10 research outputs found
pH-Responsive NIR-Absorbing Fluorescent Polydopamine with Hyaluronic Acid for Dual Targeting and Synergistic Effects of Photothermal and Chemotherapy
In cancer therapy, optimizing tumor-specific
delivery, tumor distribution,
and cellular uptake of a drug is important for ensuring minimal toxicity
and maximum therapeutic efficacy. This study characterized the therapeutic
efficacy of a stimulus responsive and dual targeting nanocarrier for
a bioimaging-guided photothermal and chemotherapeutic platform. Hyaluronic
acid (HA) conjugated with triphenylphosphonium (TPP) and boronic acid
(BA) diol-linked β-cyclodextrin (β-CD) forms an inclusion
complex with paclitaxel (PTX), creating a shell-like composite on
a core of carbonized fluorescent polydopamine nanoparticles (FNPs-pDA)
applicable for photothermal therapy as well as bioimaging. The successful
diol cross-linking between core@shells generates nanocarriers [FNPs-pDA@HA-TPP-CD-PTX]
that can be used as an extracellular HA- and intracellular TPP-mediated
dual targeting system. The carbonized FNPs-pDA was cross-linked with
the boronic acid groups of HA-TPP-CD-PTX to promote the formation
of boronate esters for pH-mediated photothermal activity, which have
shown time dependent complete PTX release along with a photothermal
mediated response. The in vitro dual bioimaging and photothermal-chemotherapeutic
activities were compared between cancer and normal cells. Lysosomal
escape and live/dead cells staining confocal images highlight the
promise of this system, which might open up a new approach, a simple
and versatile method for site-specific synergetic drug delivery
Iron Oxide@PEDOT-Based Recyclable Photothermal Nanoparticles with Poly(vinylpyrrolidone) Sulfobetaines for Rapid and Effective Antibacterial Activity
Growing microbial resistance that
renders antibiotic treatment
vulnerable has emerged, attracting a great deal of interest in the
need to develop alternative antimicrobial treatments. To contribute
to this effort, we report magnetic iron oxide (Fe<sub>3</sub>O<sub>4</sub>) nanoparticles (NPs) coated with catechol-conjugated poly(vinylpyrrolidone)
sulfobetaines (C-PVPS). This negatively charged Fe<sub>3</sub>O<sub>4</sub>@C-PVPS is subsequently encapsulated by poly(3,4-ethylenedioxythiophene)
(PEDOT) following a layer-by-layer (LBL) self-assembly method. The
obtained Fe<sub>3</sub>O<sub>4</sub>@C-PVPS:PEDOT nanoparticles appear
to be novel NIR-irradiated photothermal agents that can achieve effective
bacterial killing and are reusable after isolation of the used particles
using external magnetic fields. The recyclable Fe<sub>3</sub>O<sub>4</sub>@C-PVPS:PEDOT NPs exhibit a high efficiency in converting
photothermal heat for rapid antibacterial effects against <i>Staphylococcus aureus</i> and <i>Escherichia coli</i>. In this study, antibacterial tests for repeated uses maintained
almost 100% antibacterial efficiency during three cycles and provided
rapid and effective killing of 99% Gram-positive and -negative bacteria
within 5 min of near-infrared (NIR) light exposure. The core–shell
nanoparticles (Fe<sub>3</sub>O<sub>4</sub>@C-PVPS:PEDOT) exhibit the
required stability, and their paramagnetic nature means that they
rapidly convert photothermal heat sufficient for use as NIR-irradiated
antibacterial photothermal sterilizing agents
Photoresponsive Fluorescent Reduced Graphene Oxide by Spiropyran Conjugated Hyaluronic Acid for in Vivo Imaging and Target Delivery
This present article demonstrates
the strategy to prepare photoresponsive
reduced graphene oxide with mussel inspired adhesive material dopamine
(DN) and photochromic dye spiropyran (SP) conjugated to the backbone
of the targeting ligand hyaluronic acid (HA; HA-SP). Graphene oxide
(GO) was reduced by prepared HA-SP accepting the advantages of catechol
chemistry under mildly alkaline condition enabling to achieve functionalized
graphene (rGO/HA-SP) as fluorescent nanoparticles. Due to containing
HA, rGO/HA-SP can bind to the CD44 cell receptors. The prepared rGO/HA-SP
is able to retain its photochromic features and can be converted to
merocyanine (MC) form upon irradiation with UV light (wavelength:
365 nm) displaying purple color. Photochromic behavior of rGO/HA-SP
was monitored by UV–vis and fluorescence spectroscopy. In vitro
fluorescence behavior, examined by confocal laser scanning microscope
(CLSM), of rGO/HA-SP in cancerous A549 cell lines assured that efficient
delivery of rGO/HA-SP was gained due to HA as targeting ligand. In
this work, we have shown that in vivo fluorescence image of spiropyran
is possible by administrating MC form solution of rGO/HA-SP using
Balb/C mice as in vivo modal. Accumulation of rGO/HA-SP in tumor tissue
from biodistribution analysis strongly supports the specific delivery
of prepared graphene to the target destination. The well tuned drug
release manner from the surface of rGO/HA-SP strongly recommends the
developed material not only as fluorescent probe for diagnosis but
also as a drug carrier in drug delivery system
Light Controllable Surface Coating for Effective Photothermal Killing of Bacteria
Although the electronic properties
of conducting films have been widely explored in optoelectronic fields,
the optical absorption abilities of surface-coated films for photothermal
conversion have been relatively less explored in the production of
antibacterial coatings. Here, we present catechol-conjugated poly(vinylpyrrolidone)
sulfobetaine (PVPS) and polyaniline (PANI) tightly linked by ionic
interaction (PVPS:PANI) as a novel photothermal antibacterial agent
for surface coating, which can absorb broadband near-infrared (NIR)
light. Taking advantage of the NIR light absorption, this coating
film can release eminent photothermal heat for the rapid killing of
surface bacteria. The NIR light triggers a sharp rise in photothermal
heat, providing the rapid and effective killing of 99.9% of the Gram-positive
and -negative bacteria tested within 3 min of NIR light exposure when
used at the concentration of 1 mg/mL. Although considerable progress
has been made in the design of antibacterial coatings, the user control
of NIR-irradiated rapid photothermal destruction of surface bacteria
holds increasing attention beyond the traditional boundaries of typical
antibacterial surfaces
In Vitro and In Vivo Tumor Targeted Photothermal Cancer Therapy Using Functionalized Graphene Nanoparticles
Despite
the tremendous progress that photothermal therapy (PTT)
has recently achieved, it still has a long way to go to gain the effective
targeted photothermal ablation of tumor cells. Driven by this need,
we describe a new class of targeted photothermal therapeutic agents
for cancer cells with pH responsive bioimaging using near-infrared
dye (NIR) IR825, conjugated poly(ethylene glycol)-<i>g</i>-poly(dimethylaminoethyl methacrylate) (PEG-<i>g</i>-PDMA,
PgP), and hyaluronic acid (HA) anchored reduced graphene oxide (rGO)
hybrid nanoparticles. The obtained rGO nanoparticles (PgP/HA-rGO)
showed pH-dependent fluorescence emission and excellent near-infrared
(NIR) irradiation of cancer cells targeted in vitro to provide cytotoxicity.
Using intravenously administered PTT agents, the time-dependent in
vivo tumor target accumulation was exactly defined, presenting eminent
photothermal conversion at 4 and 8 h post-injection, which was demonstrated
from the ex vivo biodistribution of tumors. These tumor environment
responsive hybrid nanoparticles generated photothermal heat, which
caused dominant suppression of tumor growth. The histopathological
studies obtained by H&E staining demonstrated complete healing
from malignant tumor. In an area of limited successes in cancer therapy,
our translation will pave the road to design stimulus environment
responsive targeted PTT agents for the safe eradication of devastating
cancer
Determination of Cancer Cell-Based pH-Sensitive Fluorescent Carbon Nanoparticles of Cross-Linked Polydopamine by Fluorescence Sensing of Alkaline Phosphatase Activity on Coated Surfaces and Aqueous Solution
The tumor-specific sensitive fluorescence
sensing of cellular alkaline
phosphatase (ALP) activity on the basis of host–guest specific
and pH sensitivity was conducted on coated surfaces and aqueous states.
Cross-linked fluorescent nanoparticles (C-FNP) consisting of β-cyclodextrin
(β-CD)/boronic acid (BA) and fluorescent hyaluronic acid [FNP(HA)]
were conjugated to fluorescent polydopamine [FNP(pDA)]. To determine
the quenching effect of this system, hydrolysis of 4-nitrophenyl phosphate
(NPP) to 4-nitrophenol (NP) was performed in the cavity of β-CD
in the presence of ALP activated photoinduced electron transfer (PET)
between NP and C-FNP. At an ALP level of 30–1000 U/L, NP caused
off-emission of C-FNP because of their specific host–guest
recognition. Fluorescence can be recovered under pH shock due to cleavage
of the diol bond between β-CD and BA, resulting in release of
NP from the fluorescent system. Sensitivity of the assays was assessed
by confocal imaging not only in aqueous states, but also for the first
time on coated surfaces in MDAMB-231 and MDCK cells. This novel system
demonstrated high sensitivity to ALP through generation of good electron
donor/acceptor pair during the PET process. Therefore, this fluorescence
sensor system can be used to enhance ALP monitoring and cancer diagnosis
on both coated surfaces and in aqueous states in clinical settings
Simple Microwave-Assisted Synthesis of Amphiphilic Carbon Quantum Dots from A<sub>3</sub>/B<sub>2</sub> Polyamidation Monomer Set
Highly fluorescent and amphiphilic carbon quantum dots (CQDs) were prepared by microwave-assisted pyrolysis of citric acid and 4,7,10-trioxa-1,13-tridecanediamine (TTDDA), which functioned as an A<sub>3</sub> and B<sub>2</sub> polyamidation type monomer set. Gram quantities of fluorescent CQDs were easily obtained within 5 min of microwave heating using a household microwave oven. Because of the dual role of TTDDA, both as a constituting monomer and as a surface passivation agent, TTDDA-based CQDs showed a high fluorescence quantum yield of 29% and amphiphilic solubility in various polar and nonpolar solvents. These properties enable the wide application of TTDDA-based CQDs as nontoxic bioimaging agents, nanofillers for polymer composites, and down-converting layers for enhancing the efficiency of Si solar cells
Visible-Light-Driven Photocatalysts of Perfluorinated Silica-Based Fluorescent Carbon Dot/TiO<sub>2</sub> for Tunable Hydrophilic–Hydrophobic Surfaces
In this study, a new hydrophilic–hydrophobic
transition
surface was designed via visible-light-induced photocatalytic perfluorinated
silica-based fluorescent carbon nanoparticles (FNPs)/TiO<sub>2</sub>. Perfluorinated silica–polydopamine hybrid FNPs (<i>f</i>-FNPs) were easily fabricated by carbonization in an emulsion
system consisting of tetraethyl orthosilicate and dopamine, followed
by the deposition of TiO<sub>2</sub> on <i>f</i>-FNPs, which
demonstrated the reversal from hydrophobic to hydrophilic nature during
successful photocatalysis. The synergistic effect of silica–carbon
and the deposited TiO<sub>2</sub> NPs led to the decomposition of
methylene blue under UV and visible light irradiation, demonstrating
that FNPs/TiO<sub>2</sub> sustains photocatalytic activity. The profound
contact angle with the catalytic kinetics curve and precise morphology
and extension of cells detach antifouling exceptionally unrestricted
the synergistic effect of silica–carbon on TiO<sub>2</sub> NPs
on a coated paper substrate. Given the interest in the manipulation
of hydrophobicity and hydrophilicity, this study can serve as a guideline
for the fabrication of photocatalytic surfaces where water spreads
completely
<i>In Vivo</i> Biodistribution and Toxicology of Carboxylated Graphene Quantum Dots
Photoluminescent graphene quantum dots (GQDs) have fascinating optical and electronic properties with numerous promising applications in biomedical engineering. In this work, we first studied the <i>in vivo</i> biodistribution and the potential toxicity of carboxylated photoluminescent GQDs. KB, MDA-MB231, A549 cancer cells, and MDCK normal cell line were chosen as <i>in vitro</i> cell culture models to examine the possible adverse effects of the carboxylated photoluminescent GQDs. The carboxylated GQDs are desirable for increased aqueous solubility. All cancer cells efficiently took up the carboxylated GQDs. No acute toxicity or morphological changes were noted in either system at the tested exposure levels. A long-term <i>in vivo</i> study revealed that the GQDs mainly accumulated in liver, spleen, lung, kidney, and tumor sites after intravenous injection. To reveal any potential toxic effect of the GQDs on treated mice, serum biochemical analysis and histological evaluation were performed. The toxicity results from serum biochemistry and complete blood count study revealed that the GQDs do not cause appreciable toxicity to the treated animals. Finally, we observed no obvious organ damage or lesions for the GQDs treated mice after 21 days of administration at 5 mg/kg or 10 mg/kg dosages. With adequate studies of toxicity, both <i>in vitro</i> and <i>in vivo</i>, photoluminescent GQDs may be considered for biological application
Highly Efficient Visible Blue-Emitting Black Phosphorus Quantum Dot: Mussel-Inspired Surface Functionalization for Bioapplications
The preparation of
blue-emitting black phosphorus quantum dots
(BPQDs) is based on the liquid-phase exfoliation of bulk BP. We report
the synthesis of soluble BPQDs showing a strong visible blue-light
emission. Highly fluorescent (photoluminescence quantum yield of ≈5%
with the maximum emission (λ<sub>max</sub>) at ≈437 nm)
and dispersible BPQDs in various organic solvents are first prepared
by simple ultrasonication of BP crystals in chloroform in the ambient
atmosphere. Furthermore, simple mussel-inspired surface functionalization
of BPQDs with catechol-grafted poly(ethylene glycol) in basic buffer
afforded water-soluble blue-emitting BPQDs showing long-term fluorescence
stability, very low cytotoxicity, and excellent fluorescence live
cell imaging capability