2 research outputs found
A Ratiometric Fluorescence Universal Platform Based on N, Cu Codoped Carbon Dots to Detect Metabolites Participating in H<sub>2</sub>O<sub>2</sub>‑Generation Reactions
In this work, a new
kind of N, Cu codoped carbon dots (N/Cu-CDs)
was prepared via a facile one-pot hydrothermal method by using citric
acid monohydrate, copper acetate monohydrate and diethylenetriamine.
The prepared N/Cu-CDs with a high quantum yield (50.1%) showed excitation-independent
emission at 460 nm. The structure and fluorescence properties of N/Cu-CDs
were characterized by high-resolution transmission electron microscopy,
fluorescence spectrofluorometer, FT-IR spectrometer, UV–visible
spectrophotometer and X-ray photoelectron spectroscopy. N/Cu-CDs were
applied to establishing a ratiometric fluorescence probe toward H<sub>2</sub>O<sub>2</sub> based on the inner filter effect (IFE) between
N/Cu-CDs and DAP (2,3-diaminophenazine, the oxidative product of o-phenylenediamine
(OPD)), and provided a ratiometric fluorescence universal platform
for detection of the metabolites participating in H<sub>2</sub>O<sub>2</sub>-generation reactions (cholesterol and xanthine). The proposed
method was demonstrated to be ultrasensitive and highly selective
for cholesterol and xanthine assay with detection limits of 0.03 and
0.10 μM, respectively. The fluorescence probe built was applied
to the determination of cholesterol and xanthine in human serum with
satisfactory results
Tumor-Associated Macrophages Regulating a Polymer Nanoplatform for Synergistic Treatment of Breast Tumors
Tumor-associated macrophages (TAMs) play a critical role
in tumor
progression and metastasis. Modulation of TAM polarization is one
of the most effective strategies to change the immunosuppressive tumor
microenvironment (TME). In this study, organic polymer nanoparticles
(CPHT) were prepared using hyaluronic acid (HA)-conjugated disulfide-bonded
polyethylene imide (PEIS) as a carrier through a self-assembly strategy.
These nanoparticles were modified by transferrin (Tf) and loaded with
chlorin e6 (Ce6). The results showed that CPHT had good dispersion
with a particle size of about 30 nm. CPHT gradually disintegrated
under the exposure with a high concentration of glutathione (GSH)
in tumor cells, proving the possibility for the controlled release
of Ce6 and photodynamic therapy. An in vitro test showed that the
uptake of CPHT in tumor cells was mediated by both HA and Tf, indicating
the active tumor-targeting capacity of CPHT. CPHT significantly downregulated
the ratio of CD206/CD86 and triggered the upregulation of immune factors
such as TNF-α and iNOS, suggesting the repolarization of TAMs.
We also found that CPHT effectively induced ferroptosis in tumor cells
through lipid peroxide accumulation, GSH depletion, and downregulation
of lipid peroxidase (GPX4) expression. Animal experiments confirmed
that CPHT not only effectively inhibited the growth of tumors in situ
but also significantly decelerated the growth of the distal tumor.
Elevated levels of CD86 and IFN-γ and decreased expression of
CD206 were observed at the tumor sites post CPHT treatment. These
results confirmed the value of CPHT as a multifunctional nanoplatform
that can tune the TME and provide new hope for tumor treatment