots (FH-Pdots). In the FH-Pdots, meta-tetraÂ(hydroxyphenyl)-chlorin
(m-THPC) was used as photosensitizer to produce cytotoxic reactive
oxygen species (ROS); fluorescent semiconducting polymer polyÂ[2-methoxy-5-((2-ethylhexyl)Âoxy)-<i>p</i>-phenylenevinylene] was used as light antenna and hydrophobic
matrix for incorporating m-THPC, and amphiphilic Janus dendrimer was
used as a surface functionalization agent to conjugate HRP and aminated
folic acid onto the surface of FH-Pdots. Results indicated that the
doped m-THPC can be simultaneously excited by the on-site luminol–H<sub>2</sub>O<sub>2</sub>–HRP chemiluminescence system through
two paths. One is directly through chemiluminescence resonance energy
transfer (CRET), and the other is through CRET and subsequent fluorescence
resonance energy transfer. In vitro PDT and specificity studies of
FH-Pdots using a standard transcriptional and translational assay
against MCF-7 breast cancer cells, C6 glioma cells, and NIH 3T3 fibroblast
cells demonstrated that cell viability decreased with increasing concentration
of FH-Pdots. At the same concentration of FH-Pdots, the decrease in
cell viability was positively relevant with increasing folate receptor
expression. Results from in vitro fluorescence imaging exhibited that
more FH-Pdots were internalized by cancerous MCF-7 and C6 cells than
by noncancerous NIH 3T3 cells. All the results demonstrate that the
designed semiconducting FH-Pdots can be used as an integrated nanoplatform
for targeted PDT and on-site imaging of cancer cells